High-velocity arc spraying - The renaissanceof a coating process

The industrial growth in the past decades and the ever more stringent profile of requirements on technical products with regard to the concept of sustainability are necessitating the selective adaptation and refinement of existing installation technology towards the conservation of energy and resources. The process variants of thermal spraying are represented as a key technology in nearly all fields of industrial undertakings. The latest growth figures reflect the enormous potential of this high-end technology. Until now, arc wire spraying has played a rather subordinate role in the thermal spraying group. The reason for this living in the shadows is that individual branches of research and industry are fixed on highly kinetic plasma, flame and cold gas processes. The set target described above is focusing on so-called low-cost processes such as arc wire spraying and is thus ensuring a renaissance of this coating method. The development of a new process variant of arc spraying is presented in this article. The pursued concept is based on the so-called open atomisation of the spraying consumable and includes gas flows at supersonic velocities as well as their needs. The high-velocity system was calculated numerically and, in a widely based series of experiments, was tested practically in direct comparison with the closed standard system.