摘要
进行了常温和550℃下Ti-43Al-8.5V-Y合金的静态拉伸试验,分析了β相的引入对γ-TiAl基合金力学性能的影响。结果表明:V元素促使球状α_2相和条带状β相的形成,β相提高了材料的高温塑性同时降低了材料强度;Ti-43Al-8.5V-Y合金常温拉伸断裂的主要形式是准解理断裂,存在部分穿晶断裂,晶间的β相断裂是合金破坏的主要原因;孔洞的增殖以及与穿层裂纹的相互连通是该合金高温断裂的主要原因。
The test of Ti-43 Al-8.5 V-Y alloy's static tensile at 550℃ and room temperature was conducted respectively and the β phase influence on the γ-TiAl alloy mechanical properties was analyzed to show that the V elements can prompt formation of both the spherical α_2 phase and the stripped β phase; and the β phase increases the plasticity of the material while reducing the strength of the material. Experimental results show that, the main form of the constant temperature tensile fracture of Ti-43 Al-8.5 V-Y alloy is the quasi-cleavage fracture,β phase fracture is the main reason for the failure of the alloy. The hole proliferation and mutually connecting with each other through layers of crack is the main characteristics of high temperature tensile fracture of the alloy.
引文
[1] Carneiro T,Kim Y W.Evaluation of Ingots and Alpha-Extrusions of Gamma Alloys Based on Ti-45Al-6Nb[J].Intermetallics,2005,13(9):1000~1007.
[2] Lorenz U,Appel F,Wagner R.Thermally Activated Deformation Mechanisms in Micro-Alloyed Two-Phase Titanium Amminide Alloys[J].Materials Science & Engineering A,1997,233(8):1~14.
[3] Chan K S.Gammer Titanium Aluminades[M].Warrendale:TMS,1995:835.
[4] 曹睿.γ-TiAl 合金破坏与断裂机理研究[D].兰州:兰州理工大学,2006.
[5] Oh J,Pyo S G,Lee S.Fabrication of Multilayered Titanium Aluminide Sheets by Self-Propagating High-Temperature Synthesis Reaction Using Hot Rolling and Heat Treatment[J].Material Science,2003,(38):3647~3651.
[6] 闫茹,许正芳,林均品,等.高铌TiAl合金双态组织室温断裂行为研究[J].稀有金属材料与工程,2010,39(6):1041~1044.
[7] 孔凡涛,陈玉勇,韩杰才,等.钇对Ti-43Al-9V合金组织性能的影响[J].稀有金属,2004,28(1):75~77.
[8] 张永光,韩亚芳,陈国良,等.金属间化合物结构材料[M].北京:科学出版社,2001.
[9] 贺跃辉,黄伯云,周科朝,等.TiAl基合金显微组织对高温拉伸力学性能的影响[J].中国有色金属学报,1997,7(1):75~79.