Microtibological study of lubricant systems for magnetic tape industry

PMSE 529

Medhat S. Farahat, mfarahat@mint.ua.edu, M. Andrew Nix, Burke Brunson, and David E. Nikles. Center for Materials for Information Technology, The University of Alabama, P.O. Box 870209, Tuscaloosa, AL 35487-0209
Commercial magnetic tape has a mixture of a fatty acid and a fatty acid ester, such as stearic acid and butyl stearate a lubricant. These lubricants transfer from the tape to the recording head where they cause fouling and may corrode GMR read heads. Abrasive additives, such as alumina are added to the tape to remove the transferred material from the head. However, the abrasives increase the head-tape spacing, thereby degrading the recording performance. In the current study, we replace the small molecule lubricants with block copolymer oligomers containing an aliphatic or perfluorinated block and a urethane block. Our purpose in using bound lubricant is to omit the abrasive particles and obtain ultra-smooth low affinity tape surfaces. The challenge is also to create a model system that better describes and evaluates the lubricity efficiency of each lubricant by studying their microtribological behavior under variable testing conditions in terms of their coefficient of friction. The current study aims at investigating the microtribological characteristics of samples containing stearic acid as a commercial lubricant in comparison with our innovated lubricants.