Presintered Titanium-Hydroxyapatite Composite Fabricated via PIM Route

Abstract

Ti6Al4V-HA composites have been recognized for their potential for biomedical implantation purposes. In the present study, Ti6Al4V-HA composites were fabricated by Powder Injection Molding (PIM) route. Ti6Al4V-HA feedstock at a ratio of 87:13 vol.% was prepared by using a binder system consisting of palm stearin (PS) and polyethylene (PE). The Critical Powder Volume Percentage (CPVP) value for Ti6Al4V-HA was 68 vol.%. Ti6Al4V-HA feedstock was developed at 66 vol.% powder loading. Ti6Al4V-HA feedstock showed pseudoplastic behaviour with a low viscosity and low activation energy of flow and was successfully injected into a tensile bar shape. The debinding process involved a solvent and thermal debinding operation. The debonded parts were sintered at 1300 °C, and the influence of the presintering stage on the physical and mechanical properties of the sintered parts was investigated. It was proven that the presintering stage was able to restrain the transformation of Ti6Al4V into Ti3Al (α2) as well as the decomposition of HA. These are key findings ideas for the designing of sintering parameters, where the decomposition of HA becoming the main problem in the sintering of Ti6Al4V-HA composites at a high temperature. The obtained results also showed that the sintered parts had a porous structure, which looked promising for their use in biomedical implantations. purposes.

High strength bioinspired calcium phosphate-based material for bone repair applications

“…For this reason, it is necessary to construct synergistic mechanisms of strengthening to control and regulate the composites microstructure in order to improve their biological activity [24,25] and properties such as hardness [26,27], compressive [20,28] and flexural strength [26,29]. Unfortunately, the current literature data on the mechanical strength of hydroxyapatite composites for bone repair applications is limited and very broad [30][31][32][33][34][35][36][37][38][39]. Therefore, this work concentrates on the development of high strength hydroxyapatite-based materials from commercial hydroxyapatite and seashell waste.…”

Sintering Analysis of Porous Ti/xTa Alloys Fabricated from Elemental Powders

“…Most of the TMCs are developed to improve the mechanical properties, however, for biomedical applications this is not desirable. On the other hand, TMCs reinforced with hydroxyapatite were studied to successfully improve the osseointegration properties of the titanium and its alloys [ 13 ]. Notwithstanding the benefits of TMCs, their mechanical properties remain high in comparison to those of human bones.…”

“…The lower elastic modulus in β -Ti alloys compared to stainless steel is a positive factor in reducing bone resorption [ 17 ]. β -Ti alloys have lower elastic modulus and present better formability and corrosion resistance than the α -Ti and α + β alloys [ 13 , 18 , 19 ]. Another advantage of β -Ti alloys is the possibility of the martensitic type transformations β → α′ or β → α″ between their metastable phases [ 13 , 20 ].…”

“…β -Ti alloys have lower elastic modulus and present better formability and corrosion resistance than the α -Ti and α + β alloys [ 13 , 18 , 19 ]. Another advantage of β -Ti alloys is the possibility of the martensitic type transformations β → α′ or β → α″ between their metastable phases [ 13 , 20 ]. These alloys show low elastic modulus, shape memory behavior and super elasticity, which favors their applications in the biomedical field [ 9 ].…”