采用复合钎料加压钎焊70%SiCp/Al复合材料

Pressure brazing of 70%SiCp/Al composites using composite fillers

采用机械球磨的方法制备了Al-Si-xSiC(x为体积分数)复合钎料,采用复合钎料实现了70%SiCp/Al复合材料的加压钎焊连接.利用SEM和EDS确定了钎缝是由α-Al,Si,SiC,Al2O3等相组成.结果表明,在压力作用下SiC颗粒被固定在钎缝区而使得钎缝区的组织类似于复合材料,钎缝中一定的SiC颗粒可以缓解母材与金属钎料之间的热膨胀系数之差,从而减小了焊接残余应力,可以提高接头的强度,而钎焊施加一定的压力则可促进钎料与SiC颗粒的润湿性.工艺适当时,接头最高强度达到125.7 MPa.

The Al-Si-xSiC(x is the volume fraction)composite fillers were prepared by mechanical ball-milling method,in order to achieve a connection of 70%SiCp/Al composites using pressure brazing.The joints are composed ofα-Al,Si,SiC,Al2O3 and other phase identified by SEM and EDS.The results showed that SiC particles are pinned in the seam which is similar to composites under pressure.Difference of coefficient of thermal expansion between the base metal and the fillers can be alleviated by certain SiC particles in the seam,thereby welding residual stress was reduced,and the strength of the joint was enhanced.In addition,the wetting of fillers and SiC particles can be promoted by a certain pressure during brazing.