The Application of the Ziebold Correction Procedure for Probe Data to Three Ternary Copper-Base Alloys

Abstract

For the quantitative analysis of a 65 Cu-30 Ni-S Fe alloy, a 96 Cu-3 Si-1 Mn alloy, and a 78 Cu-20 Zn-2 Al alloy, the Ziebold empirical method of correcting electron-microbeam-probe data was used. Four binary standards, of single-phase Cu-Ni, Ni-Fe, Cu-Mn, and Cu-Zn alloys, were cast and the a correction factor found for each element in each binary by Ziebold's relationship (1 – K)/K – α (1 – C)/C, where K – I/I₀ found in the probe and C is the weight fraction found by wet chemistry. The ARL EMX probe was used at 30 kV with a 25-μ beam diameter to negate inhomogeneities. Experience with these binaries indicated that in the presence of secondary fluorescence, the experimental α values agreed poorly with theoretically calculated K values; however, where secondary fluorescence was negligible, agreement between the experimental and theoretical α values was good. The α values for Cu–Si, Cu–Al, Al-Zn, and Mn–Si alioys, were therefore calculated from the theoretical equations. The α values for Cu–Fe alloys were also calculated from theoretical considerations because single-phase binaries over the composition range of interest could not be made for this system. All these α values were used in Ziebold's ternary equations to correct probe data (again using a 25-μ beam) from specimens of Cu–Ni-Fe, Cu–Si–Mn, and Cu-Zn–Al. These results were compared to wet-chemistry analyses for the same specimens with quite good correlation between the two sets of data. Calibration curves for the binary systems Cu-Ni, Cu-Fe, Ni-Fe, Cu-Mn, Cu-Si, Mn-Si, Cu-Al, Cu-Zn, and Al-Zn were made and are reproduced.