Identifying defects in 3D printed items is one of the ongoing challenges to be overcome if the technology is to be more widely adopted. This development is very promising.
Small defects in 3D printed metal parts limit their performance and are roadblocks preventing the technology from being more widely used. Researchers at Argonne National Laboratory theorized that the defects stemmed from small voids in the cooled printed metal. The voids (porosity) can make printed components prone to cracking and other failures.
To check their theory, they used a 3D printer with an IR camera, a common option, to film the printing process from above. It monitored and recorded temperature data during the build process. At the same time, a high-powered X-ray from the Advanced Photon Source at Argonne took a side view of the build it was underway. The goal was to use the X-rays to see voids form and correlate that with what was going on thermally on the surface where new metal was being deposited.
Gas turbines are complex components to manufacture, but additive manufacturing has been successfully utilized to accelerate design cycle times, reduce development test times, provide better test data and reduce the overall time to the release of the final component. It also allows for testing to be performed earlier, as early as the concept or preliminary design phases. This means that there is less likelihood that the entire component will have to be redesigned, as problem areas can be detected and eliminated early.
In a recent case study, a Siemens Energy SGT-A05 industrial gas turbine engine line was manufactured, and additive manufacturing was used for aerodynamic development testing within the preliminary design phase for boundary condition definition of new compressor static flow path components.
X-rays reveal more about 3D-printed metal parts as they are being made, and how to improve them
Metal 3D printing could revolutionize manufacturing, but concerns over part quality and certification has kept many industries from jumping into the technology with both feet. From their perspective, the quality and certificate are critical, and essential for parts destined for automotive and aerospace applications.
To improve metal 3D-printed parts, researchers at Lawrence Livermore National Laboratory (LLNL) are examining the complex mechanisms that drive defects and limit part quality. They have also teamed with scientists at the SLAC National Accelerator Laboratory and Ames Laboratory to better understand 3D printing, looking into what leads to defects and how those flaws might be avoided.
When you 3D print something, you expect that the image you see on your computer screen will be perfectly reproduced on the 3D printer. But that’s not always the case, especially when it comes to more complex industrial metal prints. It’s difficult to fully control the material properties that a 3D printed object will have.
“We wrongly assume that what you print will be identical to what was designed,” said Suresh Babu, who holds the Governor’s Chair for Advanced Manufacturing at the University of Tennessee and Oak Ridge National Laboratory (ORNL). “Printing a material involves a very complex temperature profile for the material due to multiple heating, melting, and cooling events that are all interconnected and inherently dependent on one another.”