Effect of Alloying Elements on Melting Point of Al-Si Based Brazing Filler Metal

In order to develop Al-Si based brazing filler metals with good technological properties and low melting point,Si,Cu,Ni and RE were added into the Al-Si based solder.Effect of the added elements on the melting point of Al-Si based solder was analyzed by orthogonal test.Melting point of 25 kinds alloys were tested by differential thermal analyzer.Microstructure and components were also analyzed by SEM and EDS.The results show that the added alloying elements all could bring down the melting point and the decrease degree from major to minor was Cu,Si,Ni and RE.Al-6.5%Si-25%Cu-2%Ni-0.3%RE alloy had the lowest melting point of 526.43 ℃.