Semi-Solid State Joining of SSM Aluminum Alloys Using Brazing ZA27

Abstract

Semi-solid state joining of SSM A356 aluminum alloy under normal atmosphere using ZA27 as a filler was investigated. Localized semi-solid pool of ZA27 filler was created by an induction heating coil for butt joint of SSM A356. Then a stirrer was applied into the weld seam to stir the filler. The accurate control of semi-solid temperature during joining was measured. The effect of welding speed on physical and mechanical properties, macrostructure and microstructure was studied. The results showed that the weld microstructure was rosette globular structure. In addition, voids were found at the seam. The interface between base metal and filler exhibited sound bond. A decrease in welding speed resulted in a reduction in a number of voids presented in the structure. The best tensile strength and micro hardness of the joints were obtained from the optimum condition using rotation speed at 1,750 rpm and welding speed at 15 mm/min.