Metal-Driven Autoantifriction Function of Artificial Hip Joint

Area of Science:

• Biomaterials Engineering
• Tribology
• Surface Science

Background:

• Artificial hip joint prostheses have a limited service life of 10-15 years.
• Improving the friction coefficient and wear resistance of metallic femoral heads is crucial for extending prosthesis longevity, especially in young patients.

Purpose of the Study:

• To develop and evaluate a novel Cu-doped titanium nitride (TiN_X -Cu) film with autoantifriction properties.
• To enhance the lifespan of artificial hip joints by reducing friction and improving wear resistance.

Main Methods:

• Magnetron sputtering was used to deposit a TiN_X -Cu film onto a CoCrMo alloy.
• The tribological performance of the Al₂ O₃ /TiN_X -Cu tribopair was investigated in a protein-containing lubricating medium.

Main Results:

• The Cu in the TiN_X -Cu film binds to proteins, forming a stable surface layer.
• Shear stress between the tribopair decomposes adsorbed proteins into hydrocarbon fragments.
• Copper catalysis and shear stress synergistically convert fragments into graphite-like carbon tribofilms, reducing friction and enhancing wear resistance.

Conclusions:

• The developed TiN_X -Cu film exhibits 'autoantifriction' properties by generating antifriction tribofilms.
• This technology holds promise for prolonging the lifespan of prosthetic devices, including artificial hip joints.