Development of a low cost system for the cold spray process with helium

摘要

The use of helium with the cold spray process is well-known to give a higher velocity to the particles and thus denser coatings than those obtained with the classical use of nitrogen. The LERMPS-UTBM laboratory has developed a unique system to use helium without losses. The spray process occurs in a LPPS tank and a specific closed circuit including the cooling and filtering of helium allows its circulation. The spray operations can be made at low helium pressure with no pollution by oxygen. The control device allows to work with different pressures and gas temperatures at the torch with the same tank pressure. Helium gas flow can reach 180 Nm{sup}3/h and current cold spray torches could be used. The circulation and reuse of helium in a closed circuit result in a very low consumption of helium. The first coatings of copper alloys are presented in this work.