Characterization of Laser Brazed Joints Vis a Vis Conventional BIW Joining Methods 2021-26-0447

In recent years, there has been a rapid growing demand for laser brazing in the transportation industry for automotive-Body in White (BIW), steel sheet assembly. Implementation of laser brazing is aimed primarily to improve productivity, quality of joints and cost. Laser brazing works by filling the opening amongst two substrates by melting the filler wire with the help of laser beam (used as a heat source), whereas in conventional resistance spot welding, contacting metal surface points are joined by the heat obtained from resistance to electric current. BIW is essentially a welded metal structure which is meant to provide durability and crashworthiness to the vehicle and is conventionally assembled using resistance spot welding process. The BIW structure comprises of various steel grades having varying thicknesses, compositions, microstructures and mechanical properties. Laser brazing, as a joining method was introduced as an alternative to resistance spot welding for assembling certain BIW components (e.g., roof, BSO etc.). Physical and mechanical characterization is undertaken for typical vehicle laser brazed joints Vis a Vis resistance spot welding. The aim of this study is to determine the “method of testing, specimen geometry, mechanical characteristics (comprising of uniaxial tensile strength) and physical characteristics (length of brazement, joint clearance), of the concerned typical laser brazed joints” and creation of an “engineering specification with respect to “brazement and joint clearance, geometries” ”. The future scope of this work includes characterization of the corrosion and paintability behavior of the laser brazed joints.