Green and energy-efficient manufacturing processes offer sustainable production of engineering products utilizing effectively and efficiently all resources with the little impact on the environment.

Among the various fabrication processes, fusion welding is one of the major production processes applied to fabricate small components to huge intricate structures.

As fusion welding consumables such as filler materials, fluxes, shielding gases, etc. produce dangerous fume plumes, fusion welding has severe influence on human health as well as environment.

Friction Stir welding (FSW) being a cold-welding, solid-state, more-environmentally friendly process has been established as a green, energy efficient, and sustainable process for joining non-ferrous and ferrous materials.

Inconel 718 alloy finds extensive applications in aerospace and power industries due to its significant high temperature properties. Though recent developments on consumables and fusion welding techniques enabled its weldablity more benefits will be reaped by welding those Inconel super alloys by FSW.

It is a great challenge to join Inconel 718 by FSW due to its high strength and hardness and the requirement of very hard and wear resistance FSW tool. In this paper, details about FSW of nickel based super alloy 718 using polycrystalline cubic boron nitride FSW tool for joining 2.1 mm thick sheets are provided.

The friction stir welded sheet was heat treated and the metallurgical and mechanical properties of the weldment were evaluated. The ultimate tensile strength of the heat-treated joint was estimated to be 1212 MPa which is equal to the base Inconel 718 alloy.

The stir zone had finer grains compared to the base metal and the weldment contained gamma matrix with various carbides and laves phases contributing to the strength of the weld.

This article is shared by N. Murugan and S. G. K. Manikandan.