Effect of TiB₂ content and temperature on sliding wear behavior of AA7075/TiB₂ in situ aluminum cast composites

Aluminum alloy AA7075 reinforced TiB₂ particulate composites were prepared by the in situ reaction of K₂TiF₆ and KBF₄ to molten aluminum. The prepared aluminum matrix composites (AMCs) were characterized using X-ray diffraction and scanning electron microscopy (SEM). The sliding wear behavior of the AMCs was evaluated using a pin-on-disc wear apparatus. The effect of TiB₂ particulate content (0, 3, 6 and 9wt%) and temperature (30, 60, 90, 120, 150, 180, 210 and 240°C) on wear rate and worn surface of the AMCs were studied. The results indicated that TiB₂ particles were effective to enhance the wear resistance of the AMCs at all test temperatures studied in this work. The wear rate of the AMCs increased when the applied temperature was increased. The in situ formed TiB₂ particles pushed the transition wear temperature by another 30°C. The wear mode was observed to be abrasive at room temperature and metal flow at high temperature.