Wear resistant ball and socket joint

The present invention relates to base ball wear particularly suitable for a prosthesis. More specifically, construction of the joint includes a relatively pliant socket material, while the ball has a hard, rigid surface. Unlike many prior art joints employing polymer liners, the relatively pliant material is selected from a material which is usually categorized as hard, such as metals. The benefit obtained by relative compliance is that when forces are imposed urging the ball against the socket, one contact surface yields and conforms to the other contact surface. Mutual contact area is thereby maximized, thus reducing maximal loading at any one localized point. When maximal localized loads are minimized, wear is mitigated.
A crucial combination of characteristics of the respective materials include specified values of surface hardness, tensile strength, smoothness, and breaking stress. Materials forming the contact surfaces are selected to further include biocompatibility, lack of cold flow, and susceptibility to advantageous forming techniques such as isostatic forming, rolling, and machining.