A study on influence of MIG brazing parameters on microstructure and mechanical properties in joining of Al to AHSS for applications in automobile industry

Abstract

The aim of this research was to study on influence of MIG brazing parameters on microstructure and mechanical properties in joining of Al to AHSS. The brazing variables investigated in this study encompassed brazing speed, brazing current, filler metal feed rate, torch-plate distance, torch angle. The improvement of the joining process was accomplished using optimal brazing conditions obtained from statistics analysis. Results showed that, the optimal brazing parameters to maximize the mechanical properties were identified by using Taguchi method. From this investigation, it is found that the joints fabricated with the brazing speed of 500 mm/min, brazing current of 25 A, filler metal feed rate of 6.0 m/min, torch-plate distance of 1 mm, and torch angle of 90 ๐ the maximum shear strength of 68.40 MPa. In this study, the possible reaction products at the interface were confirmed using SEM, EDS and XRD analysis. During brazing, intermetallic grains formed at the filler alloy. An intermetallic compound layer composed of FeAl3Si2 was formed at the interface of the advanced high-strength steels and filler metal.