Design, ultra-precision polishing and measurement of superfinished orthopaedic implants for bio-medical applications: An integrated approach

Superfinished freeform surfaces are vital to prolong the life of orthopaedic implants against corrosion and wear debris. However, the bearing surfaces of knee implants are usually freeform surfaces which are difficult to be designed, fabricated and measured with sub-micrometer form accuracy and surface finish in the nanometer range. This paper presents an integrated approach for supporting design, ultra-precision polishing and measurement of superfinished orthopaedic implants for bio-medical applications. The platform mainly consists of five key modules which include CAD model design module, data exchange module, model-based simulation system, tool path generator, as well as freeform measurement and characterisation module, respectively. A prototype of the integrated platform has been built and the technological merits of the platform have been realised through a series of experimental work. The results show that the form accuracy and surface roughness of the superfinished surfaces can be reduced effectively with the use of the integrated approach.