Tungsten inert gas(TIG) welding-brazing technology using Mg-based filler was developed to join AZ31 B Mg alloy to TC4 Ti alloy in a lap configuration.The results indicate that robust joints can be obtained with welding current in the range of 60-70 A.The joint interface was found to be likely composed of Mg-Ti diffusion reaction layer accompanied with Mg_(17)Al_(12) precipitate phase,indicating that metallurgical joining was achieved.The optimized joint with average tensile-shear strength of 190 N/mm^2 was obtained and fracture occurred at the Ti/fusion zone interfacial layer during tensile test.Moreover,the fracture surface was characterized by equiaxed dimple patterns accompanied with a few lamellar tearing.Finally,finite element modeling(FEM) numerical simulation was developed to analyze the distribution characteristics of the temperature field of joints.
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