多向等温锻造Ti-44Al-4Nb-1.5Cr-0.5Mo-0.1B-0.1Y合金高温压缩变形行为研究  

Study on High Temperature Compressive Deformation Behavior of Multi-directional Isothermally Forged Ti-44Al-4Nb-1.5Cr-0.5Mo-0.1B-0.1Y Alloy

作　　者：陶国强 祁广源 曲寿江[1] 沈军[1] Tao Guoqiang;Qi Guangyuan;Qu Shoujiang;Shen Jun(Tongji University,Shanghai 201804,China;Dalian Power Supply Company,Dalian 116000,China)

机构地区：[1]同济大学,上海201804 [2]大连供电公司,辽宁大连116000

出　　处：《钛工业进展》2018年第3期11-15,共5页Titanium Industry Progress

基　　金：国家自然科学基金联合重点基金项目(U1302275);国家自然科学基金青年科学基金项目(51305304);国家科技重大专项课题资助项目(2013ZX04011061)

摘　　要：采用扫描电子显微镜(SEM)/电子背散射衍射(EBSD)、透射电子显微镜(TEM)等技术,研究经二步等温锻造得到的Ti-44Al-4Nb-1.5Cr-0.5Mo-0.1B-0.1Y(原子分数)合金单向高温压缩变形行为,揭示该合金变形过程中的组织演变及其变形机理。研究结果表明,该合金中的α2相在等温锻造及随后的单向高温压缩过程中大部分转变为B2相和γ相;高温变形过程中γ相主要细化机理为动态再结晶,而B2相则为动态回复;孪生及其交互作用是重要的变形机理,孪晶界促进了非连续动态再结晶,从而有助于细化晶粒。Microstructural evolution and deformation mechanism of a two-step isothermally forged Ti-44Al-4Nb-1.5Cr-0.5Mo-0.1B-0.1Y(at.%)alloy were investigated during high temperature uniaxial compression,by using scanning electron microscopy(SEM)/electron backscattered diffraction(EBSD),and transmission electron microscopy(TEM).The results show that the most of theα2 phases transform into B2 andγphases after isothermal forging(ISF)and uniaxial high temperature compression.Dynamic recrystallization is the main refinement mechanism ofγphase,while B2 phase is dominated by dynamic recovery.Deformation twinning and twining interaction play an important role in the deformation mechanism of TiAl-based alloys and promote discontinuous dynamic recrystallization,hence lead to the refinement of microstructure.

关 键 词：TIAL基合金 等温锻造 动态再结晶 孪生 

分 类 号：TG146.23[一般工业技术—材料科学与工程]