Evolution of microstructure and mechanical characteristics of friction stir welded ultrafine‐grained aluminum alloy 6082

Abstract

Bulk production of ultrafine‐grained material is in great demand presently. Ultrafine‐grained material can be synthesized using accumulative roll bonding, which is a prominent severe plastic deformation technique to develop such materials in bulk. There are further challenges in the fabrication of ultrafine‐grained material. Friction stir welding is a potential technique to join the ultrafine‐grained material while maintaining its mechanical and microstructural characteristics stability as no fusion is required. The present research work demonstrates the microstructural and mechanical characteristics of various welding zone after friction stir welding of ultrafine‐grained aluminum alloy 6082. The microstructural features were examined using optical microscopy and the electron back‐scattered diffraction technique. The variation in mechanical characteristics was observed using tensile and microhardness tests. The fractography of tensile specimens was studied to identify the mode of failure. The present study demonstrates the viability of friction stir welding to join ultrafine‐grained aluminum alloy 6082 developed by accumulative roll bonding. The ultrafine grain size of 0.52 μm was achieved after four accumulative roll bonding cycles. The microhardness of accumulative roll bonding processed samples and the tensile strength of the weld joint were increased about two times and 1.6 times respectively compared to the annealed sample.

Fabrication of wear resistant nanocomposite and its mechanical properties: A step towards sustainability

“…The mechanical polishing of the samples includes the surface finish using emery paper varied grit sizes from P600 to P2000 followed by cloth polishing using alumina powder of 5 μm particle size. After final polishing, etching was employed to reveal the microstructure of the samples using Keller's etchant (15 ml of hydrochloric acid, 25 ml of nitric acid, 10 ml of hydrofluoric acid and 50 ml of distilled water) [24]. The microstructure was further investigated using electron back scattered diffraction analysis (Model: FEI Quanta 3D FEG).…”