Start up and steady state friction of alumina against alumina

Using a pin-on-disc testing machine, the authors investigated the start up and steady state friction of highly polished alumina against itself and studied the factors affecting the friction. The lubricants used in this paper were 1 wt.% water solution of carboxymethyl cellulose sodium salt (CMC-Na 1 wt.% water solution) and distilled water. It is observed that many factors, such as lubricants, load, sliding velocity, resting time and start up acceleration etc., have an influence on the friction of alumina against alumina. The experimental results indicate that the coefficients of the start up and steady state friction when CMC-Na 1 wt.% water solution is the lubricant are much smaller than when distilled water is used, and it is possible that alumina-on-alumina hip joints may enjoy full fluid film lubrication with good machining, good fit and a proper lubricant. (C) 1997 Elsevier Science S.A.