合金化对定向凝固Ti-AI-Nb合金微观结构与力学性能的影响

摘要

Cr- and Mo- doped high-Nb containing Ti-Al alloys were fabricated using directional solidification process. Their microstructures and mechanical properties were examined. Results showed that both the two alloys displayed basket-weave type microstructures. The laths in Ti-16Al-12Nb-3Cr-lMo tended to be inclined with a smaller angle to the withdrawal direction than Ti-16Al-12Nb alloy although the limited thermal gradient and comparatively high withdrawal velocity were employed. Remarkable enhancement in strength and ductility was achieved at room temperature and 650℃.%采用定向凝固方法制备了Cr/Mo微合金化高Nb Ti-Al合金,并考察了其微观结构和力学性能.结果表明,两种合金都呈现出层片状微观组织.尽管温度梯度受限,抽拉速度较高,但与Ti-16A1-12Nb相比,Ti-16A1-12Nb-3Cr-1Mo合金中的片层倾向于与抽拉方向呈更小角度生长,在室温和650℃时的拉伸强度和塑性均呈显著增加.