Robust parameter design of the procedure for determining the chemical composition of copper alloys by X-ray fluorescence

The paper offers a brief overview of the modern procedures for determining the chemical composition of copper alloys along with the applied methods of analytical control. It has been shown that to obtain reliable and comparable results of measuring the mass fractions of copper alloys elements within wide ranges of values, the most suitable procedures are based on the X‑ray fluorescence method, implemented using portable X‑ray fluorescence spectrometers. In order to select the optimal values of the influencing quantities when determining the chemical composition of copper alloys, a robust parameter design of a quantitative chemical analysis procedure was carried out using X‑50 Mobile X‑ray fluorescence spectrometer. The use of robust parameter design as opposed to conducting a full factorial experiment when developing a measurement procedure makes it possible to optimize the measurement conditions and obtain results of the required accuracy with a limited number of experiments and a maximum number of controlled factors. An example of drawing up an experimental plan for the parameter design of such procedure is provided, and a statistical analysis of the measurement results is carried out. The authors have analyzed and selected the optimal measurement conditions (influencing quantities), which ensure the minimum error of the results of measuring the mass fraction of elements. By selecting the optimal values of the influencing quantities based on the results of robust parameter design of the quantitative chemical analysis procedure, it became possible to increase the accuracy of determining the chemical composition of copper alloys and, hence, improve the reliability of the product quality control results at a relatively low cost. Such approach can be recommended for use by analytical laboratories developing procedures of quantitative chemical analysis for metallurgical enterprises.