Patent ID: 8651394
Filing Date: 2014-02-18
Classification: B05B,C23C

Abstract:
1. A coating method comprising spraying a jet of gas carrying particulate material by cold gas spraying or by high speed flame spraying through an outlet of a Laval nozzle onto a work piece to form a coating thereon, said Laval nozzle comprising a converging section and a diverging section, at a gas temperature of not more than 800° C. and below the melting temperature of the particulate material and through a Laval nozzle that is devoid of abrupt transitions, which would disrupt the uniformity of the gas flow, and wherein the divergent section has a sufficient extent of continuously curving concave walls to provide an increase in the percentage of particles that affix to the work piece compared to the use of a cone-shaped divergent section, and so as to provide a jet at the outlet having a velocity of a Mach number between 2.5 and 5.