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通过液态金属冷却技术制备了名义成分为Ni-30.4Al-34Cr-4.3Mo-0.1Hf-0.05Ho(原子分数,%)的定向合金.定向凝固工艺消除了普通铸造合金中的初生Cr(Mo)相,获得了共晶组织.随抽拉速率从8 mm/min提高到15 mm/min,合金中的共晶胞尺寸从115μm减小到85μm,共晶胞间距变窄,胞间混乱区减少.与普通铸造相比,定向凝固工艺能提高该共晶合金的室温、高温拉伸强度,高温拉伸塑性以及室温断裂韧度,并且定向合金的上述力学性能随抽拉速率增大而增大.
A directional alloy with nominal composition of Ni-30.4Al-34Cr-4.3Mo-0.1Hf-0.05Ho (atomic fraction,%) was prepared by the liquid metal cooling technique.The directional solidification process eliminated the primary Cr (Mo) Phase, the eutectic structure was obtained.The eutectic cell size in the alloy decreased from 115μm to 85μm with increasing the drawing speed from 8mm / min to 15mm / min, the eutectic cell spacing became narrower and the interstitial cells were reduced Compared with ordinary casting, the directional solidification process can improve the room temperature, high temperature tensile strength, high temperature tensile ductility and room temperature fracture toughness of the eutectic alloy, and the mechanical properties of the oriented alloy increase with the increase of drawing rate .