Simon Lawes is working as the Experimental Officer for the Mechanics of Materials research group at the University of Leicester, where he has been based for the last six years studying for his Bachelors and PhD. His current research is the use of novel coatings for application in the automotive valve-train

The Relevance of High-angle Inclined Impact Testing of Diamond-like Carbon for Engine Valve-train Applications

The demands of reducing engine losses and replacement of additives such as zinc dialkyl dithio phosphate are driving engine manufacturers to consider technologies such as diamond-like carbon (DLC) coating for the wear protection of components and the provision of low friction operation.

This coating of valve-train components could provide considerable reduction in engine losses. Valve-train component interactions are tribologically complex, with contacts commonly experiencing mixed boundary and elasto-hyrdodynamic lubricated sliding and abrasive wear, impact, and fatigue. This places demands on the performance of potential coatings.

This work compares coating performance in a valve-train testing rig with coating performance under inclined impact testing, and illustrates the importance of inclined impact testing in selection of DLC coatings for valve-train applications.