Development of NiP conversion overcoat

Author

Yanagisawa, M. ; Yamamoto, T. ; Shiota, N. ; Tsukamoto, Y. ; Goto, F.

Author_Institution

NEC Corp., Kawasaki, Japan

Volume

25

Issue

5

fYear

1989

fDate

9/1/1989 12:00:00 AM

Firstpage

3734

Lastpage

3736

Abstract

An NiP conversion overcoat has been developed for plated magnetic disks by thermal oxidation of an NiP film followed by chromate passivation. The overcoat shows high corrosion resistance and good wear resistance. The chromate passivator (chromium trioxide) markedly improves corrosion resistance on the NiP conversion overcoat by passivation of pinholes. The lubricant, composed of perfluoro polyether, improves the wear rate by 1/100 or 1/1000. Contact start/stop durability for more than 100000 cycles has been achieved on the lubricated NiP conversion overcoat. Wear of the overcoat, consisting of NiO-NiP layers, begins with plastic deformation of metal underlayers. The NiO layer itself shows no cracks or delamination

Keywords

corrosion protective coatings; hard discs; lubrication; nickel compounds; passivation; wear resistant coatings; CrO₃; NiO-NiP layers; NiP conversion overcoat; chromate passivation; contact start/stop durability; corrosion resistance; lubricant; metal underlayers; perfluoro polyether; plastic deformation; plated magnetic disks; thermal oxidation; wear resistance; Amorphous materials; Chromium; Corrosion; Grain boundaries; Lubricants; Magnetic films; Manufacturing processes; Nickel; Oxidation; Passivation;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.42417

Filename

42417