Proceedings of the 3rd Annual International Conference on Material, Machines and Methods for Sustainable Development (MMMS2022)

Shear thickening polishing (STP) is a finishing process in which the abrasive slurry plays an important role and behaves as a non-Newtonian fluid. In this process, the cutting force are important factors that affect the surface quality of workpiece and machining performance. The cutting force is difficult to calculate accurately because many factors are changed during the STP process. Therefore, experimental modelling for cutting force is proposed in this paper. The influence of polishing speed, abrasive concentration, and working gap on the cutting force were investigated and evaluated by orthogonal experiment method. Experimental results demonstrate that the machining process of the workpiece is significantly improved under suitable cutting force conditions.

Granulation is the process of forming and aggregating primary powder particles into large particles called tablets or capsules. It also aims to ensure the tensile strength and quality as well as the easy storage of powder particles. The accumulation and production of tablets is essential to avoid segregation, creating a homogeneous mixture in many such materials. In addition to conventional granulation methods such as wet granulation and dry granulation, the review also outlines some new and improved methods from these two methods.

Fiber pulse lasers offer high power, well-controlled technical parameters, long lifetime, narrow pulse duration at nanosecond to femtosecond levels, and are utilized in many kinds of high precision manufacturing applications such as cutting, welding, and surface treatment. This study focuses on the use of a pulsed laser for polishing mechanical parts. A fiber laser source with flexible pulse emission modes, from 50 ÷ 1 million pulses in 1 s, pulse width 10 ÷ 300 nm allowing large instantaneous energy generation has been used. This feature allows for the removal of a very thin surface layer at the micrometer to a nanometer scale, with little thermal distortion of the substrate layer. Moreover, the polishing depth can be controlled accurately by changing the repetition rate, pulse width, and average power. Surface polishing of mechanical parts using a high-power laser brings out a lot of advantages such as accurately controlling the depth of the surface layer, high productivity, and environmental pollution prevention.

In recent years, one of the versions of the PAW-GMAW hybrid welding process is basically a combination of a PAW arc with a GMAW arc where the GMAW arc is emitted from the side-posited tungsten toward the nozzle orifice, the consumable wire fed along the torch axis through the orifice. Based on the configuration feature of PAW-GMAW hybrid welds, a combined heat source model as a hybrid heat source model is proposed for the numerical analysis of temperature fields in the PAW-GMAW hybrid welding process. It accounts for the volumetric distribution characteristics of plasma heat intensity along the direction of the workpiece thickness. The results show that the predicted geometry and locus of the fusion line in the PAW-GMAW hybrid weld cross-section are in good agreement with the experimental measurements. It lays a thermal stress–strain simulation of the keyhole PAW-GMAW hybrid welding process.

In powder-mixed electric discharge machining, the evaluation of material removal rate (MRR) in the finishing, semi-finishing, and roughing processes of the electrical parameters is of great importance in the field of machining science. Therefore, this study investigated the MRR of AISI H13 tool steel in the roughing process by EDM with tungsten carbide powder to clarify the effect of electric parameters and the concentration of tungsten carbide powder on MRR. This has implications in machining science. Based on the response surface method to form an experimental matrix and build a relationship model between process parameters such as peak current (Ip), pulse on time (Ton), and powder concentration (Cp) with MRR. The full regression equation was used to analyze the influence of variables on MRR by the ANOVA method. In addition, this study also found the optimal technology mode to achieve the largest MRR.

In this paper, we set up a mechanical displacement measurement system for an ultrasonic vibration tool at 20 kHz using an interferometer combined with a point-by-point signal processing system based on the lock-in amplifier method. The optical measurement system is a double-path heterodyne interferometer using a Zeeman frequency-stabilized He–Ne head with a few MHz beat frequency. To obtain such high-speed measurements, the interference heterodyne signals should be captured at a sampling rate of a few tens of MS/s to hundreds of MS/s. The calculations of the LIA algorithm should then be continuously performed in point-by-point architecture for each data point at each time or at the same sampling rate in real time. Experiments were created to clarify the measurability of the system. The experimental results have demonstrated that the system can measure the tool's ultrasonic vibrations with a peak-to-peak amplitude of ~ 100 nm at a vibration frequency of 20 kHz. The theoretical analysis and experimental results in this paper are presented.

In this study, we developed a self-propagating process where a graphene oxide (GO) film is chemically reduced and simultaneously incorporated with pseudo-capacitive cobalt oxide nanoparticles. For this process, a GO film was prepared by combining GO dispersion and cobalt oxide precursor. Once an end of the GO film was ignited in a controlled ambient condition, a reduction front rapidly swept along the film. The heat generated from the GO reduction not only advanced further reduction but also fueled the chemical reaction, to turn the precursor material into the cobalt oxide within the reduced GO (rGO). The morphologies, chemical compositions, and capacitive performances of the rGO were characterized to investigate the differences caused by various precursor content ratios. Then, the process was optimized to find the most stable and highest performing combination of incorporation precursor amounts and base temperatures. This study advances the efficient exploitation of the self-sustaining reduction of GO to quickly produce cobalt oxide incorporated rGO films, for supercapacitor applications on a large scale.

In this paper, combining theory and experimental process of face milling the SKD11 steel using circle inserts, the average values of cutting forces (CF) were built as a linear regression of feed per insert with high values of determination coefficients (more than 96.87%). Based on this relationship, the cutting force coefficients (CFCs) were determined including tangential shear force coefficient (Ktc) of 956.873 N/mm2, radial shear force coefficient (Krc) of 910.319 N/mm2, axial shear force coefficient (Kac) of -419.074 N/mm2, tangential edge force coefficient (Kte) of -15.023 N/mm, radial edge force coefficient (Kre) of 16.289 N/mm, and axial edge force coefficient (Kae) of 17.708 N/mm. The CF models were successfully applied to calculate and verify the CFs in facing process of SKD11 steel.

