摘要
在ＴｉＡｌ合金中添加过渡族合金元素，观测了其微观组织和结构，测定了室温弯曲性能和高温氧化性能，研究了改善塑性及提高其高温氧化抗力的因素。试验结果表明，与单相γ－ＴｉＡｌ不同，添加过渡族元素Ｃｒ、Ｎｂ的Ｔｉ－４８Ａｌ－２Ｃｒ－２Ｎｂ钛铝化合物所形成的双相或等轴γ和α２／γ片层状双态组织，改善了脆性γ－ＴｉＡｌ合金的室温塑性，使弯曲强度达４９０ＭＰａ，弯曲挠度为０．３９ｍｍ；；大量层错带和变形孪晶的形成是室温变形的主要机制。另外，在高温下，钛铝化合物的表面由表及里形成了不易剥落的ＴｉＯ２、Ａｌ２Ｏ３及ＴｉＯ２＋Ａｌ２Ｏ３三层氧化层，连续。
Adding alloying elements of transition metals in titanium aluminid intermetallics and observing microstructure and measuring room temperature bending properties and high temperature oxidation resistance were investigated. Tests results show that differing from TiAl,because of forming two phase or duplex structure,considerable improvements in room temperature strength and room temperature ductility have been achieved by addingchromium and Niobium in Ti52Al48,i.e. bending strength to 490MPa and bending deflection to 0.39mm.Producing a large number of stacking bend and twins in defor mation are dominant micromechanisms of room temperature deformation. Otherwise,in elevated temperatare 900℃、18h,the surface oxide scale of three layers ( TiO 2,Al 2O 3 and TiO 2+Al 2O 3)from the surface inward were formed. A continuous and dense Al 2O 3 layers are important reasons of increasing oxidation resistance of the Ti 48Al 2Cr 2Nb titanium aluminid intermetallcs.
出处
《机械科学与技术》
CSCD
北大核心
1997年第2期291-294,共4页
Mechanical Science and Technology for Aerospace Engineering
基金
航空科学基金
