Electron microprobe microanalysis (EPMA), secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS) were used for charactering the surface composition of an Fe-Mn-Si-Cr shape memory alloy. The effect of annealing under vacuum on the surface composition of the alloy was studied. It was found that the amount of manganese decreased, while the amount of chromium increased in a surface layer by annealing. The thickness of the surface layer is of the order of ten micrometers, which is comparable to that obtained by conventional plating or coating. As a result, the surface of the Fe-Mn-Si shape memory alloy annealed under a vacuum exhibited better oxidation resistant than that of the as-lapped alloy.
- Secondary ion mass spectrometry
- Shape memory alloy
- X-ray photoelectron spectroscopy