These values were lower than those obtained for pure UHMWPE
pin sliding over a hard counter surface (stainless steel 316L) coated
with TiN and Micronite performed under a lower contact pressure
[5] and to those reported by Ge et al. [10] for an UHMWPE
implanted with nitrogen ions which exhibited friction coefficient
of 0.26, 0.18 and 0.16 in dry friction with a load of 5 N.