Effect of Transverse Magnetic Field On Microstructure And Mechanical Properties of Ti-6Al-4V Manufactured By Laser-MIG Hybrid Welding
Abstract In this paper, the external transverse magnetic field is used to assist the laser-MIG hybrid welding for Ti-6Al-4V (TC4). The microstructure and mechanical properties such as microhardness and tensile properties of the weld joints under 24 mT external magnetic field (EMF) and the referring weld joint without EMF are investigated and discussed. Results show that transfer layer (TL) performs the lowest microhardness in the weld seam and tensile specimens fail in this area for the referring weld joint without EMF, which indicates the TL is the weakest zone in the weld seam. The mechanical properties of weld seam improve significantly under 24 mT EMF, which average microhardness in TL increases 9.3% and failure stress of tensile specimens improve by 16.7%, whilst a mixed fracture mode is operative in the fracture surfaces. The research reveals the elementary microstructure of TC4 laser-MIG hybrid welding is in correlation to welding heat input under the influence of EMF.