In this study, a hot forging process of the motorcycle Connecting Rod was performed from workpiece processing to the cutting process to achieve the final products. Starting from the cylindrical workpieces, the workpieces were processed by turning and upsetting methods. Applying the Finite Element Method (FEM), a series of forging processes were conducted using QFORM.10.1.6 to evaluate the quality and effectiveness of the forging process including maximum forging load, ability, detection of the laps, processing time, material cost, etc. By evaluating the quality and effectiveness of each forging simulation, the best solution was determined with quality requirements and saving the processing time and workpiece material by 31.48% and 24.66%, respectively.

This paper aims to deliver a study on the effect of process parameters on two objectives as weight and tensile strength of printed products. Experiments are conducted with different 3-level parameters as layer height (0.1, 0.15, 0.3 mm), infill percentage (20, 50, 80%), and raster angle (0°, 45°, 90°). Then, different methods are proposed to optimize process parameters. Taguchi's experimental design is applied in this paper to reduce the number of experiments, helping decrease cost. In detail, the weight and tensile strength of specimens are analyzed by the Taguchi method and ANOVA table. Then an optimal set of parameters is suggested for achieving a product with the best tensile strength and weight. Contribution analysis shows that infill density impacts weight and tensile strength most, with 88.7% and 39.1%, respectively. While raster angle also significantly influences tensile strength with a contribution of 36.2%, it almost has no impact on the weight variance. Layer height also is an influential factor. It affects tensile strength and weight with a contribution of 18.9% and 10.2%, respectively. For single-objective optimization, the best parameter combination for maximizing tensile strength is 0.1 mm layer height, 80% infill density, and 90o raster angles; and the optimal set for minimizing weight is 0.3 mm layer height, 20% infill density, and 90o raster angle. Besides, regression mathematic models for multi-objective optimization are constructed and evaluated for accuracy and reliability. Then, multi-objective optimization with a Genetic Algorithm is studied to identify an optimal trade-off set of parameters as advice to achieve suitable weight and tensile strength of the product according to users’ desire.

Titanium and titanium alloys are widely applied in many different industries because of their strength, good corrosion resistance, and especially high heat resistance. However, titanium and its alloys are difficult alloys to weld; after welding, the structure and mechanical properties of the alloy change greatly; affected the mechanical properties of the weld. In this study, the results are presented on the influence of the aging process on the microstructure and mechanical properties of the titanium and TiAl6V4 alloy welds. The micro-hardness distribution line of the weld after uniform heat treatment. After quenching and aging, the alloy's hardness is about 500HV. To the results of microstructure, after heat treatment and aging, the structure of the alloy in the welding zone is the α-phases; the widmanstatten structure, and β’ phase which have the form of stacked slabs. By the structure of welding, there are shown the appearance of bundles of β-type structures interspersed with α-phases.

Hardening surface is the method using the heat source (oxy-axetylen, plasma, electric induction with high frequency, laser…) to heat surface with the defined depth to the phase transition temperature, after that to make quickly to create a high hardness and abrasion resistance surface material layer. Therefore, the hardness of the detail received after surface hardening is one of the important factors that determine the quality of the product. This paper investigates the influence of technological parameters such as laser power, laser spot diameter on the workpiece surface, laser head movement speed to hardness when surface hardening of 9XC steel by laser ND: YAG laser. From the research results, the technologists can choose the technology factors to suit the requirements of the product.

Surface roughness (Ra) after machining is important for the workability and durability of machine parts. This study evaluates the influence of cutting parameters on Ra in the machining of C3604 copper. The influence of cutting factors, including V (m/min)- cutting speed, S (mm/min)–feed rate, and t (mm)—cutting depth, on the Ra has been investigated and represented by the graphs and exponential function. As a result, the S and t have a proportional effect on the Ra, where S is the parameter with the greatest influence on the Ra. Besides, the increased V leads to a decrease in Ra. The results of this study help technologists in selecting appropriate cutting factors to improve productivity and surface quality.

This paper presents the welding residual stress in T-joint fillet welds of low carbon steel by finite element analysis. Goldak’s double ellipsoidal heat source model is used in the numerical model by the finite element method. The material of S355J2G3 non-alloy structural steel is used. The thickness of steel plate in T-joint is 10 mm. A single pass weld is realized simultaneously in two sides of T-joint. The results of temperature distribution, residual stresses and welding deformations of double T-joint fillet weld performed by the MAG welding process are presented and discussed. The ESI SYSWELD finite element software that is the specialized software for welding and heat treatment processes was used for the purpose of this paper. Obtained results show that: in the flange plate, longitudinal stress (σx) and transverse stress (σy) components are significant; in the web plate, longitudinal stress (σx) component is significant; other stress components (σz, τxy, τyz, τzx) are insignificant.

This study presents a method of manufacturing the metal-bonded cBN grinding wheel by electroplating and the initial research results on the cutting performance of fabricated grinding wheels in the grinding of high-speed steel P18. The research results reveal that using the electroplating process with Watt’s solution, a layer of cBN abrasive particles can be strongly formed on the surface of the grinding wheel. The experimental surface grinding on the steel P18 shows that the fabricated grinding wheel has good machinability, resulting in the grinding wheel’s durability for up to 130 min at cutting conditions with V = 30 m/s, S = 300 mm/min, and grinding depth t = 5 ÷ 10 µm.

The experimental investigation of the axially compressive behavior of CFDST columns has been conducted by scientists from all around the globe. The objective of this numerical research is to evaluate the basic behavior of CFDST columns under axial compression. The simulation of circular CFDST columns utilizing normal strength concrete (NSC), high strength concrete (HSC), and ultra-high-strength concrete (UHSC) was done via finite element model (FEM) in ABAQUS software. This paper was proposed for the behavior of confined concrete with various concrete strengths. The curves of load versus strain and the ultimate load columns obtained from FEM were compared with those measured in the actual test to verify the accurateness of the FEM.

