Résumé | An effective approach for minimizing the stress-shielding effect of orthopedic implants is to use implant materials with bone-matching modulus. Ti/polymer composites formed by infiltration of a polymer into porous Ti preforms are considered promising for such applications due to their tailorable elastic modulus, good corrosion resistance and potentially high mechanical performance. In this work, a fabrication process has been developed to produce porous Ti preforms from titanium hydride powders. The sintering kinetics studies showed that titanium obtained from titanium hydride had a lower sintering activation energy of 85± kJ/mol, as compared to 93±3 kJ/mol for normal titanium powders. The lower sintering activation energy resulting from the fresh and clean (non-oxide covered) particle surfaces after dehydration has led to faster sintering (lower sintering temperature) for titanium powders derived from titanium hydride. The fabrication process using titanium hydride offers a low production cost and low interstitial contaminants (oxygen, nitrogen, carbon, and hydrogen). High density polyethylene (HDPE) was infiltrated into the porous titanium preforms produced from titanium hydride to fabricate Ti/HDPE composites. The relation of flexural modulus and flexural strength of the composites with the HDPE volume fraction was established. It was found that Ti/HDPE composites with 30-38% volume of HDPE showed a similar flexural modulus to the of the human bone, while the bending strength is higher than the of human bone. |
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