T2-304在空间环模设备中的钎焊密封工艺

Soldering and Sealing Process of T2-304 in Space Environment Simulation Equipment

针对空间环模设备中由于热沉与真空容器之间安装间隙过大导致其钎焊密封可靠性差的问题,采取焊前去除母材及钎料表层的氧化层,选择含银量45%的BAg45CuZn共晶钎料,使用外焰温度900℃左右的焊接热源,选用壁厚较大的热沉铜管和不锈钢管,通过焊接辅助件将焊接缝隙控制在0.1~0.2mm,将焊接加热时间控制在30s的工艺进行不锈钢管和铜管的钎焊密封,焊接试验效果良好,焊缝可靠。对焊缝进行低温-186℃、高温120℃的高低温循环冲击之后进行氦质谱仪检漏,检漏数据表明焊缝密封性能满足设备使用需求。

In order to solve the problem of poor reliability of brazing seal in space environment simulation equipment due to the large installation gap between heat sink and vacuum container,the following methods were adopted.Remove the oxide layer of base metal and solder surface before welding.BAg45CuZn eutectic solder with 45%silver content is selected.The welding heat source with external flame temperature of about 900℃is used.Heat sink copper pipe and stainless steel pipe with larger wall thickness are selected.The welding gap is controlled in 0.1mm to 0.2mm by welding auxiliary parts.The welding heating time is controlled in 30s.After brazing and sealing of stainless steel pipe and copper pipe with the above processes,the welding test results are good and the welding seam is reliable.Leak detection is carried out by helium mass spectrometer after cyclic impact at low temperature of-186℃and high temperature of 120℃on the weld.The leak detection data prove that the sealing performance of the weld meets the use requirements of the equipment.