Effects of Complex Modification by Sr-Sb on the Microstructures and Mechanical Properties of Al-18 wt % Mg₂Si-4.5Cu Alloys

Youhong Sun; Shaoming Ma; Huiyuan Wang; Lei Chen; Ke Gao; Yinlong Ma; Baochang Liu

doi:10.3390/ma9030157

Effects of Complex Modification by Sr-Sb on the Microstructures and Mechanical Properties of Al-18 wt % Mg₂Si-4.5Cu Alloys

Materials (Basel). 2016 Mar 4;9(3):157. doi: 10.3390/ma9030157.

Authors

Youhong Sun^{1

2}, Shaoming Ma^{3

4}, Huiyuan Wang⁵, Lei Chen⁶, Ke Gao^{7

8}, Yinlong Ma^{9

10

11}, Baochang Liu^{12

13}

Affiliations

¹ School of Construction Engineering, Jilin University, Changchun 130026, China. syh@jlu.edu.cn.
² Key Laboratory of Drilling and Exploitation Technology in Complex Conditions, Ministry of Land and Resources, No. 938 Ximinzhu Street, Changchun 130026, China. syh@jlu.edu.cn.
³ School of Construction Engineering, Jilin University, Changchun 130026, China. masm14@mails.jlu.edu.cn.
⁴ Key Laboratory of Drilling and Exploitation Technology in Complex Conditions, Ministry of Land and Resources, No. 938 Ximinzhu Street, Changchun 130026, China. masm14@mails.jlu.edu.cn.
⁵ Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, No. 5988 Renmin Street, Changchun 130025, China. wanghuiyuan@jlu.edu.cn.
⁶ Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, No. 5988 Renmin Street, Changchun 130025, China. chenl11@mails.jlu.edu.cn.
⁷ School of Construction Engineering, Jilin University, Changchun 130026, China. gaokenm@jlu.edu.cn.
⁸ Key Laboratory of Drilling and Exploitation Technology in Complex Conditions, Ministry of Land and Resources, No. 938 Ximinzhu Street, Changchun 130026, China. gaokenm@jlu.edu.cn.
⁹ School of Construction Engineering, Jilin University, Changchun 130026, China. ylma@jlu.edu.cn.
¹⁰ Key Laboratory of Drilling and Exploitation Technology in Complex Conditions, Ministry of Land and Resources, No. 938 Ximinzhu Street, Changchun 130026, China. ylma@jlu.edu.cn.
¹¹ Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, No. 5988 Renmin Street, Changchun 130025, China. ylma@jlu.edu.cn.
¹² School of Construction Engineering, Jilin University, Changchun 130026, China. liubc@jlu.edu.cn.
¹³ Key Laboratory of Drilling and Exploitation Technology in Complex Conditions, Ministry of Land and Resources, No. 938 Ximinzhu Street, Changchun 130026, China. liubc@jlu.edu.cn.

Abstract

This research was carried out to investigate the influence of Sr-Sb on the microstructures and mechanical properties of Al-18 wt % Mg₂Si-4.5Cu alloys. After the addition of 0.2 wt % Sr-Sb, the morphologies of primary Mg₂Si transformed from equiaxed dendrite to cube in as-cast alloys and the average size of primary Mg₂Si decreased from ~50 to ~20 μm. The shape of eutectic Mg₂Si changed from Chinese script to short rod. After extrusion and T6 heat treatment, the ultimate tensile strength of modified alloy at room temperature (RT) and 100 °C increased respectively from 229 to 288 MPa, and from 231 to 272 MPa. The elongation-to-failure only slightly improved from 2.9% to 3.8% and from 3.3% to 3.7% at RT and 100 °C, respectively. The tensile fracture surface revealed a transition from brittle fracture to ductile fracture after modifying by 0.2 wt % Sr-Sb.

Keywords: aluminum alloy; composite; grain refinement; mechanical properties; modification.