RESUMO
Developing new materials with high strength and ductility, low modulus and high biocompatibility is a continuing demand in the field of surgical implants. Inspired by the high-entropy design philosophy, two medium entropy alloys (MEAs), i.e. equiatomic TiZrHf and equi-weight Ti40Zr20Hf10Nb20Ta10 were designed and their mechanical properties and biocompatibility were assessed. Both the single-phase hexagonal close-packed (HCP) structured TiZrHf alloy and the single-phase body-centered cubic (BCC) structured Ti40Zr20Hf10Nb20Ta10 alloy show high strength-ductility combinations close to commercial Ti-6Al-4V wrought alloy and remarkably lower young's modulus than commercial pure titanium (CP-Ti) and Ti-6Al-4V. From the aspects of adhesion, proliferation, toxicity and related gene expression of human gingival fibroblasts (HGFs), the Ti40Zr20Hf10Nb20Ta10 alloy exhibits distinctively better biocompatibility than that of CP-Ti while the TiZrHf shows only slightly better biocompatibility as compared with CP-Ti. These results indicate that these two ductile MEAs are potential candidates for dental application.
Assuntos
Ligas/química , Materiais Biocompatíveis/química , Implantes Dentários , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Corrosão , Planejamento de Prótese Dentária , Módulo de Elasticidade , Entropia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Resistência à Tração , Titânio/química , Regulação para Cima/efeitos dos fármacosRESUMO
In this work, TC4/TNTZO multi-layered composite as well as TNTZO and TC4 alloys were prepared by direct laser deposition (DLD) to investigate the microstructure, mechanical properties and in vitro bioactivity. The microstructure characterization shows that the multi-layered material is free of cracks and intermetallics while the interface is metallurgically bonded. The fine microstructure was observed in TC4 layer of the TC4/TNTZO multi-layered material, and a large amount of α' martensite exists in the transition zone. Different from the single ß phase cellular arrays in the DLD-ed TNTZO alloy, αâ³ martensite with high volume content formed at the cellular grain boundary in TNTZO zone of DLD-ed TC4/TNTZO. The elastic modulus of the DLD-ed TC4/TNTZO is 64 GPa, decreased about 45% compared to the DLD-ed TC4. The tensile yield strength and elongation along the printing direction are up to 789 MPa and 7%, which are 12% higher than the tensile yield strength of DLD-ed TNTZO and 61% higher than the elongation of DLD-ed TC4 respectively. Moreover, the DLD-ed TC4/TNTZO shows good in vitro bioactivity. The TC4/TNTZO multi-layered composite fabricated by DLD can be regarded as a potential candidate to integrate the advantages of the two Ti-base alloys for application in the biomedical field.