Mechanical and microstructural characteristics of AA6082 using thermal equal channel angular pressing for structural applications

Abstract

Equal channel angular pressing is a well-known technique to improve ductile materials’ mechanical and microstructural properties even without changing their physical dimensions. A method of intermediate annealing between the passes has previously been introduced to prevent early failure and increase the permissible number of passes. The research work aims to study the effect of intermediate heating on the equal channel angular pressing of the aluminum alloy (AA6082) for application in structural components from ambient to moderate temperatures. A modified equal channel angular pressing die of standard C-type route with a 100 degree channel angle was manufactured to process the alloy. Samples were processed at room temperature with intermediate heating and cooling at 0–250 °C with 25 min of heat soak between passes, and intermediate heating and cooling at 0–300 °C with 25 min of heat soak between passes. The specimens were mechanically characterized by tensile and Vicker hardness tests. Scanning electron microscopy, transmission electron microscope, electron back scattered diffraction techniques were utilized for microstructural analyses for unprocessed and equal channel angular pressing-processed specimens. The results of the study revealed that the intermediate heating (250 °C) is better at reducing the internal stresses generated during the equal channel angular pressing deformation, which permits a greater number of passes and thus significantly improves the resultant mechanical and microstructural properties for structural applications.

Mechanical characteristics and crystallographic texture of AA5083 during Equal Channel Angular Pressing Technique

“…No differences were observed in the grain microstructure, texture, and phase structure before and after annealing, except for a slight shift in the parameter of the α-lattice phase. The observed solute segregation to grain boundaries and the presence of dislocations are believed to be the underlying cause of the observed annealing hardening behavior in UFG AA5083 [53]. These findings suggest a potential approach for developing copper alloys with high strength-ductility synergy.…”