Smarter 3D printing leads to better parts faster
3D printers could soon produce complex metal and plastic parts better, thanks to new software developed at the University of Michigan that reduces harmful heat buildup in powder bed fusion laser printers.
Called SmartScan, the software demonstrated a 41% improvement in heat distribution and a 47% reduction in warping in a recent study.
It is also likely to speed up the manufacturing process in two ways: by reducing the need for printers to slow down to help with cooling, and by greatly reducing heat-caused defects that need to be corrected after printing.
Laser powder bed fusion is a form of 3D printing used in the aerospace, automotive, and biomedical industries to make parts that are too complex to make with conventional manufacturing. It uses a laser to fuse together layers of metal or plastic powder. But the heat from the laser can build up in the delicate parts being printed, causing warping and other defects.
“This problem becomes even more serious for parts with very thin features,” said Chinedum Okwudire, associate professor of mechanical engineering at UM and corresponding author of the paper in Additive Manufacturing. “The heat doesn’t have a lot of room to spread, so you have to be smart about how you move the laser or your part will warp in really weird ways.”
SmartScan tackles the problem by examining how heat flows through a given room and mapping an optimized scanning sequence to limit heat buildup in a given area. It analyzes the shape of the part and the thermal properties of the material used, including heat transfer by conduction and convection.
Others in the field have experimented with varying print patterns to reduce heat buildup, such as skipping from area to area or alternating between horizontal and vertical scan directions. But Okwudire says SmartScan is the first solution that uses a thermal model to optimally guide the laser to distribute heat more evenly.
“When you put science into it, you can do it in a way that’s better and works for even the most complex parts,” Okwudire said.
To determine the effectiveness of this first version of SmartScan, the researchers used a laser to print an identical pattern on two stainless steel plates. They used the SmartScan process for the first plate and switched to traditional print patterns for the second plate. Prints made with SmartScan were consistently less distorted and had a more even heat distribution during the marking process than other methods.
Based on the results of the experiment, the team is confident that with further research, they will be able to adapt SmartScan to build fully 3D parts. They plan to further improve the software by taking into account the melting of metal or plastic powder in their thermal modeling, as well as allowing active updating of a scan sequence during printing based on temperature measurements observed in real time using an infrared camera.
“The results are very promising and we have received a lot of positive feedback,” said Okwudire, who has started demonstrating the software to industry partners. “We went with a simple model because it works, and it works better than the trial-and-error approaches used today. We wanted to focus in a direction that was practical and really had the chance to make a difference. »
The study was supported by the UM College of Engineering and the Department of Mechanical Engineering. The University of Michigan has filed for patent protection and is seeking partners to bring the technology to market.