Laser Deposit Welding with Powder
High Quality Coating with Metallic Powders
Wear protection and repair layers can be generated by laser deposition from metallic powder locally and by minimizing the heat load to the work piece. The powder is fed into the melting zone on the surface of the work piece by using a carrier gas. This results in a non-porous layer with little distortion. Even with moderate power densities layers with a thickness of 0.5 to 1 mm and a width of up to a few millimeters can be deposited at a speed of several 100 mm/min. Thicker layers and wider paths can be generated by scanning several layers one upon the other and in parallel ways.
Due to the better absorption of the laser beam on metal surfaces and in powder particles at shorter wavelengths, lasers with a wavelength range of 1 µm (mostly solid state lasers) are usually more efficient and more cost-effective for powder cladding than CO2 lasers. Especially high power diode lasers are ideal for these requirements, as they are providing an optimal wavelength (800 – 1000 µm) and a high efficiency but a small size.