New laser technique can produce parts with intricate features and complex internal characteristics by consecutively melting thin layers of powdered materials applied onto the initial object. Each layer is machined right after it was applied, thus molding the final part step by step.
This laser sculpture can be used to produce parts that are otherwise difficult to craft because of the material they're made of, like ceramics. Normally, ceramic parts can't be crafted without first using a laser to soften the material, said Yung Shin, a professor of mechanical engineering and director of Purdue's Center for Laser-Based Manufacturing, where the new method was developed.
The biggest advantage of the new technique is the fact that it allows complete control over the final shape of the product due to the fact that the laser melts each new layer of deposited material, thus being extremely useful in many industrial applications where complex external and internal details are required.
"For example, if you are making a pump, you may have a lot of internal channels and components made of different materials," Shin said. "Since you can deposit layer by layer, you can create very accurate geometrical shapes, actually building this part from the ground up instead of machining different components and then assembling them into a pump. We can make parts that contain a metal layer followed by a ceramic layer, and so on, which is important for creating components for the electronics industry and for other applications."
The fact that the machining step was added after each layer is melted gives this method its novelty aspect, because the laser deposition technique is not new in itself. However, this is the first one to greatly enhance the precision with which the final product is machined.
"We have improved the method so that it's about 20 times more accurate by adding the ability to machine the part while it is being formed," Shin said. "We have developed a facility that can actually deposit the powder, heat it with the laser and machine it at the same time."
By precisely controlling the temperature and the power of the laser, this technology can quickly create critical components for various military equipment, like jet engine turbine components and gun barrels, but also for the civilian industry, like brake components, artificial knee joints and more efficient data storage devices.