Effect of size and area ratio of primary silicon phase in hyper-eutectic Al–Si alloys on wear under the lubricated condition

The wear behavior of hyper-eutectic Al–Si alloys against bearing steels was investigated under the lubricated condition. The severe-mild wear transition of hyper-eutectic Al–Si alloys occurred when Si-particle size or area ratio exceeded critical values. Below the critical value, Al–Si alloys still remained in the sever wear mode resulting in a large amount of wear due to the insufficient sparse distribution of primary Si phase at the contact area.