Role of Reinforcement Particle Size and Its Dispersion on Room Temperature Dry Sliding Wear of AA7075/TiB2 Composites

Abstract

Aluminum alloy based metal matrix composites (AMCs) are widely accepted material in the aerospace, automotive, military, and defence applications due to lightweight and high strength. For tribological applications, high-performance wear-resistant materials like AMCs are the candidate materials. In this investigation, AA7075 based composites with different size TiB2 particles were fabricated using in-situ and ultrasound casting techniques (UST). The AMCs were tested using pin-on-disc tribo tester and the effects of different sized TiB2 particles on wear resistance of AA7075/TiB2 composites have been investigated. The wear resistance of AA7075/TiB2 composite fabricated using UST is found to significantly improve when compared to base alloy and also in-situ composite due to refinement in the particle size, reduced the agglomeration, and improved the distribution of TiB2 particles. The test results also revealed the existence of a mixture of mechanically mixed Al–Zn–Fe intermetallic alloy and oxides of these elements.