TY - JOUR
T1 - Influence of melt flow in the gating system on microstructure and mechanical properties of high pressure die casting AZ91D magnesium alloy
AU - Li, Xiaobo
AU - Yu, Wenbo
AU - Wang, Junsheng
AU - Xiong, Shoumei
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/10/24
Y1 - 2018/10/24
N2 - 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 (~ 16% higher ultimate tensile strength) and ductility (~ 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.
AB - 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 (~ 16% higher ultimate tensile strength) and ductility (~ 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.
KW - Externally solidified crystals
KW - High pressure die casting
KW - Magnesium alloy
KW - Mechanical properties
KW - Porosity
UR - http://www.scopus.com/inward/record.url?scp=85052902392&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2018.08.090
DO - 10.1016/j.msea.2018.08.090
M3 - Article
AN - SCOPUS:85052902392
SN - 0921-5093
VL - 736
SP - 219
EP - 227
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
ER -