摘要
采用真空非自耗电弧熔炼然后再真空自耗电弧熔炼的方法制备了Nb-Ti-Si-Cr-Hf-Al-B-Y超高温合金的母合金锭,分析了其在不同位置的组织组成及成分分布特点。发现母合金锭的组织主要由Nbss与(Nb,X)5Si3两相组成。在母合金锭的边缘部位,组织主要由(Nbss+(Nb,X)5Si3)共晶团组成,此外还有少量的Nbss枝晶;但在母合金锭的中央部位,组织由初生(Nb,X)5Si3块或板条以及(Nbss+(Nb,X)5Si3)共晶团组成。母合金锭中的成分分布特点为Si含量由锭边缘向中央逐渐升高,而由锭下部到上部逐渐降低;Ti含量的变化则为由锭边缘向中央,由锭下部到上部逐渐减少。
A master alloy ingot of Nb-Ti-Si-Cr-Hf-Al-B-Y ultrahigh temperature alloy was prepared by firstly vacuum non-consumable arc melting and then vacuum consumable arc melting.The microstructure and compositional distribution in the master alloy ingot was analyzed.It has been found that the microstructure of the ingot was mainly composed of Nbss(Nb solid solution) and(Nb,X)5Si3(where X represents Ti,Hf and Cr elements) phases.The microstructure on the edge of the ingot was mostly consisted of Nbss+(Nb,X)5Si3 eutectic colonies,but there was very small amount of primary Nbss dendrites at some local places.However,the microstructure was composed of big primary(Nb,X)5Si3 blocks or plates and Nbss+(Nb,X)5Si3 eutectic colonies in the central part of the ingot.The compositional distribution was not uniform in the master alloy ingot. The Si content increased from the edge part to the central part of the ingot,but decreased from the lower part to the upper part of the ingot.The Ti content was decreasing both from the edge part to the central part and from the lower part to the upper part of the ingot.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2007年第z1期164-168,共5页
Journal of Materials Engineering
基金
国家自然科学基金(50671081)
教育部新世纪优秀人才支持计划资助项目
关键词
铌硅化物基超高温合金
组织形成
成分分布
电弧熔炼
Nb silicide based ultrahigh temperature alloy
microstructural formation
compositional distribution
arc melting
