Study On Multiphase Particulates Reinforced Aluminum Matrix Composites

Multiphase particulates reinforced aluminum matrix composites—(TiB₂+SiC) /ZL109, (TiB₂+Al₂O₃)/ZL202 and (TiB₂+ZrB₂)/Al, which were fabricated by Mixing Salts Reaction, two step method and synthesization method, are investigated in this thesis. By means of X-ray diffraction (XRD), electron-probe micro-analyzer (EPMA), optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and high-resolution transmission electron microscope (HRTEM), the microstructure, distribution of reinforcements and mechanical properties of composites were analyzed. In addition, some research about the mechanical properties of TiB₂ particulate reinforced piston alloy composites and the TiB₂/Al interface properties were made in this thesis.Fabrication technology of (TiB₂+SiC)/ZL109 composites by stirring casting and in-situ method is available. It was observed that the distribution of TiB₂ and SiC particulate is homogeneous and some TiB₂ agglomerations exist in grain boundary. SiC particulate is cuspate shape. The TiB₂ agglomerations interlace with the SiC particulate and coralline-like eutectic Si. The results of hardness tests and tensile experiments at room temperature reveal that the hardness of the (TiB₂+SiC)/ZL109 composites is obviously higher than that of the composites reinforced by the same amount single reinforcements. The tensile strength of the (TiB₂+SiC)/ZL109 composites is slightly higher than the composites reinforced by the same amount single reinforcements and it...