Effects of Al-5Sr-5Sb modifiers prepared by various processes on microstructure, thermal conductivity, and mechanical properties of AlSi10MnMg alloy
(1. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China;
2. Key Laboratory of Nonferrous Metal Alloys and Processing, Ministry of Education, Lanzhou University of Technology, Lanzhou 730050, China)
2. Key Laboratory of Nonferrous Metal Alloys and Processing, Ministry of Education, Lanzhou University of Technology, Lanzhou 730050, China)
Abstract: Three kinds of Al-5Sr-5Sb modifiers were prepared by permanent mold casting (PMC), controlled diffusion solidification (CDS), and rolling. The influence of the preparation method on Al-5Sr-5Sb was examined by assessing the melting enthalpy from DSC curves and conducting first-principles calculations. Al-5Sr-5Sb was incorporated into AlSi10MnMg alloy to examine the modification effect and mechanism. It is found that the AlSi10MnMg alloy modified with CDS-prepared Al-5Sr-5Sb shows significant improvement in its microstructure, changing the eutectic Si phase from lamellar to coral-like or fiber-like structures. This modification leads to enhanced macroscopic properties: the thermal conductivity is increased by 24.14% to 189.63 W/(m·K), elongation is increased by 59.15% to 10.87%, and tensile strength is increased by 66.9% to 254.98 MPa compared to the unmodified alloy.
Key words: controlled diffusion solidification; modification; AlSi10MnMg; first-principles; thermal conductivity; mechanical properties