Obtaining optimal machining conditions to increase machining efficiency in the milling process is a difficult mission. This paper presents an experimental study and optimization of the machining parameters for the AA6061 in the high-speed milling process in this context. Material removal rate (MMR), tool wear rate (TWR), and surface roughness were the performance parameters measured in the experiments (Ra). The four variables studied were cutting speed, feed, depth of cut, and cutting time. The Support Vector Machine (SVM) technique is used to predict MRR, TWR, and Ra. Three error metrics were used to evaluate the model’s performance: Mean Squared Error (RMSE), Mean Absolute Percentage Error (MAE), and Coefficient of Determination (R2). As a result, the SVR models’ predictions for MRR, TWR, and Ra were correct. Three machine learning (ML) models and the NSGA-II algorithm were used to perform multiobjective optimization of the high-speed milling process. Fifty Pareto solutions were discovered in cases of high MRR, low VB, and low Ra. For high-speed milling AA6061, optimal machining parameter values are suggested.

Silent tool has long been a well-known product and attracted much interest in the field of metal cutting tools. When working, it is necessary to reduce the vibration so that the surface of the grinding wheel has a high gloss. When vibration occurs and develops, a shock absorber activates the damping system, producing a force against vibration, absorbing the energy that causes the vibration, thereby destroying the resonance and reducing the amplitude of oscillation. Using an anti-vibration halt is possible to achieve the surface finish level of 9 with an Ra value of 0.31 μm that improved completely when compared to a common halt (level of 6 with an Ra value of 1.41 μm). Therefore, by reducing the vibration using the shock absorber, the value of the cut mode parameters can be increased, simultaneously ensuring safety and minimizing the vibration tolerance, dimensional tolerances, and surface quality. Increased metal removal productivity results in minimizing production costs.

Heating the mold by using high-temperature fluid such as hot water, oil, … is the simplest and cos-effective solution. Different from the traditional cooling channel is just the straight hole through the mold, a conformal cooling channel was implemented based on the idea that the cooling channel path closely matched the molding profile, so the temperature transferred from the fluid in the cooling channel was distributed uniformly in the mold surface. In this study, three approaches included Taguchi, RSM, and ANN was used to found the optimum parameter of cooling channel. The optimum shape observed from three approaches proved that, conformal cooling channel show the better effectiveness than straight cooling channel when used for heating the mold surface.

This paper investigated the effect of annealing temperature on the microstructure and magnetic properties of the high-Si electrical steel using optical microscopy and a vibrating sample magnetometer. The melted steel containing 3.385 wt.% Si and 0.006 wt.% C was hot-forged and skin-passed into the 1 mm thickness sheet, then annealed at 800, 900, and 1000 °C for 2 h in the argon atmosphere. The results showed that the obtained samples had only the ferrite phase and no precipitation in the microstructure which was preferred for the electrical steel. As the raising of annealing temperature from 800 to 1000 °C, the average grain size of the ferrite phase increased from 216 to 350 µm. Although, both the maximum permeability and initial permeability of the samples were improved from 96.7 to 125 emu/g and 4.9 to 9.4 emu/g, respectively, the magnetic saturation had a trend to decrease from 211 to 182 emu/g. These magnetic properties of the steel samples referred that the annealing temperature of 800 °C was reasonable in this study condition.

This paper studies the residual stress in double-sided T-joint welding of non-alloy structural steel with different clamping conditions. The base material for the specimen of T-joint is S355J2G3 steel. The dimensions of flange plate and of web plate are 200 mm × 200 mm × 10 mm and 200 mm × 100 mm × 10 mm, respectively. The single pass welds on both sides of T-joint are realized simultaneously. The fillet welds in the T-joint are performed by the MAG welding process. Residual stresses results in the T-joint with different clamping conditions are presented and discussed. The ESI SYSWELD finite element software which is based on finite element method is utilized for thermal- mechanical analysis of this welding joint. Obtained results show that the residual stresses in the clamping boundary condition is much greater than that in the free boundary condition.

Tooth pick error is an important criterion to evaluate the quality of spiral bevel gear and directly affects the noise and vibration of the gear transmission. In this study, the spiral bevel gears were machined on the CNC generating machine Klingelnberg C27 and measured on the coordinate measuring machine (CMM) Klingelnberg P26 to evaluate the tooth pitch errors. Theoretical research on the causes of machining errors and analysis of measurement results showed that the critical cause of tooth pitch error is the error of the positioning and clamping surfaces. This study proposes a technological solution to reduce tooth pitch error by improving the quality of the positioning and clamping surfaces by grinding. Experimental results show that after grinding to improve the quality of the positioning and clamping surfaces, the tooth pitch error reaches an accuracy level from DIN 7 to DIN 4. The research results contribute to the quality control of spiral bevel gear machining on the Klingelnberg C27 CNC generator.

The goal of this research is to use Machine Learning (ML) models to forecast surface roughness in the manufacture of Polycarbonate (PC) using the Single-Point-Diamond-Turning (SPDT) process. Feed rate, cut depth, X-, Y-, and Z-axis vibrations, and spindle speed are the predictors of the SPDT process of ultraprecision turning. In this research, four regression approaches were used to predict surface roughness: linear regression (LIN), support vector regression (SVR), gradient boosting regression (GBR), and random forest regression (RFR) (denoted by Ra). The error metrics root-mean-squared-error (RMSE), mean absolute-error (MAE), and coefficient of determination (R2) were used to evaluate the predictive performance of prediction models. The GridSearchCV algorithm was used to find the optimum hyperparameters in order to improve the prediction ability of each model. The results showed that the SVR model performed best, with the lowest RMSE and MAE and the highest R2. This suggests that SVR was the most accurate model for predicting PC surface roughness using the SPDT procedure.

Laser focus detection techniques have been studied over years to advance laser processing. Recently, diffractive beam samplers proved to deliver high performance in detecting defocusing when implemented in laser systems. However, the lack of generalization in theoretical models proposed, where the general surface profile was not considered, makes it difficult to analyze the performance of the systems with nonplanar target surfaces. In this paper, a detailed geometrical optics based theoretical model of an autofocusing system using a diffractive beam sampler is presented. Simulation results proved the high sensitivity of the system in detecting defocusing and tilting of nonplanar target surfaces. This system has great potential in controlling laser focus position in practical laser processes.

