基于TC4/Ni杜瓦冷指焊缝微观组织及接头结构的研究

Welding Microstructure and Joint Structure Design of the TC4/Ni Dewar Cold Finger

针对微型节流制冷型红外焦平面探测器杜瓦冷指,选取TC4/Ni的钎焊形式,从钎焊方法和钎料类型的焊缝微观组织以及接头结构设计的可靠性等方面对TC4/Ni的钎焊工艺进行了研究。结果表明,结合应力、形变和降温时间仿真以及防锈蚀分析结果,研究TC4/Ni冷指端面结构钎焊工艺具有一定工程实用意义;并通过正交试验确定了高温真空钎焊+AgCu28钎料组合的较佳工艺方案,满足对控制元素偏析和减少焊接脆性相生成的目的;同时综合考虑钎透率、充耐压试验及剪切强度测试的结果,确定锥形焊缝为较佳焊接结构。

The brazing process of TC4/Ni for a Dewar cold finger with a miniature Joule–Thomson-cooled infrared focal plane detector was selected,and the brazing process of TC4/Ni was investigated based on the microstructure of the brazing method and solder type and the reliability of the joint structure.The results show that research on the brazing process of the TC4/Ni cold finger end-face structure has practical significance in engineering by combining the simulation results of stress,deformation,and cooling time with the analysis results of rust prevention and corrosion.Through an orthogonal test,an improved process scheme of the hightemperature vacuum brazing+AgCu28 brazing filler metal combination was determined,which could control element segregation and reduce the formation of the welding brittle phase.Based on the penetration rate,stamping,high-voltage holding,and shear strength tests,the conical weld was the best welding structure.