l和Nd对Sn-Zn基无铅钎料波峰焊抗氧化性研究

race elements Al and Nd are added into Sn-9Zn alloys in order to improve the oxidation resistance of the solders in wave soldering. The surface of oxidation film and foamy mixture generated in wave soldering are examined by colorimetric analysis，optical microscopy and scanning electronic microscopy. The results show that Al element can significantly enhance the static oxidation resistance of Sn-9Zn solders and the addition of Nd improve the smoothness of Al oxidation film further. The foamy mixture is composed of matrix alloy, porosity and oxide which leads to the formation of oxygen-rich areas. When Al and Nd elements are added simultaneously, the content of oxide in foamy mixture decrease markedly since a layer of oxidation film is formed on the surface of solders which hinder the contact of solder fluid and oxygen.