Microstructural Refinement and Corrosion Resistance Improvement of Heat-Treated A356 Alloy Processed by Equal Channel Angular Pressing

Abstract

The microstructure refinement, hardness and corrosion resistance of heat-treated A356 aluminium alloy processed by equal-channel angular pressing (ECAP) were investigated. ECAP was carried out at room temperature using a mold, with a channel angle of 120° via route A. Results of the investigation confirm that the flaky coarse silicon particles were effectively fragmented from 4.22 to 0.761 µm and the grain size reduced from 171 to 40 µm after four passes of heattreated as-cast using ECAP process. ECAP processing increases the hardness of heat-treated as-cast alloy from 61 Hv to 125 HV after four passes. Heat-treated A356 alloy shows enhanced corrosion resistance from 0.0424 to 0.00149 mmy-1 , after four passes. In this research, ECAP processing has been shown to improve the hardness and corrosion resistance of as-cast A356 alloy.

Influence of Corrosive Environment on Fatigue and Mechanical Properties of Al Cast Alloy with Higher Fe Content

“…The increased Mg content results in a higher susceptibility of Al alloys to intergranular corrosion or stress cracking. The Mg2Si phase is even more "active" compared to the Al alloy matrix or silicon itself and contributes to pitting or intergranular corrosion [19][20] focused on investigating the corrosion behavior of AlSi7Mg0.3 alloy before and after heat treatment. Vargel [14] stated that the presence of larger eutectic Si particles, in non-heat-treated alloys, caused the formation of pitting corrosion largely compared to heat-treated alloys.…”

The Influence of a Corrosive Environment on Fatigue and Mechanical Properties of an Al-Cast Alloy with Higher Fe Content

“…The Mg2Si phase is even more "active" compared to the Al alloy matrix or silicon itself and contributes to pitting or intergranular corrosion. The authors of [21,22] focused on investigating the corrosion behavior of AlSi7Mg0.3 alloys before and after heat treatment. Vargel [16] stated that the presence of larger eutectic Si particles in non-heat-treated alloys largely caused the formation of pitting corrosion compared to heat-treated alloys.…”