Researchers at Saarland University’s Chair for Metallic Materials have developed a new class of amorphous metals, titanium-sulfur alloys, said to be very light and almost twice as strong as conventional titanium-based metals.
Heraeus, which remains a family-owned business, provided financial and logistical support through its Amorphous Metals startup and has secured the usage rights for most of the new alloys (patent pending), adding to its growing expertise in working with metal alloys. Dr Hans Jürgen Wachter, who heads up the Amorphous Metals division, explained: “The market is clamoring for new materials with new material properties. We can melt, roll, and additively manufacture amorphous metals. Over the coming months, we aim to develop new amorphous alloys, build components in cooperation with various partners from the industry and research, and tap into new areas of application.”
Amorphous metals are metallic glasses with properties that resemble those of frozen liquids. They are cooled down from the smelter very rapidly, preventing ordered structures from forming as they reach a solid state so that they become amorphous, like a glass. This in turn gives them a variety of previously incompatible characteristics and has potential for numerous high-tech applications. The materials are shock-absorbent and scratch-resistant, and they also have very good spring characteristics—interesting for durable injection nozzle diaphragms, as lighter shatter-proof casings for smartphones, or as sharp, durable scalpels and minimally invasive instruments.
The key component to this new alloy is sulfur. Oliver Gross, one of the university’s doctoral candidates, says: “Nobody had considered sulfur for 20 or 30 years, because it had never worked in any experiment.” But the group tested sulfur as an additive to various metals, initially finding a workable alloy with palladium, nickel and sulfur that had good properties, before trying titanium. It took a further 250 experiments to find the right balance in the combination of titanium and sulfur.
The obvious application will be the aerospace industry where the combined strength and light weight will be useful for the production of light, small components.