铝制油冷器真空钎焊接头熔蚀行为研究

Research on Corrosion Behavior of Vacuum Brazing Joint of Aluminum Oil Cooler

对铝制油冷器进行真空钎焊实验,采用金相分析方法研究了钎焊接头的熔蚀行为,并进行了理论分析。结果表明:在设定钎焊温度630℃,实际钎焊温度627℃,保温时间4min时,铝制油冷器翅片与隔板T型接头圆角处发生严重的熔蚀行为,其实质是钎料和母材之间发生过分的相互作用,母材大量溶解进钎料中,被溶解的母材的位置被液态钎料冷却重凝出来的α-Al组织占据,温度越高,钎料体积越大,保温时间越长,越易发生熔蚀。

The corrosion behavior of vacuum brazing joint of aluminum oil coolers was studied by OM,and the analyses in theory were introduced.The results show that,when the set brazing temperature of furnace is 630 ℃,actual brazing temperature is 627 ℃,and brazing holding time is 4 min,the serious corrosion occurs at T-joints tooth fillet between the fin and the diaphragm.The corrosion results from the interaction between the base metal and the filler metals,that is the base metal dissolved in filler metals,and the location of dissolved base metal is occupied by α-Al.In addition,it is also found that the corrosion increases at high temperature,long holding time when brazing and the high volume of filler metals.