The influence of porosity and hot isostatic pressing treatment on wear characteristics of cast and P/M aluminum alloys

Porosity is a common feature of cast and sintered aluminum alloys and strongly influences their properties and applications. Al–Si alloys are widely used in a variety of automotive components due to their excellent strength to weight ratio. Porosity adversely affects the mechanical properties and wear resistance of these components. In the present investigation, dry sliding wear behavior was investigated in the load range 6–20 N against AISI 52100 bearing steel ball using a reciprocating ball-on-flat configuration at a frequency range of 4–20 Hz for cast and 15 Hz for sintered samples. It is found that, wear within the present load and frequency ranges is due to plastic deformation and delamination. It was also found that hot isostatic pressing treatment (HIP) decreases the total amount of porosity and average pore size, but at the expense of reduced hardness. The competition between the beneficial effect of lower porosity and the detrimental effect of lower hardness determines the final wear rate.