Avaliação da temperatura de sinterização nas propriedades mecânicas na liga Ti-10Nb produzida por tape casting

Abstract

Titanium commonly exhibts a high strength/weight ratio, good corrosion resistance, and can be used over a vast temperature range. The addition of the element niobium, a β phase estabilizer, results in alloys with a low Young’s modulus, high mechanical resistance, and good biocompatibility, due to the stoxic characteristic of this element. However, titanium-based alloys are among the most difficult one’s to produce, requiring affordable alternatives to reduce manufactuing cost. The present work aims the study of titanium-niobium alloys produced by an economically viable technique denominated tape casting, characterizing Ti-10Nb alloy samples sintered at 1100 ◦C, 1200 ◦C and 1300 ◦C Apparent porosity was determined using the Arquimedes method, relative density was evaluated by pycnometry, Vickers microhardness was measured, and the stress-strain ratio was determined through tensile test. The sintering temperature of 1100 ◦C resulted in samples with an inhmogeneous β phase distribution on its microstructure and a high level of porosity whereas the increase in the sintering temperature to 1200 ◦C and 1300 ◦C spawned progressive β phase increase through the growth of continuous layers and densification of the alloys. The reduction in porosity causes an increase in hardness values of the alloy, however the use of a sintering temperature as high as 1300 ◦C caused a reduction in hardness due to grain growth and increase of β phase proportion. The greater β phase homogeneity also promoted lower mechanical strength, observing that the sintering temperature of 1200 ◦C showed better tensile strength results on its samples.