Accelerated wear testing of head-disc interfaces

To better assess wear characteristics of head and media combinations under conditions that approximate drive operation, we describe an accelerated wear test in which the z-height is increased so that the trailing edge of the air bearing surface makes contact. Using this test, we find that the wear rate for a particular head-media combination decreases as time1/2 and we document the effect of media wear on the head wear rate. These experimental findings are combined with numerical modeling of head-disc interface wear that correlates well with our results and predicts a shift in wear mechanisms as surface deformation shifts from dominantly plastic to elastic.