超塑性TiAl基合金的显微组织特征  

Microstructural Characterization of a Superplastically Deformed TiAl-Based Alloy

作　　者：周科朝[1] 黄伯云[1] 曲选辉[1] 陈小群[1] 

机构地区：[1]中南工业大学,长沙410083

出　　处：《稀有金属材料与工程》1998年第6期336-339,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金!50371001

摘　　要：采用金相显微镜、扫描电镜和透射电镜，对超塑性拉伸变形后的Ti－33Al－3Cr－0．5Mo（质量分数）合金的显微组织进行了观察和分析。研究发现，TiAl基合金在超塑性变形过程中发生了动态再结晶现象，动态再结晶使晶粒显著细化。透射电镜观察结果表明，γ晶粒内有位错运动．位错运动导致γ晶粒内形成位错墙、位错网。这些显微组织特征与TiAl基合金的超塑性变形机理有着密切的关系。The microstructural evolution of a TiAl-based alloy is very different from those of the ordinary superplastic metals or alloys. The microstructure of a superplastically deformed Ti-33Al-3Cr-0. 5Mo (%) alloy has been observed and analyzed using optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It has been found that dynamic recrystallization occurs in superplastically deformed TiAl-based alloys resulting in extreme grain refinement. Furthermore, dislocation movement was found in γ grains, in which dislocation walls and nets were formed. In this way the relationship between microstructural evolution and the superplastic deformation mechanism is explained.

关 键 词：显微组织 超塑性变形 TIAL基合金 位错 动态再结晶 

分 类 号：TG146.2[一般工业技术—材料科学与工程]