New 3D metal printers work with LED light sources

Researchers at Graz University of Technology have created a new type of 3D printer that uses LEDs instead of laser sources for rapid prototyping manufacturing of metal parts. This new 3D printer can optimize the construction time, metal powder consumption, equipment cost and post-processing of 3D metal printing. At present, the development team has applied for a technical patent for this 3D printer.

The technology used by the 3D printer is said to be similar to selective laser or electron beam melting technology. The process uses molten metal powder, which is then stacked to form a part. This new technology is called Selective LED-based Melting (SLEDM), which eliminates two core problems of powder bed-based manufacturing processes.

These two core issues include the time-consuming production of high-volume metal parts and time-consuming manual rework. SLEDM uses high-performance LED beams, which is characterized by LEDs specially modified by lighting expert Preworks, and is equipped with a complex lens system that can focus the diameter of the LED beam.

The lens system allows the beam to vary between 0.05 and 20 mm during the melting process. The changeable LED focus allows a larger volume to be melted in a unit of time without the need for internal filamentary structures. The absence of an internal thread-like structure reduces the production time of components and fuel cells or medical technology by 20 times.

The process also means that the components are assembled from top to bottom, exposing the components and reducing the required powder to a minimum. The necessary post-processing can be performed during the printing process. At present, the printer is being used to produce bioabsorbable metal implants, such as screws made of magnesium alloy for the treatment of fractures. Those implants will dissolve into the body after the fracture grows, and there is no need to perform a second surgery to remove the screw.