EPFL scientists have developed a new laser 3D printing technique to eliminate cracks in 3D printed metal components.
According to the scientists, the new method paves way for metal components offering unprecedented resistance to high temperature, damage and corrosion.
This could ultimately benefit applications ranging from aerospace to power-generating turbines.
Manufacturers currently use a technique called Selective Laser Melting (SLM) to 3D print metal components.
With SLM, a powerful laser melts and fuses metallic powders together, gradually building a 3D component layer by layer.
Any remaining powder is removed at the end of the process. However, some metals and alloys cannot withstand the high temperature variations that SLM involves, causing them to crack.
Now researchers at EPFL’s Laboratory of Thermomechanical Metallurgy (LMTM), have developed a new method that involves applying a second laser treatment every few layers during the building phase.
Known as Laser Shock Peening (LSP), the new method heals cracks on the fly during the 3D printing process.
LSP works by periodically directing high-intensity laser pulses on the component under construction. It acts as a sort of high-energy photonic ‘hammer,’ sending shock waves through the material.
According to the team, this dramatically reduces cracking and produces metal components with unprecedented resistance to high temperature, damage and corrosion.
They contend that the patented technique can be used to manufacture new power-generating turbine blades or key aircraft components.
The technique has so far eliminated up to 95% of cracking normally observed in a nickel-based superalloy.
The scientists are now planning to apply the method to other crack-sensitive alloys:
“Laser Shock Peening is normally reserved for surface treatments,” explains team lead Roland Logé. “But in our case, it has become a bulk treatment, in that it operates in 3D within the material itself.”
“This hybrid 3D printing method has applications that go way beyond eliminating cracks. We’re only just beginning to understand its full potential.”
Image and content: iStock/EPFL