The Influence of Niobium on the Interdiffusion Coefficients in α2 and γ of TiAl Alloys
Interdiffusion coefficients in α2-Ti3Al and γ-TiAl of conventional TiAl and TiAl-8Nb alloy were measured at the temperature ranging from 1273K to 1523K.Single-phase diffusion couples were employed,and the concentration profiles of Al after annealing were measured by an electron probe microanalyzer (EPMA),and the interdiffusion coefficients were calculated according to the Boltzmann-Matano method.The results showed that there was no significant concentration dependence of interdiffusion coefficients for all the alloys with various phases,and the values of interdiffusion coefficients covered three orders of magnitude (E-17-E-14) with the increase of temperature according to Arrhenius law.In α2-Ti3Al and γ-TiAl phase of conventional TiAl alloys,the pre-exponential factor and activation enthalpy were D0=3.95×10-5m2s-1,Q=276KJmol-1 ; D0=7.26×10-5m2s-1,Q=275KJmol-1 respectively.The pre-exponential factor and activation enthalpy were D0=4.54×10-6m2s-1,Q=244KJmol-1 in γ-TiAl phase of TiAl-8Nb alloys.However,the temperature dependence of interdiffusion coefficients in α2-Ti3Al of TiAl-8Nb alloys did not follow Arrhenius laws very well.With the addition of Nb,the interdiffusion coefficients increased significantly in α2-Ti3Al,but changed slightly in γ-TiAl at high temperature.
TiAl-8Nb alloy Interdiffusion coefficients Diffusion couple
Dongdong Han Xiangjun Xu Laiqi Zhang Yongfeng Liang Junpin Lin
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
国际会议
the Chinese Materials Congress 2012(2012年中国材料大会(CMC2012))
太原
英文
85-92
2012-07-13（万方平台首次上网日期，不代表论文的发表时间）