Influence of Joint Configuration on Linear Friction Welded Ti-6Al-4V Alloy Joints

Abstract

Ti-6Al-4V alloy is a unique material for structural applications of aerospace industry for the excellent strength and lightweight. The fusion welding of this Titanium alloy resulted severe residual stress formation and coarser grains in the fusion zone. To overcome these problems, a solid state linear friction welding (LFW) is a emerge technique to joining of blade and disk assembly in the next generation aero engines. The plastic deformation followed by forging action resulted finer grain structures in welded regions. This investigation elaborated mechanical behavior and microstructural characteristics of linear friction welded joints. The welding parameters established by statistical response surface methodology. The fabricated joints yielded maximum tensile strength and joint efficiency of 1011 MPa and 98%. The lower microhardness recorded in the thermo mechanical affected zone (TMAZ) among the weld cross section. The weld nugget microstructure composed of equiaxed grain structure. The fracture surface revealed that joints failed under ductile mode. The result concluded that the weld failure mainly due to grain coarsening subsequent deformation leads to weld failure in the LFW joint.