2014 年 84 巻 5 号 p. 557-565
The purpose of this study is to achieve zero wear of UHMWPE by maintaining a good lubricating film to the artificial joint sliding surface between the femoral head and the socket components.
In order to keep the fluid film lubrication constantly between the sliding components, the processing technology of the femoral ball with the high sphericity can be required. So, the precision machining technique by the Die-Sinking EDM (Electric Discharge Machinery) and the spherical grinding machine was developed to improve the femoral head sphericity.
The main results obtained are as follows:
1) The sphericity of the femoral head has been improved by the EDM and the ball grinding machines, and the sphericity of 0.75μm was achieved to processing of the Ti-13Zr-13Nb femoral head ball.
2) The sphericity of the socket was 8.73μm, and by being used together with the femoral ball mentioned above, we could add the ability to keep the fluid film lubrication to the artificial hip joints.