Challenges in the Production of Titanium–based Scaffolds Bio–functionalized with Hydroxyapatite by Powder Metallurgy Technique

Abstract

Recently, titanium and its alloys have remarkable interest for researchers due to their advanced mechanical, surface and biological properties. Researchers are investigating new materials, especially in the field of health, and perhaps material design is the most important criteria that exhibit the low Young’s modulus of bone. Along with these criteria’s most preferred are composite materials reinforced with hydroxyapatite (HA). Porous materials are preferred because they exhibit Young’s modulus close to the bone. The aim of the study, the problems encountered in the production of titanium/hydroxyapatite (Ti/HA) composite scaffolds and the solutions will be emphasized. These are briefly; porogen removal, usage of different sintering furnaces, sintering atmosphere, material thickness, crack formation-propagation as a result of excessive or insufficient pressing pressure, and agglomeration of porogens during mold filling. It has been proven that the use of vertical tube furnaces under the Ar gas atmosphere has successful results compared to the use of horizontal tube furnaces and different atmospheres (vacuum or Ar gas). It has been concluded that in the composite scaffolds that have been successfully produced, micropores are formed as well as macropores, which may result from insufficient neck growth and pressing pressure. In addition, results showed that bi-modal (macro/micro porosity) pore structures may contribute to bone tissue orientation in possible biomaterial use.