REDUCTION OF STATIC FRICTION BETWEEN SURFACES OF TI-6AL-4V AND BETWEEN SURFACES OF TI-6AL-4V AND AL-7075

In a mechanical application where there were strict demands for precision and reliability, it was required to minimize the static friction between components of Ti-6Al-4V and also between components of Ti-6Al-4V and Al-7075. Different test samples of the materials of interest were ion implanted with high doses of carbon, nitrogen and oxygen ions. Static friction measurements were made in unlubricated conditions. It was found that the coefficient of static friction between the surfaces of interest could be most effectively reduced by implanting both surfaces in contact with high doses of carbon ions. The coefficient of static friction between Ti-6Al-4V surfaces was reduced from 0.38 to 0.19 and the coefficient of static friction between Ti-6Al-4V and Al-7075 was reduced from 0.32 to 0. 1 7. These values compare well with the friction coefficients observed when the substrates were coated with low friction coatings.