TC21钛合金扩散连接接头的微观组织及界面质量

在780～980℃的温度下对TC21钛合金进行5～90min的扩散连接,研究接头的界面结合率、变形率、微观组织及微观硬度。结果表明,在连接温度为880℃、连接时间为15～30min的情况下,可以获得高质量的连接接头。接头的微观硬度随着连接温度的升高而增加,并在连接时间达到90min时取得峰值（HV367）。在连接温度为780~880℃、930℃和980℃时,分别观察到了全等轴组织、双态组织和全层片组织。α相的体积分数随着温度的升高和时间的延长而增加,并在880℃、60min时取得极值。

Microstructures and interfacial quality of diffusion bonded TC21 titanium alloy joints

Diffusion bonding of TC21 titanium alloy was carried out at temperature ranging from 780 ℃ to 980 ℃ for 5-90 min.The interfacial bonding ratio,deformation ratio,microstructures and microhardness of the diffusion bonded joints were investigated.Results show that joints with high bonding quality can be obtained when bonded at 880 ℃ for 15？30 min.The microhardness increases with increasing the bonding temperature,while it has a peak value（HV367） when bonding time is prolonged up to 90 min.Fully equiaxed microstructures,bi-modal microstructures and fully lamellar microstructures were observed when bonded in temperature range of 780-880 ℃,at 930 ℃ or 980 ℃,respectively.The volume fraction of α phase first increases and achieves the maximum when bonded at 880 ℃ for 60 min,and then descended.