Properties investigation and microstructures characterization of SiCp/6061Al composites produced by PM route

2nd International Conference on New Material and Chemical Industry

材料科学;化学工业

Wang, A.Q.^1 ; Tian, H.W.^1 ; Xie, J.P.^1,2

School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang

471023, China^1

Non-Ferrous Metal Generic Technology Collaborative Innovation Center of Henan Province, Luoyang

471023, China^2

关键词: 6061 Aluminium alloy matrix;    After-heat treatment;    Combination mechanisms;    Hot-pressed composites;    Inter-metallic particle;    Interface mi-crostructure;    Microstructures and properties;    The scanning electron microscopes (SEM);   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/292/1/012055/pdf
DOI  :  10.1088/1757-899X/292/1/012055

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In this study, 35 vol.% SiC particles with different sizes reinforced 6061 aluminium alloy matrix composites were prepared by a powder metallurgy method. The Scanning Electron Microscope (SEM) images of composites were observed, the Coefficient of Thermal Expansion (CTE) and tensile strength of composites were examined, and the influences of SiC particle size on microstructures and properties of the composites were analyzed. Furthermore, the SiCp/6061Al composites with SiC particle size of 7.5 μm were selected to investigate the SiCp/Al interface microstructure and precipitated phases by the means of SEM, TEM and HRTEM. The study indicated that, with the increase of SiC particle size, the SiC particles distributed more uniformly in the matrix, the CTE of composites increased, but the tensile strength of composites decreased. The SiCp/Al interface in this experiment is clean and smooth, and the combination mechanism of SiC and Al is the formation of a half coherent interface by closely matching of atoms. Some micron-sized coarse intermetallic particles existed in the hot-pressed composites, such as random-shaped Mg2Si, long stick shaped Al15(Mn, Fe, Cu)3Si2. When the composites were solution treated at 510 °C for 2 h and then aging treated at 190 °C for 9 h, except long stick shaped Al15(Mn, Fe, Cu)3Si2, numerous nano-sized precipitated phases (Mg2Si) with diameters of 50-200 nm dispersively distributed in the matrix. After heat treatment, the tensile strength of composite with SiC particle size of 7.5 μm enhance from 298 MPa to 341 MPa.