Nano Finishing of HDPE/Al2O3/HAp Ternary Composite Based Acetabular Socket using Polymer Rheological Abrasive Semisolid Medium

Abstract

Acetabular socket is one of the important parts of the hip joint. The surface roughness in the acetabular socket decides the friction and wear during the motion of the human. Low surface roughness in the acetabular socket gives free motion of hip joint as well as high joint life. Nano surface roughness on the inner surface of acetabular socket also reduce the particles generation during the dynamic motion between hip joint head and socket as well as increases the bearing area between two components. Complete metal or ceramics leads to brittle fracture on extreme loads as well as sound generation when there is dynamic motion between them. Thus, polymer-ceramic composites came into existence. In the current work, high density polyethylene/Alumina/Hydroxyapatite (HDPE/Al2O3/HAp) based polymer ceramic composite acetabular socket is fabricated using spark plasma sintering. Finishing of this polymer-ceramic composite is big challenge as hardness variation between polymer and ceramic is too high. So, conventional finishing processes (Ex. Grinding etc.) are not suitable
because it exerts high finishing forces which might permanently damage the component. Hence, in the current research work, HDPE/Al2O3/HAp based polymer-ceramic acetabular socket is finished to nano scale using polymer rheological abrasive semisolid medium (medium). Since this medium is semi solid to liquid based viscoelastic in nature and exert low
finishing forces (<5 N). This polymer rheological abrasive semisolid medium can able to finish the acetabular socket with average initial surface roughness of about 4.00 μm to 0.45 μm. Thus it enhances the comfort and life of acetabular socket.

Keywords: Bioimplants, Nanobiotechnolohy, Polymers