材料期刊网

The oxidation of Ti-48Al-8Cr-2Ag (at.%) was studied for 50 h at 900 and 1000 degrees C. The microstructure of the oxide scales was characterized by means of scanning-electron microscopy (SEM) and high-resolution electron microscopy (HREM). The results showed that the mass gain of the alloy at 1000 degrees C was lower than that at 900 degrees C. At 1000 degrees C, a continuous and dense scale of quite pure Al2O3 formed, but at 900 degrees C, a complex scale with an outer layer of Al2O3 + TiO2 and an layer of inner Al2O3. A Laves phase and a Z-phase were found at the scale/substrate interface, which might be a factor beneficial to the formation of Al2O3.