Effect of TiB2 Particles on the Morphological, Mechanical and Corrosion Behaviour of Al7075 Metal Matrix Composite Produced Using Stir Casting Process

Aluminium metal matrix composites are lightweight high-performance materials mostly applicable in aerospace, automobile and marine applications. In this study, the morphological, mechanical and corrosion behaviour of Al7075 metal matrix composites were investigated to find the effect of reinforcement of TiB 2 particles for various weight percentage. Al7075-TiB 2 composites were developed by reinforcing the 3–5 µm size TiB 2 ceramic particles using stir casting process. The particles with different weight percentage of 2, 4, 6 and 8 were uniformly reinforced with the help of the mechanical stirrer. The energy dispersive X-ray diffraction (EDAX) pattern confirms the presence of TiB 2 particles in the composites. SEM and optical microstructures clearly revealed the uniform distribution of TiB 2 particles in the aluminium matrix. The additions of TiB 2 particles enhance the tensile strength and micro hardness due to the strong interface and load sharing between the matrix and the reinforcement particles. Dry sliding wear test was conducted by varying the applied load and sliding distance. SEM microstructure of worn surfaces shows that addition of TiB 2 particles decreases the wear rate due to the presence of stiffer and stronger reinforcement particles. The electrochemical potentiodynamic polarization and salt spray test were also conducted to study the corrosion behaviour of the Al-TiB 2 composites. SEM microstructures confirm the occurrence of pitting corrosion and shows that addition of TiB 2 particles improves the corrosion resistance.