一、前言金属与合金的熔化焊接是简便而有效的热加工工艺之一,因而在机械制造中得到了越来越广泛地应用。众所周知,熔化焊过程实际上是小型的局部冶金过程,在焊接热源作用下使填充材料和被焊金属熔化,通过熔融金属的凝固 I. Introduction Melting and welding of metals and alloys is one of the simple and effective thermal processing techniques and has been applied more and more widely in machinery manufacturing. It is well known that the fusion welding process is actually a small local metallurgical process that melts the filler material and the metal to be welded under the action of the welding heat source and passes through the solidification of the molten metal