Aluminum is a common bearing material where weight reduction is important.  It is also a virtually inert material and has a high resistance to oil oxidation.  Aluminums reserve properties similar to bronze and it exhibits superior performance compared to steel during catastrophic events.  The designer must pay attention to contact pressure of the bearing to housing, and thermal growth of the bearing during operation due to its high coefficient of thermal expansion.  But Aluminum’s relatively affordable, and stable, cost make it an attractive bearing material.