Minoru Ichijo

Lubrication of surface oxidized Co–Cr thin films by phosphoric and phosphorous acid esters

Abstract Phosphoric and phosphorous acid esters have been applied to surface oxidized Co–Cr thin films, and their lubrication performances are investigated. Tricresyl phosphate, phosphoric and phosphorous acid esters with long alkyl chains are found to be very effective in reducing friction and wear of thin films. Such excellent lubrication performances could be attributed to their strong adsorption to the oxide surfaces and large cohesive energy between the lubricant molecules. These results are discussed in detail.

Improvement of durability and corrosion resistance of metal evaporated tape with chemically deposited SiO/sub x/ overcoat

To improve the reliability of metal evaporated tape (ME tape), SiO/sub x/ overcoat was investigated. The durability of ME tape overcoated with SiO/sub x/ was greatly improved by lubricating with C/sub 18/H/sub 37/OP(H)(O)OH (mono octadecyl phosphite: MOP), which showed more than 10 hours life time in a still mode durability test (relative speed of head to media: 11.3 m/s). Since MOP was solid at room temperature, adhesion did not occur and friction force during the test reduced by 25% compared with perfluoropolyether liquid lubricant. Corrosion of ME tape was prevented by SiO/sub x/ overcoat prepared by plasma enhanced chemical vapor deposition (PECVD). Water transmission rate of PECVD-SiO/sub x/ was one tenth that of physically deposited SiO/sub x/, which suppressed surface corrosion of ME tape in an atmosphere of 60/spl deg/C 90%R.H. and of 4 ppm SO/sub 2/ (40/spl deg/C 80%R.H.).