Aluminum metal-matrix composites for automotive applications: tribological considerations

Aluminum alloys possess a number of mechanical and physical properties that make them attractive for automotive applications, but they exhibit extremely poor resistance to seizure and galling. Reinforcement of aluminum alloys with solid lubricants, hard ceramic particles, short fibers and whiskers results in advanced metal - matrix composites (MMC) with precise balances of mechanical, physical and tribological characteristics. Advanced manufacturing technologies such as squeeze infiltration of molten alloys into fiber performs can be employed to produce near net-shape components. Brake rotors, pistons, connecting rods and integrally cast MMC engine blocks are some of the successful applications of Al MMCs in automotive industry. This paper gives an overview of the tribological behavior of Al MMCs reinforced with hard particles, short fibers, and solid lubricants, and the technologies for producing automotive parts from these novel materials.