Mechanical Properties and Microstructural Characterisation of Dissimilar Laser Welded Joints of Titanium Grade 2 With AA5052 Alloys

Abstract

The joining of titanium alloy with aluminium alloy could have a major application in the field of aerospace and automobile industry where high strength and low weight are desirable. Dissimilar materials joining can be described as combining materials that are more difficult to join than two pieces of the same materials (or) alloys with minor differences in chemical composition. Nowadays, many dissimilar materials can be joined successfully with appropriate joining process like high energy welding process such as electron beam welding and laser beam welding. In this work, Titanium grade-2 alloy and Aluminium AA5052 alloys are selected with suitable process parameters of laser power, welding speed and torch angle using laser welding process. The four different combinations of laser welded joints are performed based on parameters of machine availability and dimensions of the work piece. The tensile tests are carried out on the welded samples to evaluate the maximum tensile strength of the welded joints. Microstructural studies are carried out on the welded samples for finding the formation of grain structure of the joints. The SEM analysis are carried out on the fractured surfaces of the dissimilar joint for the welded joint which has superior tensile strength and least tensile strength. It is concluded that the dissimilar combination of 120.1 MPa with laser power 1.5 kW, welding speed 10 mm/sec and torch angle 45 degrees to the titanium side gave the superior tensile strength compared to the other welded joints.