Using lasers to 'heat and beat' 3D-printed metals

Scientists from Nanyang Technological University, Singapore (NTU Singapore) and the University of Cambridge have developed a new method that can make customised 3D-printed metal parts containing different properties — such as having some regions of the metal stronger than others. The new technique uses 3D-printing steps, and unlike traditional metal manufacturing processes, it does not require additional raw materials, mechanical treatment or drastic machining processes to achieve a similar effect, such as coating the metal with a different material.

Besides designing a 3D-printed metal part with different strength levels, the new process should also allow manufacturers to design a part with other features, such as differing levels of electrical conductivity or corrosion resistance in the same metal. The researchers, led by Professor Gao Huajian from NTU Singapore, took inspiration from ‘heating and beating’ methods similar to the steps originally involved in blacksmithing to develop the new process.

This led them to combine materials science and mechanical engineering principles to apply the 3D-printing techniques usually used to remove and prevent defects in printed metals to alter microscopic structures in the metals. The novel method also lets manufacturers determine what type of internal microstructure they want — and thus the type of property — and precisely where it can be formed in the metal. This improves on traditional means that do not have such fine control.

Gao said the new method paves the way for designing high-performance metal parts with microstructures that can be fine-tuned to adjust the parts’ mechanical and functional properties. The method also allows them to be shaped in complex ways with 3D printing.

The research findings were detailed in a paper published in the journal Nature Communications.

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