In this study, the effect of machining parameters in Wire Electrical Discharge Machining, including the current, the cutting speed, and the winding speed, on the productivity of machining non-circular gears are analyzed using Taguchi experimental design and analysis of variance. Experimental results show that the cutting speed has the most significant effect at 95.93%. In contrast, the current and the winding speed have a negligible effect on the machining productivity, respectively, 0.13 and 3.94%. In addition, the trend analysis results of the effect of the machining parameters on the machining productivity based on the regression function also show that by changing cutting speed, the machining productivity drastic change. In contrast, the current change has a minimal effect on machining productivity.

In this paper, the objectives of tooth surface roughness and productivity of machining non-circular gears on wire electrical discharge machine are simultaneously optimized based on the overall evaluation index and the Taguchi method. The effect of machining parameters including the current, the cutting speed, and the winding speed on the overall evaluation index in the multi-objective optimization problem are evaluated based on the analysis of variance of experimental results. Analysis results show that the cutting speed has the most significant effect to the overall evaluation index at 67.47%. In contrast, the current and the winding speed have less and approximately the same effect on the overall evaluation index at 14.28 and 18.24%, respectively. This study has shown an effective criterion to solve the multi-objective optimization problem in machining non-circular gears on wire cutting machines.

The paper introduces experimental methods to determine the rule of wheel wear in surface grinding of Titanium alloy Ti6Ai4V. Experimental results are to determine the transformation rules of some output parameters that are considered to represent wheel wear. The research results show that the equations and graphs show the rules and are quite similar to previous studies. Grinding wheel wear clearly and uniformly affects the grinding ratio (G), cutting force (F) and surface roughness (Ra). Therefore, observing any of the above parameters can also predict the time point to stone ginding fix.

Solidification of liquid bridges appears in a vast number of applications. To better understand this process, we numerically study the solidification process of a vertical liquid bridge. The bridge is stuck to two disks (or rods) of the same size. The solidification starts from the stable shape of the bridge. We found that the upper and lower liquid–solid interfaces propagate with almost the same rate, and a ring (or protrusion) is created around the bridge when the bridge finishes its solidification.

The thermal effect is one of the most concerning and studying the case of heat transfer and thermal deformation in the aerospace structure in general and the structure of artificial satellites in particular is fundamental for a space exploration mission. Heat can appear when satellites are affected by solar radiation and radiation from planets. For spatial structures, the theory of heat transfer has been applied quite effectively. In this study, we applied Finite Element Method for analyzing temperature distribution and thermal deformation by using commerce software. The results showed that the analysis on thermal effect of a selected satellite model with the temperature difference of two opposite sides on the structure of the satellite. Specifically, the temperature distribution and thermal deformation are presented for the three materials. Finally, we evaluate the effectiveness of materials applied to satellite structures.

Fierce competition in the mechanical engineering industry requires manufacturing companies to optimize production. One of the factors that play an essential role in optimizing production is optimizing machining time. In general, the public process can do the job automatically by numerical machine control (CNC). Therefore, optimizing the guide engine can decrease its time value, resulting in increased power. In this search, we focus on using a drilling or laser tool on large metal sheets to create surface patterns using algorithmic architecture (ACO). The algorithm is implemented using Matlab 2010a. Simulation processes on Matlab and CIMCoEdit V7 software. The results show that the algorithm works well and generates a more efficient navigation tool than the conventional method. It is also possible to develop this algorithm for other machining methods, such as hole drilling, electric discharge machining, or plasma.

A new approach is proposed for focus positioning on a curved surface based on image processing method during laser machining. By analyzing the image in the CCD camera, the defocal direction and interval along z axis, rotation about x and y axes are obtained simultaneously. The images from the CCD camera are collected into a data set with the appropriate labels. In laser machining, the data from the CCD camera are acquired and matched with the above-mentioned data set. Subsequently, the one that is the closest to reality will be chosen. The more data in the data set, the higher the accuracy of the method will be. This is a fairly modern approach. It is expected that this method can be broadly employed for laser processing.

In this paper, we use a fiber laser with the wavelength of 1.06 µm to form multiple colors on titanium’s surface using color laser marking technology (CLM). An improvement in CLM is proposed, allowing to increase the working speed of CLM to 1000 mm/s, near the working speed of non-color laser marking. A new method to adjust the color on the material surface is studied. The method has capable of correcting the error in color and changing the failed color to the desired color. The paper also gives recommendations when using CLM technology in industrial scale.

The optimal fan angle (lateral reduction angle of the pin–fin) and fan radius ratio (ratio of the radius of the front section of the pin–fin to that of the rear part) were found in this work while other parameters remained constant. Six design points for fan angle and eight design points for fan radius ratio were used to estimate the heat transfer performance, friction factor, and area-averaged Nusselt number. According to the results, altering the fan angle and fan radius ratio can raise the Nusselt number by up to 8.4% and 6.1%, respectively, over the circular pin-fins example at Re = 25,000. At Re = 25,000, the channel with pin-fins in the shape of fans has a maximum heat transfer performance that is greater than the reference cases by 1.97% with a change in fan angle and 3.8% with a change in fan radius ratio.

Atomic layer deposition (ALD) is a new method in film-forming technology. With many advantages compared to other method, this method allows the creation of coatings of thicknesses less than 10 nm, thereby opens up many new research directions in coatings simulation and fabrication. This article studies the application of ALD in simulation and fabrication of broadband antireflective coatings on optical surfaces. The refractive indices of silicon dioxide and aluminum oxide, which are two materials used to create the antireflective coatings in this study were experimentally determined. A technique to determine the structure of coatings satisfying one or several conditions was also presented in this work. Such coatings may consist of symmetrical or asymmetrical cells, which are created using ALD. Measurement results of the received coatings showed that the reflectance does not exceed 2% in the wavelength range of 420–820 nm. Coatings with asymmetrical structures have lower reflectance than those with symmetric structures. The average measured reflectance of the symmetric and asymmetrical coatings in the range of wavelength 420–820 nm was 1.18% and 0.78%, respectively.

Laser focusing systems analyze the reflected laser beam from the specimen to return the defocus distance and direction, which also can be used for micro and sub-micro measurement. When curved or tilted surface is taken into account, this approach comes with inappropriateness because the reflected beam is deformed due to the differential incident angle of the incident beam. Employing image processing, we take further step to analyze the beam and manage to obtain both tilted angle and position of the specimen. A simulation model built on Zemax (Zemax LLC, Stansted, United Kingdom) works as theoretical model. The reflected beam is focused to a charge couple device (CCD) by a receiving lens. The focus pattern is then analyzed with the theoretical model. This technique returns high precision measurement results, including position, tilted angle and tilted direction of the tangent plane at the measured point.

