改造Ti-24Al-15Nb-1.5Mo/TC11双合金焊缝组织与增强连接界面性能的工艺

Craft of Improving Microstructure and Properties of Ti-24Al-15Nb-1.5Mo/TC11 Dual Alloy Welding Joints

研究近等温锻造+梯度热处理工艺对Ti-24Al-15Nb-1.5Mo/TC11双合金焊接接头的显微硬度变化、合金元素扩散趋势、显微组织特征和拉伸性能的影响。结果表明:近等温锻造+梯度热处理能使焊接接头得到强化。经近等温锻造和梯度热处理后焊缝熔合区形成的马氏体α′和α″相分解为α(α2)+β的平衡组织;TC11合金热影响区的魏氏组织转变为网篮组织;试样具有良好的500℃高温综合性能(σb:840MPa,δ:18.5%,ψ:65%)。

The effect of near isothermal forging and gradient heat treatment on the micro-hardness distribution, the trend of elements diffusion, the microstructure and tensile property have been investigated for the welding Ti-24Al-15Nb-1.5Mo/TC11 dual alloys joint. The results show that the joint can be strengthened through near isothermal forging and gradient heat treatment. During heat working, the martensite a＇ phase and a＂phase in fusion zone of joint are breaken up into a balance microstructure consisting of a （a2） phase ＋ βphase. The Widmanstatten structure changes into the basket weave structure in the alloy TC11 heat-affected zone of joint. In addition, the joint has excellent high temperature properties after near isothermal deformation and gradient heat treatment （σ, is 840 MPa, 6 is 18.5%, and is 65%）.