Titanium is a phenomenally attractive metal for a wide range of applications. I’s low weight, high strength and corrosion resistance make it the first choice for many aerospace, medical, military and industrial applications, but, and it’s a big but, titanium is an expensive metal, around $20 per lb at the moment (a factor of 20 more than steel and 10 more than aluminum). So if a way could be found to reduce the cost then not only would existing applications benefit but many new ones would almost certainly open up on the back of more affordable material and production costs. The two cost drivers are linked but distinct. Production costs can exacerbate an already high metal cost. For example, in the case of titanium, Metal Bulletin recently wrote that in aerospace applications, the typical “buy-to-fly ratio for titanium mill products is 10 to 1 (10 pounds of material needed to produce a 1-pound part). This is because consumers typically start from plate or rough forgings, but in situations where near final shape can be achieved, massive savings are possible simply be reducing that ratio to 2 to 1 or even better. Metal powders and sintered solids can readily take advantage of metal forming techniques such as metal-injection molding, laser forming, hot- and cold-isostatic pressing, which offer higher yield rates compared with machining from solid blocks according to MB.
So if reductions in material cost and more efficient material forms are major opportunities for expanding demand for titanium applications it is hardly surprising that there has been a flurry of interest about a new titanium production process that after years of development is finally nearing commercial launch. The firm, Metalysis, was born out of research by Cambridge University in the 1990’s and has already amassed 24 patents across 88 countries and although the first semi continuous production cell will only be operational later this year the larger next stage production cell is already under construction for the first half of next year.
The current process for making titanium from ore is the well established Kroll process which comprises multiple stages, operates at high temperatures so it consumes a lot of energy, and produces several unpleasant waste materials. By comparison, Metalysis process operates at temperatures of 800-900 degrees C and produces no harmful by-products. Metalysis estimates that the capital cost of their FFC plant to be less than 25% of a Kroll plant (typically $300m – $500m) and a carbon footprint that is less than 50% of the Kroll process. Essentially crushed and reformed discs of titanium oxide ore are placed into a molten salt bath with a graphite electrode while a current is passed through them. The oxides migrate to the graphite and come off as carbon dioxide while the purified titanium is left behind in a porous form ideal for light crushing and washing prior use. In terms of the product produced, Metalysis titanium (and indeed any one of a host of other metals that can equally well be refined in this way) produces a powder ideally suited to metal forming to near final shape products.
Not surprisingly more than 30 firms have approached Metalysis looking to form joint ventures or license the intellectual property, but they won’t be the only ones following next year’s trials of the new cells. If the trials prove viable, many new opportunities could open up for designers and engineers looking to exploit titanium’s unique properties.