This study towards the multi-response optimization of cutting parameters when turning 9XC heat treatment steel using Minimum Quantity Lubrication (MQL). The input parameters used are cutting speed Vc, feed rate Vf and depth of cut ap; and the responses examined are surface roughness and material removal rate (MRR). The objective of this research is to find the best combination of cutting settings to accomplish two targets simultaneously which are minimizing surface roughness and intensifying MRR. To find the ideal point, based on the Box-Behnken experimental matrix, the response surface methodology (RSM) consisting of 15 experiments is used. Experiments were carried out on the xxx lathe to collect data on roughness and MRR. Experimental models Ra and MRR are determined by using ANOVA. In this research, the multi-response optimization problem is solved by applying the desirability function (DF). The outcomes of the experimental study show that the optimized cutting parameters are Vc = 180 m/min; fr = 0.0759829 mm/rev; ap = 0.3 mm corresponding to Ra = 0.306147µm; MRR = 65.7155cm3/min; In addition, the impact of experimental variants on surface roughness in turning 9XC hardened steel using MQL is also analyzed and discussed.

This study examines the effect of toolpath types and wall angles on the formability of Al1050 aluminum sheets in the single-point incremental forming (SPIF) process. The results indicate that a continuous tool movement direction improves the deformation ability of the part compared to reversing the tool movement after each down step. The wall angle experiments reveal that for angles less than 60°, the workpiece does not fracture and has almost unlimited formability. However, when the wall angle is greater than 64°, the fracture height of the workpiece experiences a sudden change at a punch stroke of 28 mm. The fracture height gradually decreases as the wall angle increases to 90°. These findings provide a recommended design limit for parts made from Al1050 aluminum sheets in the SPIF process.

This work measures the laminar combustion characteristics of gasoline-air mixtures at different equivalence ratios (ϕ = 0.8, 0.9, 1.0, 1.1 and 1.2) using the pressure rise method combined with a constant volume combustion chamber. The pressure rise method requires a more complex analysis but has the advantage that a single experiment generates data at engine-like conditions. The laminar combustion is characterized by laminar burning velocity (SL), heat release rate (HRR), flame developing time (FDT), and flame rising time (FRT). SL value was then obtained by a least-square fit of the observed pressure–time p(t). SL was calculated at 10% to 90% of HRR to avoid the effect of ignition energy and flame-wall interaction, where HRR was directly taking the time differentiation on p(t). FDT was determined as a time duration from the start ignition command to 10% of HRR, while FRT is the time duration from 10 to 90% of HRR. The results revealed that the value of SL reaches its maximum value of 42-cm/s at ϕ ≈ 1.0 ÷ 1.05; beyond this range, SL decreases. The SL values are quite close to the previous data obtained by different techniques, showing the reliability of the pressure rise method in this study. HRR is proportional to SL, while FDT and FRT are inversely proportional to SL when varying ϕ from 0.8 to 1.2. The results of the lean gasoline-air mixture (ϕ < 1.0) also suggest the necessity of enhancing flame propagation when applying the lean burn technology to improve engine thermal efficiency and NOx emission.

Biogas and hydrogen are renewable fuels but their properties are very different. Biogas contains CO2 with a different component, so its calorific value and flame rate are low, affecting the quality of the combustion process of the engine. Hydrogen has a flame spread rate 10 times higher than methane. On the other hand, hydrogen can burn with a very poor mixture, with low ignition energy. Because of this property, hydrogen will help improve the combustion quality of biogas engines. In this research, we will simulate the influence of the equivalence ratio, biogas composition, and hydrogen content in the mixture on the indicated engine cycle work and CO, HC, and NOx emissions on the Honda GX200 engine. The optimal equivalence ratio changes from 1.05 to 1.01 as the CH4 composition in biogas increases from 60 to 80%. The rate of heat generation and NOx emissions increases with the hydrogen content of the fuel mixture and the volumetric hydrogen content of the methane mixture of about 20% is optimal to achieve the harmonic between engine performance and emissions. Under optimal operating conditions, the addition of 20% hydrogen content into biogas is found to improve the indicated engine cycle work by 6%, to reduce CO and HC emissions by 5–10 times. However, it increases NOx emission by 10–15% compared to neat biogas fueling mode.

Neurological disorders, including neurodegenerative diseases such as Alzheimer's and brain tumors, are a leading cause of death and disability across the world. Accurate image segmentation of these cells with the help of computer vision could lead to new and effective drug discoveries to treat the millions of people with these disorders. In this paper, UNet++ (Resnet34) produces more accurate cell segmentation in challenging images such as high-resolution images and small cells. The results illustrate improvements to the broad UNet architecture, which is a robust architecture for segmenting medical image. The experiments demonstrate that UNet+ + with a supervised encoder-decoder structure achieves evaluation metrics with an average IoU of 58% and pixel accuracy of 96%. This method allows to detect the large numbers of medical cell in a short time and can be applied to automated cell imaging and analysis system.

Directed energy deposition (DED) is a popular group of metal additive manufacturing (AM) technologies. The DED processes uses either a laser source or an arc source to melt the metal in form of powder or wire and directly deposited melted metal into the part according to successive layers. The technological performance of these technologies has been proved in terms of fabricating dense parts from different metals. However, the environmental performance of these processes is not analyzed comprehensively yet. In this paper, we aim at evaluating the environmental impacts related to the wire-arc DED (WA-DED) and powder-laser DED (PL-DED) based on the manufacture of a test part. The goal, scope and system boundary were defined, and the data for life cycle assessment were collected from the literature and Ecoinvent-3.5 database. The environmental impacts related to each manufacturing process were computed with the aid of the OpenLCA software. The outcomes of the research enable choosing the most suitable manufacturing method in the environmentally friendly point of view.

