真空钎焊中晕环现象的研究

通过试验研究发现,晕环是由于Cu,Ag,Sn,Mn和Au等几种元素导先钎料整体沿晶界或毛细磨痕润湿母材的结果,从而提高钎料的润湿性。液态钎料与母材的性能以及在钎焊温度下相互作用情况是影响晕环形成的主要因素。

Research on the Phenomena of Wetting Halo in Vacuum Brazing

The experimental results show that there are three different patterns of liquid filler metal wetting edge in vaccum brazing, namely, the liquid filler metal spreads and wets along the surface grain boundary of the base metal in all directions ;The liquid filler metal spreads and wets along the surface capillary grinding groove of base metal in all directions; The liquid filler metal spreads and wets evenly in all directions. The first two patterns are often accompanied by wetting halo in wetting edge. The color of wetting halo is different from the filler metal. The wetting halo is different from the filler metal. The wetting halo is caused by the prior spreading of some elements in the filler metal a-long the surface grain boundary or capillary grinding groove of base metal and improves the wettability of the filler metal. Only when the filler metal containning the elements of Cu.Mn.Sn.Ag and Au spreads and wets along the surface of the base metal.a wetting halo can he formed.The formation of wetting halo depends mainly on the property and interaction of the filler metal and base metal in brazing temperature.