Fatigue failure of all-steel and steel–silicon nitride rolling ball combinations

The fatigue life of all-steel and silicon nitride–steel ball combinations with a focus on the fatigue life of the steel components was experimentally studied using a four-ball tester. The rolling contact fatigue (RCF) tests were conducted according to the IP-300 standard with a rotational speed of 10,000 rpm. The L10 of the AISI M50 tool steel components rolling against silicon nitride (Si3N4) balls were observed to be 6 times shorter than that of all-M50 steel bearing configurations. Also, the L10 life of the AISI 52100/Si3N4 combination was 2.3 times shorter than the L10 of all-AISI 52100-steel systems. Since the RCF life of a rolling system is determined by the life of its first component to fail, the steel/silicon nitride hybrid rolling combinations’ overall advantage over all-steel ones using the currently used steel bearing materials such as AISI 52100 and M50 is questionable.