The stability of Cr3C2/Ni3Al composite at elevated temperature

The phase stability and chemical stability of Cr3C2/Ni3Al composite at 1000 degrees C have been investigated through long-term aging and oxidation experiment. After long-term aging at 1000 degrees C, Cr3C2 phases kept stable, a few gamma phases separated out and strengthened the Ni3Al matrix, which resulted in the hardness Of Cr3C2/Ni(3)AI composite increasing. On the other hand, Cr3C2/Ni3Al composite possessed good oxidation resistance. The protective oxides that mainly consisted of alpha-Al2O3 were formed and the Cr3C2 phases exhibited good anti-oxidation stability and oxidation synergism with Ni3Al matrix. The analysis shows that the Cr3C2 phase dissolved during welding, resulting in Cr entering into Ni3Al matrix, which promotes alpha-Al2O3 formation, and improves the oxidation resistance of the composite obviously. The oxidation rate of the Ni3Al alloy is two times greater than that of the composite in air. Good phase stability and chemical stability make Cr3C2/Ni3Al composite suitable for long-term service at 1000 degrees C.