Direct laser melting also called Selective laser melting is a rapid prototyping, additive manufacturing, 3D printing technique. It is intended to utilize a high-powered density laser to melt and fuse metallic powders. However, the technique is likely to experience weld-cracking.
Experts at the Laboratory of Thermomechanical Metallurgy of EPFL have created a new laser 3D printing method. The method works through the application of another laser therapy each a few layers in the construction stage.
This significantly lessens cracking and generates metal elements with unusual resistance from damage, corrosion, and high temperatures. Scientists said that the technique could have applications in making new power-generating turbine blades or key aircraft parts.
In experiments, experts discovered that the method is potentially able to do away with 95% of fracturing. The cracking is usually seen in a nickel-based superalloy. The scientists utilized a method called laser shock peening. The method is also called LSP and they used it to treat cracks on the fly in the 3D printing procedure.
In the procedure, a solid-state laser beam is pulsed on a metallic surface. After that, shock waves are then produced moving all through the component under construction. This serves as high-energy photonic “hammer.” It sends shock waves via the material.
The technique includes two lasers. The first one melts the metallic powders and heats the fused material. The second one produces stresses in the element in targeted areas to gets rid of breaks.
“Laser shock peening is normally reserved for surface treatments. But in our case, it has become a bulk treatment, in that it operates in 3D within the material itself.” Roland Logé said at the School of Engineering.
“Several 3D-printing companies have expressed an interest in the new technique. This hybrid 3D-printing method has applications that go way beyond eliminating cracks. We’re only just beginning to understand its full potential.” He added.