Effect of different porosities on mechanical properties and ion release of porous NiTi alloy / 医用生物力学

ABSTRACT

Objective To prepare the porous NiTi alloy with good biocompatibility for jaw bone implantation and compare the amount of the nickel ion release from NiTi alloy with TiO2 or HA coatings, respectively. Methods The porous NiTi samples were fabricated by powder metallurgy and the morphological characteristics were observed by metallographic microscope and X ray dispersive spectroscopy (XRD). The elastic modulus and fracture strength of the porous NiTi samples were recorded after the compression test. By sol-gel method, TiO2 or HA coatings were obtained on the porous NiTi samples, and the amount of nickel ion release from the samples was measured at 1，3，7，15 d, respectively. Results The pores were interconnected with the pore size of 50~200 μm and ~50 μm. The porosities of porous NiTi samples ranged from (23.5±5.24)% to (38.8±1.82)%, the elastic modulus from (9.55±0.19) GPa to (4.28±0.32) GPa, the fracture strength from (133±6.75) MPa to (80.5±5.58) MPa (P0.05). Conclusions The mechanical properties of porous NiTi alloy declined with the increase of pore-forming agent and porosity. Coating treatment could effectively inhibit the release of nickel ion from the porous NiTi alloy.