Ti-22Al-20Nb-7Ta合金的显微组织和力学性能研究  

STUDY ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Ti-22Al-20Nb-7Ta INTERMETALLIC ALLOY

作　　者：毛勇[1] 李世琼[1] 张建伟[1] 彭继华[2] 邹敦叙[1] 仲增墉[1] 

机构地区：[1]北京钢铁研究总院高温材料研究所 [2]西南交通大学应用力学系,成都610031

出　　处：《金属学报》2000年第2期135-140,共6页Acta Metallurgica Sinica

基　　金：国家863计划资助!715-011-0121

摘　　要：研究了Ｔｉ－２２Ａｌ－２０Ｎｂ－７Ｔａ合金的显微组织和力学性能，为优化合金的塑性（特别是室温塑性）和强度，采用了多种热机械处理（ＴＭＰ）工艺．结果表明，合金显微组织与热机械处理工艺密切相关．通过热机械处理可有效地控制合金中α_２，Ｏ和Ｂ２相的形貌，分布状况及相对含量．进而获得了具有高的室温及高温屈服强度和优良塑性的Ｏ相合金，在（α_２＋Ｂ２＋Ｏ）和（Ｏ＋Ｂ２）相区热变形及在（Ｏ＋Ｂ２）相区的固溶和时效处理获得的三相复合显微组织具有最佳的力学性能．Ｔｉ－２２Ａｌ－２０Ｎｂ－７Ｔａ合金的室温屈服强度σ０．２达１２００ＭＰａ，延伸率达９．８％，６５０℃ 下σ０．２亦达９７０ＭＰａ，延伸率达１４％。Microstructure and mechanical properties of Ti-22Al-20Nb-7Ta intermetallic alloy have been studied. In order to optimize ductility and strength of the orthorhombic alloy, various thermome- chanical processing (TMP) were performed. The results indicate that the microstructures of the alloy are strongly dependent on TMP. The morphologies, sizes and volume fractions of or2, O and B2 phases in the alloy are controlled well through the optimized TMP. The O-phase alloys in Ta-Al-Nb-Ta system have a good combination of high tensile yield strength and good ductility. The duplex Omicrostructure with α2, O and B2 phases, deforming in (α2+B2+O) or (O+B2) phases field and treating in O+B2 phase field, possesses the highest tensile properties. The yield strengths of Ti-22Al-20Nb-7Ta alloy are 1200 MPa and 970 MPa, and the elongations are 9.8% and 14% at room temperature and 650 ℃ respectively.

关 键 词：热机械处理 显微组织 力学性能 钛合金 

分 类 号：TG146.23[一般工业技术—材料科学与工程]