Ramp wear and debris from load/unload tab roughness [HDDs]

Summary form only given. The technique of Suk et al [1999] is used to measure in-situ wear and debris generation versus suspension lift-tab roughness during ramp load/unload on a Delrin/spl trade/ ramp. Image processing isolates depressed and raised portions on the ramp which are proportional to wear and debris, respectively. Both wear and debris grow logarithmically and are respectively proportional to average roughness (Ra) and peak roughness (Rp) as determined by Wyko/spl trade/ measurements of the spherical tab. As roughness tends toward zero, both are (not surprisingly) minimized. "Wear" for a Delrin/spl trade/ ramp with smooth tab is more accurately characterized as "deformation". Surface topography is smoothed, but debris is almost absent. Changes in coefficient of friction with L/UL cycles are proportional to peak roughness.