Patent ID: 6322856
Filing Date: 2001-11-27
Classification: B05B,C23C,H05H

Abstract:
A method of plasma coating objects including:evacuating a chamber in which a plasmatron including a cathode, an anode, and an axial bore in the anode is disposed to a predetermined vacuum;charging the chamber with a non-reactive gas to an operating pressure;placing an object in the chamber and in the plasmatron discharge path;providing a source of powder to the plasmatron;providing a plasma powder injection conduit having a predetermined length and terminating at and in communication with said axial bore and having an essentially straight uninterrupted section having a length of at least 4.8 times its internal diameter terminating at said axial bore;creating a plasma stream in the plasmatron;feeding powder from the powder source to the plasma stream through the plasma powder injection conduit;heating the powder to high temperature by the plasma stream;transporting the powder at high velocity by the plasma stream to the object; andimpinging the powder on the object to create a coating.