Effects of Pouring Temperature and Electromagnetic Stirring on Porosity and Mechanical Properties of A357 Aluminum Alloy Rheo-Diecasting
Autor: | Junwen Zhao, An Guo, Jing Han, Xu Zhang, Chao Xu, Hu Li |
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Rok vydání: | 2018 |
Předmět: |
0209 industrial biotechnology
Materials science Mechanical Engineering Alloy chemistry.chemical_element 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology Microstructure 020901 industrial engineering & automation chemistry Mechanics of Materials Aluminium Ultimate tensile strength engineering Slurry General Materials Science Composite material Elongation 0210 nano-technology Porosity Shape factor |
Zdroj: | Journal of Materials Engineering and Performance. 27:2373-2380 |
ISSN: | 1544-1024 1059-9495 |
Popis: | Semisolid slurry of A357 aluminum alloy was prepared using a temperature-controllable electromagnetic stirrer and rheo-diecast at different temperatures. The effects of pouring temperature and electromagnetic stirring (EMS) on the porosity in rheo-diecast samples, as well as the relation between porosity and mechanical properties, were investigated. The results show that pouring temperature and EMS had minor influences on rheo-diecast microstructure but marked influence on the porosity. With decreasing slurry pouring temperature, the porosity decreased first and then increased, whereas the maximum pore ratio (ratio of shape factor to diameter of the largest pore) increased first and then decreased. The maximum pore ratio determines the level of tensile strength and elongation, and higher mechanical properties can be obtained with smaller and rounder pores in samples. The mechanical properties of the rheo-diecast samples increased linearly with increasing maximum pore ratio. The maximum pore ratio was 1.43 µm−1, and the minimum porosity level was 0.37% under EMS condition for the rheo-diecast samples obtained at a pouring temperature of 608 °C. With this porosity condition, the maximum tensile strength and elongation were achieved at 274 MPa and 4.9%, respectively. It was also revealed that EMS improves mechanical properties by reduction in porosity and an increase in maximum pore ratio. |
Databáze: | OpenAIRE |
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