A novel accelerated wear test for magnetic recording disks

Future disk files will operate at lower flying height, thus increasing the possibility of asperity contacts. Conventional tests include sliding (pin-on-disk or slider-on-disk), flying (flyability tests), or contact start/stop modes of operation. A novel accelerated water test (NAWT) was developed to produce intermittent asperity contacts. The NAWT operates in a mixed sliding and flying region, and is designed to operate in a zone of interaction where a significant number of asperity contacts occur. The NAWT uses an acoustic emission sensor to detect asperity contacts. The signal is processed by fast Fourier transform to detect significant increase in the frequency and severity of the contacts. The new apparatus and procedure are presented along with illustrative results