PLASMA FLAME-SPRAYING PROCESS EMPLOYING SUPERSONIC GASEOUS STREAMS

摘要

This invention describes an improved process for plasma flame-spraying of powder particles of metal, metal oxide, carbide, ceramic or the like whereby improved coatings are provided together with longer nozzle and gun life. Particularly described is an improved process for plasma flame-spraying wherein higher velocities of gas together with smaller gas passages are employed, and other parameters are selected so as to establish the arc created during the plasma flame-spraying process at the exit rim of the nozzle whereby substantially higher power can be tolerated. This is turn provides n markedly increased deposit efficiency in respect of the coating and allows powder feed rates into the resultant flame generally higher than heretofore employed.