Production and Characterization of Ti-Nb Alloys, Using Powders Obtained by HDH Process Aiming the Development of Biomaterials

Abstract

Titanium is a metal that has high melting point 1668 ° C, the boiling point of 3287° C, low density (4.54 g/cm3) and modulus of elasticity around 12.7 MPa x104. However, one of the most important properties is the biocompatibility, which makes this metal to be the most widely used in biomedical. Several alloys were developed using titanium such as the alloy Ti-6Al-4V, however Al and V show toxic characteristics to the organism. The alloy TiNb has been studied to replace the alloy Ti-6Al-4V, because it presents high biocompatibility, low modulus of elasticity, high corrosion resistance and low toxicity. The alloy TiNb can be obtained by conventional melting route or powder metallurgy, where the powders can be obtained by spray drying, chemical reactions and the process of hydrogenation and dehydrogenation (HDH).The hydrogenation is carried out by inserting hydrogen in the structure of Ti and Nb in vacuum at high temperatures, forming a phase extremely fragile called hydride of Ti and Nb, thus enabling the reduction of particle size by milling. Upon heating under vacuum, the hydrogen is extracted to yield the metals Ti and Nb since the hydrogen forms a reversible phase with metals. This work aims the production and characterization of the alloy TiNb where the powders are obtained through the HDH process, varying the concentration of Nb by weight from 10 to 50%.To analyze the morphology and pore size, formation and composition of phases, we used the techniques of microstructural characterization and mechanical by scanning electron microscopy, BET, X-ray diffraction and compression test. The results showed a heterogeneous distribution of Nb in the matrix Ti as well as a decrease in the modulus of elasticity with increase in percentage of Nb.

Microstructures and Mechanical Properties of Ti-Nb Alloy at Different Composition of Nb Produced via Powder Metallurgy Route

“…Furthermore, smaller particles level which can shift sintering efficiency [12]. The lamellar microstructure is believed to be developed from the beta stabilizing element of Nb, clearly the refining of the lamellar as the Nb content increases [13]. It is observed that the lamellar structure for 25 wt% Nb is wider and coarser as compared to 15 wt% Nb.…”

“…Formation of beta phase also deteriorates the mechanical properties of the alloy produced. The reduction in Young's modulus with increase of Nb composition in the alloy due to the appearance of beta phase [14]…”