An INVESTIGATION OF DISTINCTIVE SOLUTIONIZING PROCESS PARAMETERS ON SIGNIFICANTLY INCREASING IN STRENGTH AND DUCTILITY OF As-CAST AZ80 Mg ALLOY

Authors

  • Mui Kheng Yeoh ST Engineering Land Systems Ltd https://orcid.org/0000-0001-9327-8121
  • XingHe ST Engineering Land Systems Ltd
  • Richard SMRT Corporation Ltd
  • Teik-Cheng Lim Singapore University of Social Sciences

DOI:

https://doi.org/10.36547/ams.26.4.723

Keywords:

Cast AZ80 Mg alloy, Heat Treatment, Annealing Twins, Solutionizing, Strength, Ductility

Abstract

A distinctive solutionizing process parameter was developed and performed to significantly enhance strength and ductility of aged AZ80 Mg alloy.  The microstructure-processing-properties relationship was studied to help elucidate the mechanism.  Microstructure and mechanical properties were studied by using optical microscopy, Field Emission Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray diffraction, hardness and tensile testing.  The results show that the solutionization at 380°C/10h followed by 420°C/10h promoted significant dissolution of eutectic Mg17Al12 and intermetallic phases.  After standard aging at 200°C/10h, the formation of high-density precipitates Mg17Al12 with more spheroidization precipitates and lesser discontinuous precipitates morphology, which was not observed in conventional heat treatment for aged AZ80 Mg alloy.  Fine precipitates Mg17Al12 resulted in a significant increase in ultimate tensile strength (50.3%), yield strength (35%), elongation (106%) and hardness (40%) compared to conventional heat treated cast AZ80 Mg alloy.  These properties are comparable to the commonly used aerospace grade cast aluminium alloy A356.

Downloads

Published

2020-12-07

Issue

Section

Research papers