Microstructure, tensile properties and creep behavior of Al-12Si-3.5Cu-2Ni-0.8Mg alloy produced by different casting technologies
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2018年第7期
论文作者：Lijie Zuo Bing Ye Jian Feng Xiangyang Kong Haiyan Jiang Wenjiang Ding
文章页码：1222 - 1228
摘 要：The relationship between the as-cast microstructure and mechanical properties of the Al-12 Si-3.5 Cu-2 Ni-0.8 Mg alloys produced by permanent mold casting（PMC） and high pressure die casting（HPDC）is investigated. The alloys in both PMC and HPDC consist of Al, Si, Al5 Cu2 Mg8 Si6, Al3 Cu Ni, and Al7 Cu4 Ni phase. However, the microstructure of the HPDC alloy is significantly refined. Compared to the PMC alloy,the ultimate tensile strength of the HPDC alloy is significantly increased from 244 MPa to 310 MPa, while the elongation shows a reverse trend at room temperature. At low stress and temperature range, slight variations of stress exponent and activation energy indicate that the minimum creep rate is controlled by the grain boundary creep. Then the minimum creep rate is higher for the specimen with the smaller grain size, where grain boundary creep is the dominant creep mechanism. At high stress region, the stress exponent for the PMC alloy and HPDC alloy is 5.18 and 3.07, respectively. The different stress exponents and activation energies measured at high stress and high temperature range indicates that the creep mechanism varies with the casting technologies.
Lijie Zuo1，Bing Ye1，Jian Feng1，Xiangyang Kong2，Haiyan Jiang1，Wenjiang Ding1
1. National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University2. Institute of Materials for Mobile Energy, School of Materials Science and Engineering, Shanghai Jiao Tong University
摘 要：The relationship between the as-cast microstructure and mechanical properties of the Al-12 Si-3.5 Cu-2 Ni-0.8 Mg alloys produced by permanent mold casting（PMC） and high pressure die casting（HPDC）is investigated. The alloys in both PMC and HPDC consist of Al, Si, Al5 Cu2 Mg8 Si6, Al3 Cu Ni, and Al7 Cu4 Ni phase. However, the microstructure of the HPDC alloy is significantly refined. Compared to the PMC alloy,the ultimate tensile strength of the HPDC alloy is significantly increased from 244 MPa to 310 MPa, while the elongation shows a reverse trend at room temperature. At low stress and temperature range, slight variations of stress exponent and activation energy indicate that the minimum creep rate is controlled by the grain boundary creep. Then the minimum creep rate is higher for the specimen with the smaller grain size, where grain boundary creep is the dominant creep mechanism. At high stress region, the stress exponent for the PMC alloy and HPDC alloy is 5.18 and 3.07, respectively. The different stress exponents and activation energies measured at high stress and high temperature range indicates that the creep mechanism varies with the casting technologies.
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