MICROSTRUCTURE AND MECHANICAL PROPERTIES CHARACTERIZATION OF Al-TiB_2 METAL MATRIX COMPOSITES PROCESSED USING IN-SITU TECHNIQUE

摘要

An aluminium based metal matrix was reinforced with TiB_2 particulates by an in-situ reaction process using K_2TiF_6 and KBF_4 salts. The effects of reaction holding time on the microstructure and mechanical properties were investigated. X-ray diffraction analysis confirmed the presence of TiB_2 in the aluminium matrix. Microscopic investigation carried out on the composite samples revealed the presence of hexagonally shaped submicron size TiB_2 particulates with a reasonably clean interface with the aluminium matrix. Ambient temperature mechanical properties showed an increase in 0.2% YS, and the UTS and a decrease in the ductility of the reinforced composites compared to that of unreinforced material. Mechanical properties of the composites as related to the fabrication and microstructural features are discussed.