University of Sheffield's diode area melting process could pave way for faster 3D printing technologies

Researchers at the UK’s University of Sheffield have invented a 3D printing process called diode area melting (DAM) that they believe is set to change the way parts are produced.

Laser melting systems are increasingly being used in high-value sectors—such as aerospace and automotive—to produce metal and plastic parts layer-by-layer from powders. However, these systems rely on a mirror to deflect a single laser, thus prohibiting speed.

The DAM process instead uses a number of laser diodes to melt large areas in parallel. These laser diodes can be switched on and off as they move across the powder bed, making the process faster as well as more energy efficient. 

The research challenges the 3D printing industry’s long-held belief that laser diodes are unable to achieve sufficient melting points owing to their low power and poor beam quality.

A key factor in the success of the DAM process has been the use of shorter, 808 nanometer wavelength arrays. This has resulted in increased absorption of the individually collimated and focused beams, allowing for melting points in excess of 1,400 degrees centigrade (2,552˚F) to be reached in just a few milliseconds. Using the DAM process, the researchers have managed to produce fully dense, 17-4 PH stainless steel parts.

The inventors of the DAM process—Dr. Kristian Groom, from the department of electronic and electrical engineering, and Dr. Kamran Mumtaz, from the department of mechanical engineering—intend to continue investigating laser interaction, although they also have plans to scale up the DAM process and extend its use to polymer processing.

The research team is of the opinion that it may even be possible to combine wavelength-targeted processing for a wide range of materials in a single machine. 

The DAM process research has been supported by proof-of-concept funding from an Engineering and Physical Sciences Research Council (EPSRC) allocated Impact Acceleration Account (IAA) grant.

Website: www.sheffield.ac.uk/engineering