Novel and Emerging Routes for Titanium Powder Production - An Overview

Abstract

As the adoption of components fabricated via titanium powder metallurgy (PM) techniques becomes more prevalent, and projected to increase at a substantial rate over the next decade, especially in the field of additive manufacturing (AM), there is a necessity to increase titanium powder production capacity from the current annual level of ca. 6000 tonnes per annum. At present a well-documented barrier restricting this widespread implementation, is the inherently high cost of the feedstock, an issue which to date has been neglected to some degree, at the expense of developing the individual powder metallurgy routes. The scope of this overview therefore is to provide an insight of both established and novel methods of titanium powder production, as potential opportunities to satisfy this growing demand. Particular emphasis will focus on Metalysis, a company founded to commercialize an innovative electrochemical approach for the synthesis of metals and alloys from their respective oxides, where the ability to generate titanium eloquently demonstrates the extent of its capabilities.The patented Metalysis technology, exploiting the FFC® Cambridge process, lends itself to producing alloys and intermetallics, where Ti-6Al-4V provides a prime example of this. Furthermore, as electrolysis occurs solely in the solid state, issues pertaining to segregation due to dissimilar densities and melting points are avoided. It is possible to tailor both the average particle diameter and size distribution of the product targeted powder metallurgy (PM) applications, based upon appropriate selection of the feed. The attraction of this strategy is that the steps associated with conventional metal powder synthesis are circumvented, resulting in a significant cost reduction. Moreover it has recently been revealed that titanium can be produced directly from naturally occurring ore (beach sand) and synthetic rutile, with the ensuing product presenting itself as an inexpensive and abundant feedstock for additive manufacturing (AM). This represents a paradigm shift in the availability of consumables for the 3D printing market.