A Numerical and Experimental Study of the RCF Behaviour of PVD-coated Spur Gears

In this work the rolling contact fatigue (RCF) behaviour of WC/C PVD-coated and uncoated case hardened transmission gears for competition motorcycles was studied both numerically and experimentally. Finite element models of the gears were processed and a theoretical-numerical procedure was applied to the numerical results to predict their RCF life. The presence of the coating and the residual stress fields induced by the surface treatments were simulated. Besides 16NiCr11, which is the actual material of the gears analyzed, the Ti-6Al-4V alloy was also considered with the numerical models. Preliminary RCF tests were carried in both dry and lubricated condition to observe the damage on the tooth flanks with and without the presence of the coating.