Study On XRF Technique Applied In Determination Of Major Element In Copper Alloy

Copper and its alloy have excellent performances of electric conductivity, thermal conductivity, corrosion resistance and different contents of elements in copper alloys directly affect their metallic properties. Therefore a quick and accurate analysis of the chemical elements in copper alloy is especially important to the trade and processing in copper alloy production. Using XRF technology to analyze copper alloy has the advantage of being fast in analysis, wide in range of detection and able to do in situ nondestructive analysis. In this article, portable X fluorescence analyzer based on X-ray tube is employed to do a fast analysis and investigation of the main elements in copper alloys which are mainly confined to brass, bronze and copper-nickel alloy in this research. This study has the following main results.1. Strength formula of primary and secondary fluorescence of homogeneous and heterogeneous X-ray is constructed and a theoretical equation of mathematic relation between content of elements in copper alloys and fluorescence strength is also established. This research specifies the influence of matrix effect between different elements and focuses on the study of absorption enhancement between different elements in copper alloy.2. Sample preparation of brass, bronze and copper-nickel alloy are made according to National standards (GB/T5231-2001). In this article, the characteristic of element contents changing with the range of constituents in copper alloys in study is analyzed and the solution of granularity effect is proposed.3. The tube voltage and current under the optimal excitation conditions of X-ray tube is 22kV and 8μA respectively according to massive empirical datum.4. This research uses different wavelet function to do sleeking, noise reduction, background deduction and heavy peak decomposition to the X-ray in measurement. The result shows that it will achieve the best effect by using sym7 wavelet function in the treatment of brass and manganese bronze. In copper-nickel alloy, it should first use sym7 wavelet function and then use coif4 wavelet function to do two wavelet processing to achieve the best effect.5. This research shows that compared with the recommended value, contents of copper and zinc in brass have a maximum relative error of 1.7% and 4.9%, copper and manganese in manganese bronze 0.4%and 6.6%, copper and tin in bronze 1.2% and 4.3% and copper, nickel, and cobalt in copper-nickel alloy 1.5%, 6.7% and 6.3%.To summarize, it is fast, accurate and effective to use portable X fluorescence analyzer to do analysis of copper alloys. Moreover, this method will not destroy the sample and cover a wide range of detection, which will meet the needs of production.