Current Designs of Coaxial Nozzles for Laser Cladding

Abstract

Laser Cladding process is one of the most relevant new processes on the industry. Laser Cladding can be applied as rapid manufacturing technique consisting on the direct deposition of metallic alloys layer-by-layer. The resulting parts present a near-net-shape and fully functional properties, which convert this process on a real alternative for the manufacturing of single or very short series of complex geometry parts. On the other hand, Laser Cladding can be applied for coating of previously manufactured parts, in order to obtain optimum surface properties by the addition of a different material. Both applications can be carried out wit the same equipment, which consists basically on a laser source, a kinematic able to transport the laser into a workspace, a material feeder and finally, a headstock that include the optics to focus the laser and the nozzle to inject the added material. The most common industrial solution is to use coaxial powder nozzle to inject the added material into the melt pool. Many of the recent patents and technologies have been focused on the nozzle and powder injection systems in order to increase the powder flow and reduce the diameter of powder stream. This paper presents a study of the main patents focused on Laser Cladding nozzles. The patents have been analyzed and classified into two groups: first, patents developed to describe improvements on nozzles and Laser Cladding systems and, second, patents that purpose new processes, applications or methods for Laser Cladding operations. The analysis shows that, although there are many patented systems and components, there are no closed solutions for industrial Laser Cladding operations. Keywords: Laser cladding, coaxial powder nozzles, rapid manufacturing, Discrete nozzle, Vacuum channel, laser beam, biocompatibility, EDM, welding