Papers by Author: C.R.M. Afonso

Abstract: The high cost of processing of Ti alloys is an important limitation to their utilization in a number of applications. An approach to overcome such difficulties would be their processing by precision casting. The purpose of this work is to evaluate the centrifugal casting process of Ti-Cu and Ti-Nb alloys, analysing the influence of alloying element type and content in the obtained microstructure. Samples with different compositions were prepared in arc furnace with non-consumable tungsten electrode and water-cooled copper hearth under high purity argon atmosphere and cast in a copper mould. Microstructures were analysed by SEM, characterized by EDS and X-ray diffraction. Vickers hardness measurements helped the analysis of phases.

Abstract: Titanium alloys comprise a versatile class of biomedical materials. Among them, β- titanium alloy is one of the most promising metallic materials for biomaterial applications thanks to their high mechanical strength, good corrosion resistance and excellent biocompatibility. This study purported to analyze the phase stability in Ti-Nb alloys, evaluating the influence of the Nb content on the microstructure obtained under different heat treatment conditions. To this end, Ti-Nb alloys containing 5 to 35% (wt.%) of Nb were prepared and evaluated. The samples were arc melted and characterized using optical microscopy, transmission electron microscopy and X-ray diffraction. Young’s modulus was evaluated primarily by acoustic techniques.