Thermal Stability of AA1050 Aluminum Alloy after Equal Channel Angular Pressing

Abstract

The annealing behavior of AA1050 aluminum alloy deformed by equal-channel angular pressing (ECAP) was studied experimentally. The material was subjected to extrusion through die with channels intersecting at an 90° angle. Samples were pressed for up to 8 passes using route B C , then cut into slices and subsequently annealed for 1 hour at temperatures from 100°C to 350°C. Hardness measurements were performed on each slice. Microstructure of material was analyzed in the longitudinal section by means of Electron Backscatter Diffraction system in a scanning electron microscope (EBSD/SEM). From the obtained sets of Kikuchi diffraction patterns orientation maps and Image Quality maps were determined. Grain size, disorientation distributions and crystallographic texture were also estimated. ECAP caused significant improvement of hardness, with stabilization after 4 passes. Refinement of microstructure was obtained with the increasing amount of passes. Material properties were stable during annealing at temperatures lower than 150°C. Annealing at higher temperatures caused a decrease in hardness corresponding to an increase of the grain size.

Adaptive Stretch-Forming Process: A Computer Vision and Statistical Analysis Approach

“…Despite the low values for the yield strength (R p0.2 = 28 MPa) and UTS (R m = 76 Mpa), this alloy was used for the specific state "O", having improved elongation at break capability; compared to other states (H14, H16, or H18) that offer superior yield and ultimate tensile strength, but only 8 to 12% elongation, this alloy was capable of up to 39% elongation at break. It was the subject of numerous studies, including the analysis of corrosion resistance, mechanical properties, and microstructure by continuous closed die forging [49] or carbonized eggshell [48], hybrid surface nanocomposite by multi-pass friction stir processing [50], thermal stability after equal channel angular pressing [51], layered sandwich composite materials [37,38], and explosive welded laminate [52]. A GOM Atos II 400 3D scanner image measurement system, highlighted in Figure 8a, was used to obtain precise measurements.…”