瞬间液相扩散焊与钎焊主要特点之异同

Similarities and Differences in Main Characteristics Between Transient Liquid Phase Bonding and Brazing Process

关键词:  瞬间液相扩散焊  钎焊  异同

Key words:  transient liquid phase bonding  brazing  similarities and difference

摘要:

从焊接进程、凝固、氧化物的破碎、中间层与钎料的区别、接头组成、脆性相的形成与消除、压力的作用、接头强化机理等方面总结分析了瞬间液相扩散焊与钎焊的区别。强调指出了下述关键点:(1)中间层的选取是获得两种不同焊接方法接头的首要前提;(2)在钎焊中侧重点是润湿性,它是保证接头获得一定强度的首要前提与主要手段;(3)在瞬间液相扩散焊过程中,除了润湿性之外,更为关注的是降熔元素的扩散。中间层中降熔元素向母材的持续扩散是TLP接合中液态区增宽、破碎氧化膜、等温凝固、均匀化现象的本质原因;降熔元素向母材的充分扩散及由此而出现的中间层成分的合理改变是TLP焊接成败的命脉。

Abstract:

The similarities and differences in main characteristics between transient liquid phase (TLP) bonding and brazing process are compared in the following aspects:bonding process,solidification,oxide disruption,interlayer and filler metal,constituent parts of joint,formation and disappearing of brittle phase,effects of pressure,mechanisms of strengthening joint.The following key points are pointed out especially.(1)Careful selection of interlayer is a precondition to get a TLP bonded joint or a brazed joint.(2)The wettablity of filler metal on base metal is the key point in brazing process,because it is the precondition and main approach to make joint strong.(3)A sufficient diffusion of melting point depressant (MPD) elements into base metal and a suitable change of composition of interlayer due to loss of MPD elements by diffusion are the vitals to get a successful TLP bonding,because the essential reason for liquid zone widening,oxide disruption,isothermal solidification and homogenization of bond region is the diffusion of MPD elements.