Effect of high temperature aging on
microstructure and mechanical properties
of a directionally solidified Ni3Al
base alloy IC6A
microstructure and mechanical properties
of a directionally solidified Ni3Al
base alloy IC6A
(Beijing Institute of Aeronautical Materials，Beijing 100095, China)
Abstract: The effect of aging at 950℃ for up to 2000h on microstructure and mechanical properties of alloy IC6A was investigated with scanning electron microscopy(SEM), transmission electron microscopy(TEM) and energy dispersive spectroscopy(EDS) of electron probe micro-analyzer(EPMA). The results show that Ni3Y and Mo1.24Ni0.76 precipitated in the interdendritic area due to the addition of yttrium have no obvious change during high temperature aging. A needle like or rod like phase named Y-NiMo precipitated after aging for about 200h. The a mount and size of the Y-NiMo phases increase with the increase of aging time, which is similar with that in alloy IC6. The ultimate tensile strength at room temperature and stress rupture life under 1100℃, 90MPa of alloy IC6A have no obvious change before aging for 1000h and decrease obviously with increasing aging time after aging for 1000h. The yield strength of alloy IC6A at room temperature decreases obviously after aging for 500h and however, has no obvious change during further aging.
Key words: nickel aluminide; mechanical property; microstructure