Engineering news
An inter-university team from the US made the materials breakthrough, which they claimed creates better stainless steel than traditional manufacturing, as they optimised 3D-printing of metal structures with computer modelling and microscopic experimentation.
The result, said the researchers from Lawrence Livermore National Laboratory (LLNL), Ames National Laboratory, Georgia Tech University and Oregon State University, is stainless steel with an “unparalleled combination” of high strength and high ductility – how much it can be stretched or hammered thin without breaking.
The two characteristics were traditionally thought to be mutually exclusive, but through “tuning” the metal’s microscopic grain-like structure, the team found the resulting material was stronger yet more ductile than traditional stainless steel. “We didn't set out to make something better than traditional manufacturing; it just worked out that way,” claimed LLNL researcher Alex Hamza.
The team claimed their work could “open the floodgates” to widespread 3D-printing of stainless steel components, particularly in the aerospace, automotive and oil and gas industries, where strong and tough materials are needed to tolerate extreme forces in extreme environments.
“If the traditional strength-ductility trade-off boundary can be manipulated and moved through 3D printing as suggested by the research, it may allow for materials… to be utilised in areas where before they would not have been considered,” Josh Dugdale from the Manufacturing Technologies Association told Professional Engineering.
The work could have wider application if successfully adapted for other types of metals, technical manager Dugdale suggested. “It would be interesting to see if they are able to apply the same methodology to other metals to see if they can achieve the same kind of benefits,” he said. “It is really good news for additive technology and should help towards encouraging further adoption… by industry.”
Laser melting of metal powders in 3D-printing processes often creates porous structures which degrade and fracture easily. However, the US collaboration used extensive experimentation and computer modelling over several years to manipulate cell-like structures in the metals. The researchers discovered the cells, “like stained glass windows,” after printing thin plates of stainless steel with two different laser machines. They then realised they could “tune” the cells, which alter the overall mechanical properties of the metal.
The research was published in Nature Materials.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.