Experimental investigations and effect of parameters on friction welded AISI 304 and Invar alloys

Abstract

ABSTRACT It is challenging to achieve sound weld quality between dissimilar materials such as AISI 304 and Invar alloys with the help of the fusion welding process due to various weld defects like slag inclusion and misalignment. In current work, Invar alloys and AISI 304 material is welded with 12 mm diameter and 70 mm length on a commercial friction welding machine. Taguchi L9 orthogonal design is utilised for experiments, and an optimised parameter combination is identified. Machining parameters such as friction rotation RPM − 1100,1300,1500 rpm, frictional pressure 33,43,53 MPa, and burn-off length 4,5,6 mm are selected for the experiments. Forge pressure is not applied in experimental tests, and the tensile strength of the weld joint is evaluated for comparison. The findings revealed that the lower friction pressure up to 43 MPa resulted in higher tensile strength up to 517 MPa and refined grains in the microstructure. The higher friction pressure resulted in lower tensile strength due to non-homogeneous temperature distribution at the weld interface. The burn-off length shows significant effects on tensile strength results beyond 5 mm. The findings demonstratedthat the process could join dissimilar materials with enhanced mechanical properties.