Abstract: A tribological head-disk interface testing system for testing commercial head-disk assemblies in an accelerated fashion to determine wear life, the system comprising an interface stress device disposed on a disk with a wear tester, the interface stress device having a semispherical crystal pin mounted on a slider. Piezoelectric crystals are mounted on the slider.

Abstract: A disk pack spacer ring has formed thereon a plurality of pairs of intercommunicating scoop/pump channels which prevent formation of solid body rotation of air between closely spaced disk surfaces so that the entire space between the disk surfaces is ventilated. A scoop channel angled into the direction of rotation scoops air into the channel, and a intercommunicating pump channel angled away from the direction of rotation pumps the scooped air out in a direction opposite to disk rotation. In one embodiment, the scoop and pump channels are disposed on upper and lower surfaces of the ring and a flow through channel disposed on the inner surface of the ring connects the two.

Abstract: Apparatus is disclosed, for mechanically agitating, in a non-reciprocating manner, a permalloy composition used in an electroplating procedure, in such a way as to apply a film of improved uniformity of composition and thickness thus avoiding limitations of prior electroplating processes which, due to uneven boundary layer flow patterns caused by reciprocating agitation, result in non-uniformities in film composition and thickness.