Visualizing Tire Wear

Durability is a key attribute consumers want from their tires; however, predicting the longevity of a tire without performing time consuming and costly wear trials has remained largely an unfulfilled ambition of the tire industry.  Well established laboratory accelerated wear tests, such as DIN and Akron abrasion, are unable to predict on-the-road wear reliably, often showing no correlation with in-service performance ranking.  The reason for this is that wear in service is governed by numerous parameters that change over the lifetime of the tire while laboratory tests, aimed at shortening and simplifying the wear process are unable to replicate all variables experienced by a tire.  The chemical and mechanical processes involved in the detachment and removal of particles of rubber from the surface are still not well understood.

An initial assessment of tread wear has been made by comparing surface characteristics of tires and test pieces, using techniques including light microscopy (LM) and transmission electron microscopy (TEM).  TEM was used to visualize the worn surfaces of samples embedded in a polystyrene matrix.  Differences between laboratory abrasion and on-the-road tire tread wear have been observed in the microstructure of tread compounds that may indicate how particles of rubber could become detached from the tread surface.  These techniques are helping to ascertain a mechanistic insight into the mode of tread removal and degradation, which it is hoped will ultimately assist in developing and validating a laboratory method to predict tire wear accurately during the tire compound development process.