Role of heat treatment of hydroxyapatite powder prior to suspension preparation on the suspension flow behavior

Abstract

One of the key issues involved in successfully achieving hydroxyapatite (HA) ceramic body without defects using colloidal processing technique, is the preparation of homogeneously high solid loading HA ceramic suspension. This could be achieved via controlling the HA powder properties. The maximum achievable solid loading suspension from the as received HA powder was found to be 14 vol%. The treatment of the as received powder via heat treatment process play a very versatile role in changing the physical properties of the powder. Owing to these changes, well dispersed high solid loading HA suspensions reaching 57 and 59 vol% were successfully prepared from HA powder heat-treated at 1000 and 1100 °C, respectively. The suspensions prepared from the heat-treated powder was found to have acceptable rheological properties for casting processes in terms of low particle interaction, lower number of floc and floc network and higher fluidity.

Keywords

• Hydroxyapatite
• Colloidal processing
• Rheology
• Shear rate
• Viscosity
• Shear stress