Oxidation of the turbine blade material CMSX4 studied by X-ray diffraction

The high-temperature oxidation behaviour of the turbine blade material CMSX 4 was examined by in situ X-ray diffraction in the temperature range betwee n 700 and 1200 degrees C. The intensities of the X-ray reflections of the o xides formed during the oxidation process were calculated and plotted as fu nctions of time. Their curves show the oxidation process. After cooling dow n an ex situ electron microprobe analysis was carried out to determine the sire of the oxidation products within the oxide scale. The results reveal t hat CMSX4 changes its oxidation behaviour between 900 and 1000 degrees C du e to the solution of the gamma'-phase. The presentation shows how in situ X -ray diffraction and electron microprobe form a complementary combination.