Metal process

The additive manufacturing process combines powder and resin printing

The illustration shows a 3D printed sample with an inner cylindrical region made of TPU powder and an outer region of SLA resin. The print has 30 layers. a) Top view of the inner and outer region. b) Profile view of the nested cylinder. c) Sliced ​​sample profile view.

Researchers have developed a method that can print components from SLS (selective laser sintering) powders and SLA (stereolithography) resins, according to a research paper posted on the Science Direct website.

The bi-material approach allows users to couple the strength of SLS parts with the surface finish of SLA components, write the researchers, Columbia University PhD candidate John Whitehead and Columbia professor Hod Lipson.

The article, “Multi-Process Printing Combining Powder and Resin Based Additive Manufacturing,” explains that both SLA and SLS are laser-based technologies. However, liquid resins are used for the SLA process while SLS processes build parts from particles of molten materials, including metal alloys and some polymers.

The new process could be used, for example, to print conductive metal channels in a non-conductive resin part.

“Traditionally, users have been forced to select a single AM ​​machine that uses a single printing process with a single type of material to produce a given part, and then make adjustments to the object printed with a secondary material by post-processing,” the authors write. “It can be inaccurate or time-consuming, depending on the fitting method used.”