Mark Hahn wrote:
Not sure the vapor pressure of the perfluoroethers that they use as
lubricants
varies that much over the operating temperature regime of a disk
drive.
on the other hand, do these lubricants tend to get sticky or something
at lowish temperatures? the google results showed significantly greater
failures in young drives at low temperatures. (as well as extreme-temp
drives when at end-of-life.)
Hey Mark,
Good question. The properties of perfluoropolyethers (Krytox, Fomblin,
Demnum)
must be well-known, but the Googling I did yielded only a single
reference on
point which I did not want to pay for. The ambient temperature range in
the study
is pretty small which would limit viscosity variation, but when the head
arrives
at a long unread location on a cooler disk maybe there are some shear
effects.
Any disk drive vendors read this list and care to comment?
rbw
--
Richard B. Walsh
"The world is given to me only once, not one existing and one
perceived. The subject and object are but one."
Erwin Schroedinger
Project Manager
Network Computing Services, Inc.
Army High Performance Computing Research Center (AHPCRC)
[EMAIL PROTECTED] | 612.337.3467
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