我厂有一批银镉粉末合金电气接点,经长期使用,表面烧损,需堆焊修复。当采用银镉钎料堆焊修复时,由于镉在高温时“升华”,而使熔化金属“翻泡”,造成“蜂洞”。加之银基钎料中一般都含有一定量的锌,它在高温也会产生锌蒸气,使堆焊金属形成气孔。因此焊接时首先要控制被焊件的温度,阻止镉的升华。经过反复试验,采用比较合理的施焊工艺,取得很好效果。施焊工艺如下: 1、首先将堆焊表面清除污锈;2、基 I plant a number of silver-cadmium powder alloy electrical contacts, the long-term use, the surface burning loss, required surfacing repair. When using silver-cadmium solder surfacing repair, due to cadmium at high temperatures, “sublimation”, leaving the molten metal “bubble”, resulting in “beehive.” Coupled with the silver-based solder generally contains a certain amount of zinc, it will also produce zinc vapor at high temperatures, so that the formation of stomatal welding metal. Therefore, the first welding to be controlled by the welding temperature, to prevent the sublimation of cadmium. After repeated tests, the use of more reasonable welding process, and achieved good results. The welding process is as follows: 1, the first surface of the surfacing to clear the rust; 2, base