Abstract

Aluminum alloys are attractive for critical applications such as pistons, clutch housings and liners in automotive industry for their high strength to weight ratio, high corrosion resistance and good heat conductivity. These alloys can be fabricated using casting and powder metallurgy techniques in which porosity is a common feature. The presences of pores adversely affect the mechanical properties and wear resistance of these components. Not only the total area percentage of porosity influences the degradation in properties but also size, shape and interconnectivity of pores play an important role. In this study, aluminum alloys were produced using powder metallurgy technique. The amount of porosity was varied by varying compaction pressure and amount of wax added before compaction. Reciprocating wear tests (ball-on-flat configuration) were performed against AISI 52100 bearing steel ball under both low (1.5- 5N) and high (6-20N) loads. Scanning electron microscopy was employed in order to identify possible wear mechanisms. Both detrimental and beneficial effects of porosity under different loading conditions were observed. An attempt has been made to develop a relationship between pore size and distribution and wear behavior of aluminum alloys.