The solution of adding hydrogen and oxygen gas (called HHO gas, hydroxyl gas) to traditional fuel has been interested by scientists in recent years to improve the combustion process of internal combustion engines. This article presents the content of designing and manufacturing HHO gas generation system by water electrolysis method with electrolytic energy source from available generator of Honda Lead 100cc motorcycle and energy from regenerative braking system. This regenerative braking system located at the front wheel of the motorcycle helps to brake the motorcycle and recovers electrical energy during braking. When the motorcycle is operating normally, the generator is idling, so the motorcycle still operates smoothly. When the brake is pressed, the generator will generate a magnetic field to brake the motorcycle and generate electricity, which is stored in the battery and then supplied to the HHO generator. The power test results obtained from regenerative braking when braking at a speed of 50 km/h are 543.46 W, the ability to generate HHO gas reaches a flow of 0.6 l/min. Test results of the motorcycle on the Super Dyno 50L test bench, the power of the motorcycle increased by 14%, the fuel consumption of the test motorcycle on the road decreased by 13.2%.

Application of renewable energy to replace fossil fuels is an urgent issue to reduce greenhouse gas emissions, contributing to the implementation of the Net Zero strategy. Vietnam is a tropical country thus biomass is largely abundant. Therefore, gasification of biomass through RDF to produce syngas to power generators is potential for our country. To ensure storage possibility and to improve fuel uniformity, biomass from agricultural waste is processed into RDF. RDF is then gasified to produce syngas to fuel internal combustion engines. This work contributes to the experimental study of gasification of RDF biomass in a downdraft gasifier. The results show that the maximum temperature of the gasifier body ranges from 600 to 800 ℃, when the inlet air flow changes from 200 to 300 L/min. The location of the reaction zone and the maximum temperature zone is independent with the air flow supplied to the gasifier.

Tubular products, which are hydrostatically formed, have proven their wide application in many industries, especially in the automotive—motorcycle and aerospace industries. Compared with other manufacturing processes, tube hydrostatic forming (THF) provides parts with better quality and lower production costs. In order to obtain parts that satisfy design requirements such as geometric shapes, material thickness distribution, mechanical properties and stiffness, the study of the influence of technological parameters such as internal fluid pressure is and axial feed is extremely important and urgent. Numerical simulation of the process of tube hydrostatic forming to manufacture T-shaped joints through finite element (FE) modeling on Abaqus software helps scientists have a more intuitive view of the ability to create product quality as designed, as well as optimizing input parameters, output parameters in this process. As a result, it will save more money and time in the trial and error phase, and bring quality products to market faster. This study aims to find the combination of THF parameters that maximizes the height of the protrusion and minimizes the thinning ratio of the expansion zone. The results obtained from numerical simulation will be used to develop THF experiment and compare the results from the simulation with the experiment later.

Tube hydrostatic forming (THF) is one of the fascinating forming processes, applied to produce hollow tubes through a high-pressure fluid source inside the tube. Tubular products manufactured by this method have demonstrated many advantages such as achieving complex structure, stiffness, higher mechanical properties, reduced weight, low springback. Their diversity and wide application in key sectors such as the automotive, ship-building, aerospace, and oil and gas industries increasingly demand higher standards of quality. Therefore, this paper presents a study on three axial feed options in the THF process to fabricate components with complex and asymmetrical structures—60° Y-shaped CDA110 copper material components. The study was carried out on the basis of numerical simulation using Abaqus software to evaluate the quality of components to be shaped through 5 criteria including The profile of component, Section thickness, Total and effective protrusion height, Mises equivalent stress, and Plastic deformation components. Research results can be applied in product design and more efficient process design, optimized computation, and control of input and output parameters for more cost and time savings in the trial and error stage, quickly bringing quality products to market.

Selective Catalytic Reduction (SCR) is one of the most efficient technologies to reduce NOx emissions in the exhaust gas of diesel engines. In the SCR system, urea solution is injected into the hot exhaust gas, chemically decomposed to ammonia as a reducing agent that reacts with NOx to form N2 and H2O over the catalyst surface. However, for a specific SCR system, the NOx conversion efficiency depends on many factors such as exhaust gas temperature, exhaust gas flow rate, and ratio of NO2/NOx… This study aims to investigate the effect of some properties of diesel exhaust gas on the NOx conversion efficiency of an SCR system. The SCR system is designed for bus diesel engines and is modeled by using AVL Boost software. The results show that the NOx conversion efficiency increases as the temperature of the catalyst increases from 50 to 450 °C. The NOx conversion efficiency is inversely proportional to the exhaust gas flowrate. When the NO2/NOx ratio increases from 0 to 50% the NOx conversion efficiency increases gradually. Increasing the NH3/NOx ratio increases the NOx conversion efficiency, and the optimal value of the NH3/NOx ratio is 1.

In this study, we examine the mechanical and electronic properties of the hydrogenated-biphenylene (HB) monolayer using Ab initio calculations. We find that the HB monolayer has anisotropic mechanical properties. The Young’s modulus of the HB monolayer is 222.73 (N/m) and 155 (N/m) along the x and y directions, respectively. The ideal strength of the HB monolayer along the x direction (21.23 N/m) is higher than that along the y direction (13.79 N/m). Moreover, our obtained results demonstrate that the HB monolayer is an indirect bandgap semiconductor at the equilibrium state, with a bandgap of 3.45 eV. We find that an indirect to direct bandgap semiconductor transition occurs at the strain of 12% along the x direction. The results presented in this study elucidate the intrinsic properties of HB monolayer under the tensile strain, which are useful for making devices based on HB monolayer.

Energetic Macroscopic Representation (EMR) has been developed for analyzing and controlling mechatronic systems since 2000. In recent years, EMR has been researched and applied by scientists in energy controlling hybrid vehicles. This paper is an initial study on building an energetic model of a single-cylinder engine using natural gas fuel, based on the principle of energy conservation and inverted control structure of the system. The aim of this paper is to control engine torque by controlling supplied fuel mass based on engine load characteristics. When analyzing the simulation results, there was still a delay in the control process, which was explained in this paper. Future research is expected to overcome the above issue. The obtained results provided a good basis to study the heat transfer to the emissions and the coolant water of the engine, including solutions to recover heat emissions.

