Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10142013 | Materials Science and Engineering: A | 2018 | 30 Pages |
Abstract
The influence of melt flow in the gating system on microstructure and mechanical properties of high pressure die casting AZ91D magnesium alloy was investigated. Experimental and theoretical results showed that the externally solidified crystals (ESCs) were broken and eliminated by the shear stress caused by the turbulent melt flow in gating system. In comparison with the casting fabricated with conventional gating system, a simultaneous increase in both strength (~â¯16% higher ultimate tensile strength) and ductility (~â¯70% higher elongation) were achieved in the casting fabricated with modified gating system. Furthermore, different modes of crack initiation and propagation were found. For the one fabricated with the conventional gating system, the crack initiated at the shrinkage pore and propagated in a quasi-cleavage fracture form. In contrast, for the other one fabricated with the modified gating system, micro-voids appeared between the α-Mg grains and β-Mg17Al12 phase, and crack propagated in a ductile form.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Xiaobo Li, Wenbo Yu, Junsheng Wang, Shoumei Xiong,