3D Printed titanium: a Game Changer!

3D Printing, or Additive Manufacturing is here to stay and it's no longer a gimmick. I remember when I first started hearing about 3D printing, I was like "What's that??" seeing as I only knew forged billet, rolled sheet and bar, plate and sheet processes. It was like a caveman discovering fire. OK, I should re-phrase that since cavemen developed pretty useful tools and processes. It has become my go-to manufacturing process, but only when it makes sense and only when it provides something unique or innovative that could not be accomplished by traditional means.

Why does 3D printing make sense for titanium though? Traditionally, our favorite material has been very expensive compared to other materials. I recently did a powder cost review comparing AlSi10Mg, which gives a typical tensile strength of about 35 ksi in the printed condition, with a starting price of about $45/kg. Whereas Ti-6Al-4V powder gives a whopping 137 ksi yield strength in the printed condition with an equally whopping cost of $180-250/kg. There must be a trade-off between cost, mechanical properties or some other unique driver.

In aerospace, titanium has always been used for replacing dense materials like steels, with the benefit of halving the density while maintaining almost the same strength (in our world, high strength for titanium is from 180-220 ksi with 200 ksi more common). In medical, titanium has the advantage of being the implantable metallic material has gives absolutely no adverse reactions in the body, due to the tenacious oxide layer which prevents any negative reactions such as allergic responses. Whatever the driving factor is, strength-to-weight advantages or biocompatibility, using 3D printing can allow the production of unique shapes, lattice structures, fine features or thin walls or designs with overhangs or interior channels that would be difficult or impossible to produce otherwise. It is also challenging traditional processes for materials that are difficult to produce by the usual VAR or EB-VAr or even plasma-melting and forging processes (hello gamma titanium alloys!). For those alloys considered brittle and un-forgeable, 3D printing offers a way forward. Not to mention the cost savings in only using as much material that is needed for true net-shape products.

3D printing of titanium is here and it's here to stay!