摘要
采用真空非自耗电弧熔炼法制备了Nb-Ti-Si基共晶自生复合材料的母合金锭,分别于1300,1400,1500和1600℃保温50小时对其进行了均匀化处理,然后于1100℃保温50小时进行了时效处理。热处理后的组织主要由Nbss和(Nb,X)5Si3(X代表Ti,Cr和Hf元素)组成,但经1600℃/50h和1600℃/50h+1100℃/50h热处理后的组织中出现了HfO2。热处理后,Nbss的晶格常数较电弧熔炼态的有所升高,Ti,Cr和Al仍然倾向于固溶在Nbss中,而Hf则倾向于固溶在硅化物中。随着热处理温度的升高,Cr,Ti和Al在Nbss和大块硅化物(Nb,X)5Si3中的分配比降低,而Hf的则略有升高。
The master alloy ingot of Nb-Ti-Si based eutectic in situ composites was prepared by vacuum nonconsumable arc melting.The coupons were homogenized at 1300,1400,1500 and 1600℃ for 50 hours respectively,and then aged at 1100℃ for 50 hours.The heat-treated microstructures were still composed of Nbss and(Nb,X)5Si3(X represents Ti,Hf and Cr elements).But after heat treatments at both 1600℃/50h and 1600℃/50h+1100℃/50h,HfO2 was found in the microstructure.After high temperature heat treatments,the lattice parameter of the bcc Nbss phase increased,Ti,Cr and Al elements still solutioned in Nbss preferentially,while Hf solutioned in silicides dominantly.Furthermore,the partitioning ratios of Cr,Ti and Al elements decreased,while that of Hf increased respectively with increase of the heat treatment temperatures.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2007年第z1期264-269,共6页
Journal of Materials Engineering
基金
国家自然科学基金(50671081)
西北工业大学博士论文创新基金(CX200605)资助
