摘要
通过对Ti-46Al-8Nb-2Mn-0.2B合金的铸态组织和经过α+γ双相区热处理后的组织进行光学和扫描电镜进行观察,发现原始铸态组织的γ相偏析处不是片层的晶界,而是片层穿越的区域.由于γ相偏析区域的Al含量比片层基体高,因此阻碍了后续回火过程中该偏析部位片层的分解.通过先得到近γ组织,然后经过α+γ双相区保温,最终得到晶粒为40μm的双态组织;但组织中有少量的β相没有得到消除.
The as-cast structure and microstructure obtained after heat-treatment in the α+γ field of a Ti- 46Al-8Nb-2Mn-0.2B alloy were studied. Optical and SEM observations show that the γ phase segregation region is not the grain boundary of the alloy but part of the α + γ lamella. The Al content at the γ phase segregation region is a little more than the α + γ lamella matrix, but it can play an important role in stabilizing the lamella and does harm to the break-up at the γ phase segregation region. By obtaining near γ microstructure firstly in the alloy and then heat-treating it in the middle region of the α + γ field, the duplex microstructure with a grain size of 40μm can be formed, but a little of β phase still exists.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
2007年第3期278-281,319,共5页
Journal of University of Science and Technology Beijing
基金
教育部新世纪优秀人才支持计划资助项目(No.NCET-04-01017)
关键词
TIAL合金
双态组织
热处理
偏析
TiAl alloys
duplex microstructure
heat-treatment
segregation