Norsk Titanium & QuesTek test additive titanium alloy

Building upon the collaboration announced at Farnborough in July 2018, Norsk Titanium has successfully printed QuesTek's custom titanium wire in support of initial material properties testing.

QuesTek thoroughly evaluated the microstructure and measured the properties in several heat-treated conditions including various combinations of stress relief and solution treatment. Superior performance versus Ti-6-4 has been demonstrated.

The highest performance condition was a basic one-hour solution treatment where an average Ultimate Tensile Strength (UTS) of 147 ksi and an average elongation of 18% was measured. This represents an increase in both strength and elongation, while maintaining fatigue performance, over standard Ti-6Al-4V.

"QuesTek's high-performance titanium alloy provides an opportunity for Norsk's customers to optimize components printed with Norsk Titanium's RPD process and opens doors for new applications," said Norsk Chief Technology Officer Carl Johnson.

The typical Ti-6Al-4V microstructure shows an α/β structure consisting of packets of parallel α laths, while the QuesTek's titanium alloy is an α' martensitic structure with a "basket weave" morphology of martensitically-formed α' plates. The non-parallel and refined nature of the plate martensite structure in QuesTek's alloy is believed to be responsible for the increased strength and toughness compared to coarser, parallel α laths of Ti-6Al-4V. QuesTek's alloying element contributes an enhanced response to heat treatment, beneficial for both strength and elongation properties.

Norsk and QuesTek plan to perform additional testing, while working with aircraft and propulsion manufacturers on the improved business case the new alloy affords.