Effect of Zn Concentration on the Microstructure and Mechanical Properties of Al-Mg-Si-Zn Alloys Processed by Gravity Die Casting
Year: 2018
Type: article
Abstract: The microstructure and mechanical properties of Al-8.1Mg-2.6Si-(0.08 to 4.62)Zn alloys (in wt pct) have been investigated by the permanent mold casting process. X-ray diffraction analysis shows that theτ-Mg32(Al, Zn)49phase forms when the Zn content is 1.01 wt pct. With higher Zn contents of 2.37 and 3.59 wt pct, theη-MgZn2andτ-Mg32(Al, Zn)49phases precipitate in the microstructure, and theη-MgZn2phase forms when the Zn content is 4.62 wt pct. Metallurgical analysis shows that theη-MgZn2andτ-Mg32(Al, Zn)49phases strengthen the Al-8.1Mg-2.6Si-(0.08 to 4.62)Zn alloys. After solutionizing at 510 °C for 180 minutes and aging at 180 °C for 90 minutes, theη′-MgZn2phase precipitates in theα-Al matrix, which significantly enhances the mechanical properties. Addition of 3.59 wt pct Zn to the Al-8.1Mg-2.6Si alloy with heat treatment increases the yield strength from 96 to 280 MPa, increases the ultimate tensile strength from 267 to 310 MPa, and decreases the elongation from 9.97 to 1.74 pct.
Institutions: General Research Institute for Nonferrous Metals (China), Brunel University of London, University of Science and Technology Beijing, Southern University of Science and Technology, Northwestern Polytechnical University, State Key Laboratory of Solidification Processing, Colorado School of Mines
Language: English
Subfield: Metals and Alloys
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,990
OpenAlex ID: W2806782142