This paper presented the effect of port fuel injection pressure on performance and emission characteristics of a natural gas SI engine. The research method carried out in this study is experiment on a single-cylinder diesel engine converted into a research CNG engine. The injection pressure was varied of 3 bars and 4 bars, at different engine speeds (1032 rpm, 1205 rpm, 1408 rpm, 1609 rpm and 1829 rpm). The experimental results indicated that injection pressure has a significant effect on engine power, torque and exhaust emissions. Increasing injection pressure from 3 to 4 bars will improve power and torque at all speeds. CO, HC and NOx emissions are reduced when the engine operates at higher speeds.

Improving the propulsion efficiency of the engine has always been the goal of the propeller designers. Various propeller configurations have been introduced in the past to meet this goal, and contra-rotating propellers (CRP) are no longer a new concept. The CRP is one of the propulsion engines that can help to improve the propulsion efficiency compared to traditional single propeller engines based on its ability to recover the energy lost due to rotation behind the propeller. Using CRP to replace the traditional propeller engine will help save the amount of fuel needed. This advantage makes the design and analysis methods for CRP receive much attention. Therefore, a new set-up calculation design method based on lifting line theory is used. The second step is design the shape for the propeller corresponding to the vortex distribution just found. Finally, the process is repeated with many different configurations to find the optimal design. The main objective of the study is to determine the design calculation method by using numerical model (determining the optimal vortex distribution) for CRP so that the selection time between methods can be reduced. Thereby, it makes the basis for the next design steps more convenient.

In this work, the heat transfer performance of circular pin–fin arrays is analyzed by dealing with Reynolds-averaged Navier–Stokes (RANS) equations and compared to the fan-shaped pin–fin arrays. The heat transfer and flow inside a rectangular cooling channel are evaluated using the k-ω and SST turbulence models with the range of Reynolds number of 5000 to 25,000. The result yielded that the heat transfer performance is increased when using fan-shaped pin–fin arrays. The greatest difference is that the fan-shaped pin-fins channel has a smaller Nusselt number at Re = 5000 than the circular pin-fins channel. However, Re = 25,000 changes the least—by 0.11%—of all the values. The friction factor of the fan-shaped pin-fins is lowered greatest at Re = 25,000 as opposed to the 2.04% friction factor of the round design. The fan-shaped pin–fin channel outperforms the circular pin–fin case by 2.9% at Re = 10,000, which is the point at which the heat transfer properties of the two cases differ the most.

This paper presents the results of an experimental study on the addition of Hydrogen-Rich Gas (HRG) to a 4-stroke, 4-cylinder gasoline engine using a carburetor. The authors have designed and calculated the necessary HRG system for the engine; installed the HRG system for a Toyota 3Y engine using a carburetor; tested the engine’s exhaust gas concentration, fuel consumption, and power of a Toyota 3Y engine with and without the HRG system. Research results show that with a Toyota3Y engine using a carburetor with an HRG system, engine power increases by about 9.5%, fuel economy is about 20.6%, CO concentration is reduced by 37.5%, and HC decreases by about 34%, and CO2 concentration decreased by about 51%.

Air-spindles are extensively adopted in machines that require high speed and high rotation precision. There are three air-fed types of air spindles inserted with small orifice holes and pockets, porous holes, orifice holes, and grooves. Among these air-fed types, the orifice holes and grooves have several advantageous features such as structural simplicity, easy manufacturing, and low cost. One of the most important aspects in designing an air spindle is to ensure the stiffness of the air thin film, which maintains center stability and rotation accuracy. In this study, three models of air-fed grooves were compared to evaluate their stiffness. By using the Computational fluid dynamics (CFD) simulating method to validate the symptoms, we came with the conclusion of this study is that the independent separation of grooved air bearings in air-spindles can achieve stiffness better than other cases. In details, from the well-known advantages of CFD simulation: time, accuracy, the completion if its theory; the method is used to calculate the necessary parameters to compare the difference between the two models. The main conclusion of this study is that the independent separation of grooved air bearings in air-spindles can achieve stiffness better than other cases.

This paper focuses on simulation of Scramjet engine’s combustion chamber using 3D-RANS equations with k-ω SST turbulence model and Non-premixed Flamelet combustion model. The simulation results validate this complex simulation model by comparing to experimental results made in Germany. Then, a flame holder—cavity—is added inside the combustion chamber to change combustion efficiency. The improvement of this modification is verified by comparing the results from different types of cavities to the result from the default geometry with 3.0% to 6.3% better of combustion efficiency value at different cross-sections.

The current equipment and materials used in UAV manufacturing have only been tested under normal conditions while UAVs operate in a wide range of environment conditions. Many UAVs fly at high altitude where the temperature drops significantly. Low ambient temperature will affect the operation of electronic components and structure of the UAVs. Therefore, it is very important to study the simulated low temperature environment equivalent to the operating condition of the UAV to check the operability, structural strength, and minimize the risk of damage and destruction of the UAV. This paper focuses on research, analysis, building principles, deployment of design diagrams, test chamber simulation and fabrication that have relatively controlled cooling rates based on the spread of cooling liquids.

This work studies the aerodynamic properties and structural model of horizontal-axis wind turbine rotor with capacity of 300 W by using QBlade software. In addition, the critical endurance is also preliminarily evaluated according to IEC 61400-2 standard. The interdependence between of rotor solidity, tip speed ratio, pitch angle, and maximum power coefficient is an important factor to design a small wind turbine rotor for low power application. The configuration of NACA 4412 airfoil is adopted for design and simulation. The performance with different Reynolds numbers, tip speed ratios and airfoils are the key topics to be examined and discussed in detail. The chosen model, after the calculation, is also carried out in this work to verify the simulation results on QBlade software. Simulation results indicate that the hollow blade (no spar) not only reliably satisfies the durable condition but also has the lightest mass (by using E-glass/epoxy composite).

