SiC颗粒增强铝基复合材料的连接现状

Reviews on welding method of SiC particle reinforced aluminum matrix composites

SiC颗粒增强铝基复合材料因其具有成本低、耐磨性好、高比强度和比刚度、高谐振频率等优良的性能受到关注,但由于难于机械加工,特别是焊接性较差制约其在工程中的应用推广.文中通过对国内外SiC颗粒增强铝基复合材料的连接现状(焊接方法主要集中于熔化焊、扩散焊、搅拌摩擦焊和钎焊等)进行综述和评价.结果表明,SiC颗粒和Al基体的较大物理化学性能差异是影响该种复合材料焊接性的主要因素;当SiC颗粒体积分数低于35%时,目前已取得令人基本满意的焊接效果,已具有小批量生产的趋势;但当SiC颗粒体积分数大于35%时,特别是针对高体积分数(55%～75%)的复合材料而言,传统的熔化焊方法很难获得高质量的接头,因此选择合适的连接方法和特殊的焊料成分则成为该种材料的重要创新方向.

SiC particle reinforced aluminum matrix composites have been concerned because of excellent properties such as low cost,superb wear resistance,high specific strength,nice specific stiffness and outstanding high resonant frequency.However,the difficulty in mechanical processing,especially the poor weldability,has restricted its engineering application.This paper reviews the welding technology progress of SiCp/Al composites,including melting welding,diffusion welding,friction stir welding and brazing.The results show that the obviously different physical and chemical properties between SiC particles and Al matrix reduced the weldability of the Al matrix composites.When the volume fraction of SiC particles is below 35%,the welding joint is mostly adequate,even to the trend of small batch production.However,if the volume fraction of SiC particles is above 35%,especially 55%-75%for the composites with high volume fraction,it is difficult to obtain high quality joints by traditional fusion welding method.Therefore,it is an important innovation direction for suitable connection method and special filler.