Development of a  -type Ti–12Mo–5Ta alloy for biomedical applications: cytocompatibility and metallurgical aspects

Abstract

Ti-based biocompatible alloys are especially used for replacing failed hard tissue. Some of the most actively investigated materials for medical implants are the beta-Ti alloys, as they have a low elastic modulus (to inhibit bone resorption). They are alloyed with elements such as Nb, Ta, Zr, Mo, and Fe. We have prepared a new beta-Ti alloy that combines Ti with the non-toxic elements Ta and Mo using a vacuum arc-melting furnace and then annealed at 950 degrees C for one hour. The alloy was finally quenched in water at room temperature. The Ti-12Mo-5Ta alloy was characterised by X-ray diffraction, optical microscopy, SEM and EDS and found to have a body-centred-cubic structure (beta-type). It had a lower Young's modulus (about 74 GPa) than the classical alpha/beta Ti-6Al-4V alloy (120 GPa), while its Vickers hardness remained very high (about 303 HV). This makes it a good compromise for a use as a bone substitute. The cytocompatibility of samples of Ti-12Mo-5Ta and Ti-6Al-4V titanium alloys with various surface roughnesses was assessed in vitro using organotypic cultures of bone tissue and quantitative analyses of cell migration, proliferation and adhesion. Mechanically polished surfaces were prepared to produce unorientated residual polished grooves and cells grew to a particularly high density on the smoother Ti-12Mo-5Ta surface tested.

Investigation of processing effects on the corrosion resistance of Ti20Mo alloy in saline solutions

“…Moreover, alloying titanium with Mo β-stabilizers improves the corrosion resistance [4][5][6][7][8][9][10], in addition to adequate mechanical compatibility and good cytocompatibility [11][12][13][14][15][16] despite one controversial report [17]. Unfortunately, titanium and molybdenum are difficult to alloy through a conventional melting-casting process due to the big difference in melting point and specific gravity between the two metals.…”

Low-Modulus Ti Alloys Suitable for Rods in Spinal Fixation Devices

“…Moreover, Mo is less toxic than Al and V [1]. Many studies have demonstrated the excellent mechanical compatibility and good cytocompatibility of Ti alloys containing Mo, such as Ti-Mo, Ti-Mo-Ta, and Ti-Mo-Zr-Fe [12][13][14][15][16][17]. Karthega et al [18] reported that Ti-15Mo exhibits corrosion resistance similar to that of TNTZ in Hank's solution.…”

RESISTÊNCIA À CORROSÃO DE LIGAS Ti-35Nb-xTa EM SOLUÇÃO DE NaCl 0,9%

“…Entre os materiais metálicos convencionais para tal emprego podem ser citados o aço inoxidável ASTM F138, a liga à base de Co-Cr-Mo, e a liga Ti-6Al-4V [2][3][4][5][6][7][8][9][10], sendo este última a mais apropriada para implantes femorais devido à sua alta resistência mecânica, menor módulo de elasticidade e excelente resistência à corrosão [6,7,9,10]. No entanto, nos últimos anos a literatura vem registrando diversos estudos sobre a toxidade dos elementos de liga e a reabsorção óssea como fatores que causam a falha de implantes [7,[9][10][11][12][13][14][15]. Essas preocupações têm estimulado o estudo de novas ligas de titânio que apresentem elementos biocompatíveis e possuam baixos módulos de elasticidade a fim de minimizar a reabsorção óssea, além de oferecer uma elevada resistência à corrosão, uma vez que tais materiais serão usados em meio fisiológico, o qual é bastante agressivo aos metais presentes na composição da liga [3,16].…”