This work uses machine learning (ML) models to estimate the roughness of surface texture in the manufacture of aluminum by ball end milling operation. The ball end tool, inclination angle, feed rate along the Y-axis, feed rate along the X-axis, spindle speed, and depth of cut are the production process input parameters. Four ML methods were used in this study to estimate the roughness of surface texture: Linear Regression (LIN), Extreme Gradient Boosting (XGB), Gradient Boosting Regression (GBR), Support Vector Regression (SVR) and Random Forest Regression (RFR) (Ra). Different error metrics, such as root mean squared error (RMSE) and mean absolute percentage error (MAPE), were used to investigate the effectiveness of ML models. The GridSearchCV algorithm was used to find the optimum hyperparameters in order to improve the predictive effect of each model. The results exhibited that the XGB model performed the best (exhibiting the lowest RMSE and MAPE using both training and testing datasets).

The content of this article aims to use the solution to control an automobile’s suspension system. A dynamic model is built to describe the automobile’s oscillations with five state variables. The SMC (Sliding Mode Control) solution with the high-order derivative of output signals is utilized in order to direct the hydraulic actuator equipped with an active suspension. Numerical simulation is performed with two specific cases. In each case, 3 situations are evaluated. The input parameters are the excitation signals from the road, and the output parameters include the sprung mass’s vertical displacement and vertical acceleration. In the first case, the mean and maximum displacement values for the automobile utilizing an active suspension directed by a SMC solution are only 15.59% and 16.83%, compared to the car using a typical system. In the other case, this average displacement value is only 14.14%. Besides, the vertical acceleration of a car is also strongly declined once the SMC algorithm is utilized. As a result, the comfort and smoothness of a vehicle have increased considerably. The SMC method should be combined with other methods to advance the controller’s quality for the suspension system.

In recent years, improvements in hip replacement procedures have had better outcomes for patients after surgery. With the development of 3D printing technology, artificial hip joints will be designed and manufactured to match each case. The mechanical factor is the most important affection in the longevity of a hip implant’s life, coupled with biocompatibility and strength of materials. In this study, the author will propose a process to design and manufacture a replacement hip joint suitable for the patient’s hip size and structure from CT (Computerized Tomography) or MR imaging. The hip joint is made of non-metal materials such as HDPE (High-Density Polyethylene) and PEEK (Polyether Ether Ketone) which have biocompatibility and mechanical properties like bone. The effects of materials and parameters design of the artificial hip joint (AHJ) on its mechanical behavior such as the equivalent stress and total deformation in moving and applying load were investigated using the finite element method. The results gave a hip design made of HDPE and reinforced carbon fiber PEEK materials with a proposed design suitable for the studied patient.

The paper details studying the discrete-event simulation modeling methodology and its application in production manufacturing in Viet Nam. The manufacturing industry is a complex discrete event dynamic system, and accidents may occur in the production line. For example, poor equipment layout design, or idle waiting state of personnel and equipment due to station blockage of the production line, or the warehouse management is unreasonable, the supply exceeds the demand, or the supply exceeds the market, resulting in loss or waste. It isn’t easy to get the optimal solution by the traditional analytical method, but simulation can solve it. Mainly, this research focuses on problem formulation, setting of project objectives, model conceptualization, verification and validation, and experimental design.

Sodium alginate (SA), cross-linked by calcium ions, is widely used as bioink in 3D bioprinting. The coaxial printing method integrating with the extrusion-based method offers the merit for simultaneously printing multi-materials such as SA and calcium chloride (CaCl2). A design of an adapter based on coaxial printing is developed and evaluated to crosslink the SA solution immediately after deposition through the nozzle. The printability of SA solution at different flow rates and concentrations of SA and CaCl2 is investigated by computational simulation and experimental method to figure out the optimal printing condition. The results show that the concentration of SA and the flow rate of solutions have significant effects on the printed line width while the concentration of CaCl2 only affects the adhesion of the printed line on the substrate.

Using 3D-RANS equations with the k- ε turbulence model, this paper shows four parametric studies of axisymmetric rotor injection on aerodynamic characteristics of a single-stage transonic axial compressor. The injection design variables, including mass flow rate, circumferential coverage angle, location, and width are established to find their effects on the compressor performances, comprising total pressure ratio, peak adiabatic efficiency, stall margin, and stable range extension. The simulation results confirm qualitatively and quantitatively that in most cases of the reference designs with the rotor injection, the compressor aerodynamic outcomes are improved considerably. The ideal design was found to augment the adiabatic efficiency, total pressure ratio, and stall margin by 0.67, 0.52 and 2.28%, one-to-one.

The paper presents a thermo-gas-dynamic model of the gas chamber of automatic weapons using the gas extraction principle. The problem is solved using the differential form equation of the mass and energy conservations, the volume variation considering the loss of gas flow and the loss of energy due to heat transferring. The results show that the maximum pressure in the gas chamber is about 2.7 times lower than the average pressure in the bore of the AKM assault rifle at the time of the beginning of gas extraction, the impulse of the extraction equipment is a large extent and the energy loss of the powder gases flowing from the bore into the gas chamber is relatively amount. The proposed model can be used for calculating and designing of firearms using the principle of gas extraction.

The process of firing a gun comprises the conversion of energy from the chemical energy of the propellant into the kinetic energy of the bullet, the kinetic energy of the automatic components and other forms of energies. In order to determine this energy distribution in an automatic gun operating on the principle of gas extraction, the processes occurring in the barrel and other gas chambers are considered according to the method of thermo-gas-dynamics. Results show that the kinetic energy of the bullet at the moment it leaves the muzzle is approximately 34% of the total energy released on firing. The remaining energy of the powder gas is wasted in thermal and gaseous effects that serve no useful purpose. Clarifying this energy conversion provides the basis for improving the energy efficiency of the shot.

In this paper, we introduce a method to optimize toolpaths on 3-axis CNC milling machines when machining parts with conical surfaces. The method is based on a genetic algorithm, in which individuals are encoded by binary strings. Genetic operators such as crossover and mutation are also considered with appropriate requirements. A suitable environment is initialized accordingly to fit individuals and optimize the problem. A script is built on Matlab2010a to determine the best individual, and the results are then simulated on CimCo Edit V7 to evaluate the effectiveness. The results show that our proposed method is entirely feasible, and the optimized toolpaths result in better outcomes than traditional methods.