Mechanical Properties of Dense Artificial Bone Fabricated by Powder Processing

Abstract

Osseointegration and osteoconduction are essentials for artificial bone tissue production. Hydroxyapatite has been extensively used in orthopedic application due to its similar composition with bone. It is a highly biocompatible calcium-phosphate based bioceramic which could be shaped into bone like structure with powder processing techniques. Gradually changing porosity pattern of bone maintains both ease of transmission of bodily fluids and structural strength. Due to fracture type, in some instances bone tissue could not be recoverable and aligning large bone fractals requires dense bone tissue to place fixation apparatus. In this study, the aim is to produce a dense hydroxyapatite artificial bone and the effects of sintering duration and temperature were investigated. Metal ion doped calcium phosphates in hydroxyapatite form (<100nm) were used as powder. Two different types of Polyvinyl alcohol (PVA, with molecular weights of 10000 and 60000g/mol) were used as plasticizers to obtain strong green samples. The samples were sintered between 1000°C to 1200°C for 60-300 min. Hardness and compression test were performed to observe effect of the process parameters. From the SEM images and density measurements, highly dense samples were fabricated at 1200°C for 120 minutes. Compressive strength and hardness were enhanced up to 71 MPa and 4.5 GPa, respectively.