Gas dynamic cold spray

Cold spraying is a coating process in which the coating material is applied in powder form at a very high speed to the carrier material (substrate). To a heated to a few hundred degrees of process gas is accelerated by expansion in a Laval nozzle to a supersonic speed, and then injects the powder particles in the gas jet. The injected spray particles are accelerated to such a high speed that they form, in contrast to other thermal spray processes without advance continuous presence or melting on impact with the substrate a dense and adherent layer. The kinetic energy at the time of impact is not sufficient for a complete melting of the particles.

Cold spraying was developed in the mid -80s at the Institute of Theoretical and Applied Mechanics of the Siberian Branch of the Russian Academy of Sciences in Novosibirsk and is also pursuing further there today. One of the scientists working there, Anatoly Papyrin, began in 1994 with a consortium of U.S. companies, including Alcoa, ASB Industries, Ford, K-Tech, Pratt & Whitney and Siemens Westinghouse, and the Sandia National Lab, working on the further industrialization of the process. In Germany, the development was, inter alia, driven by the company Linde cooperation with the University of the Federal Armed Forces Hamburg. For the construction and marketing of cold gas injection equipment, the company CGT Cold Gas Technology GmbH established. According to information the company has transferred Papyrin 2006, his basic patent on this.

Cold spraying is used industrially today in the automobile industry to gradually rise to new fields such as in the area of ​​tool repair and tool (Rapid Manufacturing) and in the field of microtechnology.