采用Cu中间层的Ti6242钛合金接触反应钎焊

Contact reactive brazing of Ti 6242 alloy using Cu interlayer

用Cu做中间层实现Ti6242钛合金的接触反应钎焊,通过扫描电镜和拉伸试验对接头界面组织和力学性能进行表征。结果表明:在940℃保温2 min即可使中间层与母材充分反应,完全转变成Ti-Cu共晶。随保温时间延长,Cu不断向基体扩散,保温10 min组织转变为Ti_(2)Cu金属间化合物和共析组织;保温至20 min时,主要由α-Ti和少量共析反应β-Ti分解产生的Ti_(2)Cu组成;保温20 min得到的接头强度与母材一致,实现了与母材的等强连接。

The interfacial microstructure and mechanical properties of contact reactive brazed Ti6242 joint using Cu interlayer were investigated with the aid of scanning electron microscopy and tensile test.The results show that exposure at 940℃for 2 min promotes intensive metallurgical reaction between Cu interlayer and Ti6242 substrate,leading to the formation of Ti-Cu eutectic liquid.Prolonged bonding duration results progressive diffusion of Cu towards substrate,and the microstructure changes into Ti_(2)Cu and eutectoid structure when bonded for 10 min.Further prolonging bonding duration to 20 min results in joint primarily composed ofα-Ti and tiny Ti_(2)Cu decomposed fromβ-Ti via eutectoid transformation.Bonding strength comparable with substrate properties is obtained in the joint bonded for 20 min,which realize the equal strength connection with the base metal.