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采用真空自耗电弧熔炼法制备了Nb-Ti-Cr-Si基超高温合金合金锭,测试了其室温力学性能。结果表明:合金锭各位置处的成分除Cr元素外分布比较均匀,Cr元素从锭边缘到中心部分呈现减少的趋势。合金的显微组织主要由初生Nbss,呈片层状或花瓣状的Nbss/(Nb,X)5Si3共晶组织及细小的Nbss/Cr2Nb共晶团组成,但在合金锭顶部中央处还出现了少量的块状(Nb,X)3Si。随着离锭边缘距离的增加,初生Nbss枝晶杆由细变粗,Nbss/(Nb,X)5Si3共晶组织的定向效果逐渐消失,但Nbss/Cr2Nb共晶团体积分数有减小的趋势。经过多元合金化的Nb-Ti-Cr-Si基合金室温的抗拉强度为378.7MPa,室温断裂韧性为13.4MPa·m1/2。室温拉伸和断裂韧性试样的失效模式均为脆性准解理断裂。
Nb-Ti-Cr-Si based superalloy ingot was prepared by vacuum consumable arc melting method and its room temperature mechanical properties were tested. The results show that the composition of alloying elements is distributed more evenly than the Cr element, and the Cr content tends to decrease from the ingot edge to the center part. The microstructure of the alloy is mainly composed of primary Nbss, lamellar or petal-shaped Nbss / (Nb, X) 5Si3 eutectic and fine Nbss / Cr2Nb eutectic, but also appears in the center of the top of the alloy ingot A small amount of massive (Nb, X) 3Si. The orientation of Nbss / (Nb, X) 5Si3 eutectic gradually disappears with the increase of the distance from the ingot edge, but the volume fraction of Nbss / Cr2Nb eutectic decreases . After multivariate alloying Nb-Ti-Cr-Si-based alloys at room temperature tensile strength of 378.7MPa, room temperature fracture toughness of 13.4MPa · m1 / 2. Failure modes of tensile and fracture toughness specimens at room temperature are all brittle quasi-cleavage fracture.