Hybrid microwave sintering of blended elemental Ti alloys

Abstract

Powder metallurgy, and in particular the blending elemental approach, is a recognised way to reduce the processing cost of titanium-based materials for their wider industrial uptake. Microwave sintering is claimed to be a faster sintering process that could contribute to the cost reduction. In this study hybrid microwave sintering was used to consolidate cold pressed blended elemental alpha + beta (i.e. Ti-6Al-4V and the low-cost Ti-5Fe), metastable beta Ti-5Al-5Mo-5V-3Cr titanium alloys as well as hydride-dehydride Ti. It is found that densification is achieved at low sintering temperatures and short dwell time but proportionally higher temperatures and longer sintering times are required for the homogenisation of the chemical composition of more heavily alloyed materials. Similarly to vacuum sintering, for most of the materials relative density around 94–95% are obtained, but no faster sintering at maximum temperature was perceived. The mechanical properties increase along with the sintering parameter obtaining values comparable to the respective wrought and/or powder metallurgy counterparts.