A new 3D printing technique creates stronger stainless steel Watch Now

Video: New 3D printing technique creates stronger stainless steel

Researchers have developed a way to 3D print stainless steel that triples the strength of the material.

3D printing has been used in everything from printing meat substitutes to vehicle components and has also prompted entirely new business models based on blueprint sharing and outsourced printing services.

Companies including GE, Siemens, and HP are all placing their bets on the future of this manufacturing process, and while 3D printing is currently reserved most often for weaker materials such as paper or plastic, metal is also of interest.

HP recently hinted at the 2018 release of a platform designed to "transform [3D metal printing] into more mainstream, high-volume production," and as a research team from the Lawrence Livermore National Laboratory in California have now demonstrated, the future of our metal products can be improved no end by 3D printing methods.

In collaboration with engineers from Ames National Laboratory, Georgia Tech, and Oregon State, the team was able to print a low-carbon kind of steel dubbed 316L, which is strong enough to be used for military and marine applications.

While describing their methods in the journal Nature Materials, the team said that the techniques used to print the steel resulted in improved strength and ductility in comparison to the traditional material.

Laser sintering is usually used in 3D printing to craft solid objects and this process -- which relies on metal powder, melting, and fusing -- may be able to create intricate pieces, but will often lack strength.

As noted by Science, this method does not create the microstructure needed for objects required to undergo stress.

However, the team's new method allows 316L to be created through a regular printer, but it also controls the heat and fusing to prevent material becoming porous and weak, lowering the risk of fracturing.

"This microstructure we developed breaks the traditional strength-ductility tradeoff barrier," said LLNL materials scientist and lead author Morris Wang. "For steel, you want to make it stronger, but you lose ductility essentially; you can't have both. But with 3D printing, we're able to move this boundary beyond the current tradeoff."

The engineers experimented with printing steel through different laser powders and thin plates of metal. As a result, the strength of the stainless steel tripled under certain conditions -- but this was a surprise to the scientists.

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"When you additively manufacture 316L it creates an interesting grain structure, sort of like a stained-glass window," LLNL scientist Alex Hamza commented. "The grains are not very small, but the cellular structures and other defects inside the grains that are commonly seen in welding seem to be controlling the properties."

"This was the discovery. We didn't set out to make something better than traditional manufacturing; it just worked out that way," Hamza added.

The applications of the research are vast. In the future, printing stainless steel components and objects could enhance the strength of materials used in everything from space to the military and aviation.

The next step for the team is to use high-performance computing to predict the performance of future stainless steel and create models that can be used to modifying underlying infrastructures with the potential of exploring other metal alloys.

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