Static coefficient of friction between Ti-6Al-4V and PMMA for cemented hipand knee implants

The static coefficient of friction between Ti-6Al-4V and PMMA was determine d experimentally. A microtopographic surface analysis of the Ti-6Al-4V and PMMA specimens used in the experiments was performed to characterize the su rfaces. The coefficient of friction between Ti6Al-4V and PMMA in both dry a nd wet conditions, using both Ringer's solution and bovine serum, was deter mined by the standard inclined plane test, following the ASTM 4516-91 metho d, and by a prototype computerized sliding friction tester. The effects of surface roughness and of contact pressure on the coefficient of friction al so have been investigated. Tests were performed at 26 degreesC and at body temperature of 37 degreesC. Considering all the tests, the overall range of the mean coefficients of friction varied between 0.17 and 0.32 in dry or w et conditions. For the same surface roughness in contact, in general the co efficient of friction using Ringer's solution was slightly lower than it wa s in dry conditions whereas bovine serum had a very high surface tension, w hich significantly increased the static coefficient of friction. (C) 2001 J ohn Wiley & Sons, Inc.