合金成分及熔炼工艺对多元铌基超高温合金组织的影响  

Effects of Compositions and Melting Processes on the Microstructure of Multicomponent Nb-Based Super-High Temperature Alloys

作　　者：郭海生[1] 郭喜平[1] 贾丽娜[1] 武兴君[1] 丁旭[1] 高丽梅[1] 任家松[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2008年第7期1299-1303,共5页Rare Metal Materials and 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

摘　　要：采用真空自耗电弧熔炼和真空非自耗电弧熔炼2种工艺熔炼了4种不同成分的多元铌基超高温合金,研究了合金成分及熔炼工艺对组织的影响规律。结果表明:4种成分的合金均由初生Nb基固溶体枝晶或初生(Nb,x)5Si3(x代表Ti,Cr和Hf元素)块和板条以及Nbss/(Nb,x)5Si3共晶团组成。随着Si含量的升高,组织中Nbss/(Nb,x)5Si3共晶团的含量增多且初生相也从Nbss枝晶转变为(Nb,x)5Si3块或板条。铌硅化物相为γ-(Nb,x)5Si3及β-(Nb,x)5Si3。大块或板条状硅化物内有微裂纹出现。Four batches of multicomponent Nb-based super-high temperature alloys with different compositions have been prepared by vacuum consumable arc-melting or vacuum non-consumable arc-melting. The effects of compositions and melting processes on the microstructure of multicomponent Nb-based super-high temperature alloys are studied. The results show that the four batches of alloys with different compositions are composed of the primary Nbss （Nb-based solid solution） dendrites, or the primary （Nb, x）5Si3 blocks and plates （x represents Ti, Hf and Cr elements） and the Nbss/（Nb, x）5Si3 eutectic clusters. With the increase of Si content, the amount of Nbss/（Nb, x）5Si3 eutectic clusters increases, and furthermore, the primary phase changes from the Nbss dendrites to the （Nb, x）5Si3 blocks and plates. The Nb silicides are in the forms of γ-（Nb, x）5Si3 and β-（Nb, x）5Si3. Some micro-cracks are observed in big Nb silicide blocks and plates for the four batches of alloy ingots.

关 键 词：多元铌基超高温合金 组织 电弧熔炼 β-Nb5Si3 

分 类 号：V250.2[一般工业技术—材料科学与工程]