Microstructure and tensile properties of TiB2p/6061Al composites
(1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. School of Astronautics, Harbin Institute of Technology, Harbin 150001, China;
3. Research Institute, PetroChina Dushanzi Petrochemical Company, Kelamayi 833600, China)
2. School of Astronautics, Harbin Institute of Technology, Harbin 150001, China;
3. Research Institute, PetroChina Dushanzi Petrochemical Company, Kelamayi 833600, China)
Abstract: 14% and 20% (volume fraction) TiB2p/6061Al composites were fabricated by pressure infiltration method, and then were extruded. The microstructure and properties of TiB2p/Al composites before and after extrusion were studied by TEM, SEM and tensile method. The results show that TiB2 particles employed are equiaxed polyhedrals and are well wetted with the aluminum alloy. Hot extruding is effective in eliminating defects such as pores, which are induced in the fabrication process. After T6 treatment and extrusion treatment, elastic modulus, tensile strength and elongation of 14%TiB2p/6061Al composites are 107 GPa, 364.1 MPa and 9.25%, respectively. While those of 20%TiB2p/6061Al composites are 120 GPa, 472.6 MPa and 9.79%, respectively, which show high strength and plasticity. A lot of dimples and a few cracked particles are observed on the fracture surfaces of the composites, which indicates good plasticity of the composites. The high strength and plasticity of TiB2p/6061Al composites are attributed to good bonding between TiB2 particles and aluminum alloy.
Key words: TiB2p/Al composites; microstructure; tensile behavior; high plasticity