Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7980957 | Materials Science and Engineering: A | 2014 | 22 Pages |
Abstract
The effects of the melt temperature on the relative densities, microstructures and mechanical properties of vacuum counter-pressure casting A357 alloys solidified under grade-pressurising (200 kPa) were investigated. The results indicated that the relative densities and mechanical properties of samples solidified under grade-pressurising were affected by the melt temperature (580-610 °C). The optimal relative density and mechanical properties were achieved at a melt temperature of 590 °C. The microstructures varied with the melt temperature as a result of the differences in the strengths of the feeding flow and dendrites. The powerful feeding flow caused by grade-pressurising solidification can induce stress on the dendrites, resulting in the collapse of the primary dendrite network to form equiaxed dendrites. Decreasing the feeding pressure proportionally to the solid volume fraction was proposed to obtain a suitable melt temperature for improving the density and refining the microstructure.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Bowen Xiong, Xin Lin, Zhenjun Wang, Qingsong Yan, Huan Yu,