Improving the Wear Resistance of 440C Bearing Steel Balls by Adding ZrO2 in Mechanical Alloying

The wear resistance of 440C bearing steel balls significantly impacts the reliability of bearings. Our method for increasing the wear resistance of steel balls combines mechanical alloying to create nanogradient structures with ZrO2 doping on the surface of the steel balls. The results revealed that ZrO2 formed mechanical alloying on the surface of the steel balls. Under all loads, the processed samples exhibited excellent wear resistance. Compared to untreated samples, the wear of processed samples subjected to 20, 40, and 60 N loads decreased by 28.82%, 50.25%, and 50.79%, respectively. The existing literature indicates that adding ZrO2 powder during mechanical alloying is a promising method for improving the friction performance of bearing steel balls.