Abstract: A feedstock injector for connection to a source of heated gas comprises a converging channel extending from the upstream end to the downstream end of the injector. A splitting arm extends diagonally within the converging channel, the splitting arm comprising two symmetrically opposed surfaces extending from the inlet to the outlet ends of the converging channel. A feedstock injection passage opens axially at the downstream end of the splitting arm. The gas stream discharged by the injector contacts and entrains the feedstock with improved uniformity.

Abstract: A plasmatron operating efficiently within a wider range of gas flows and capable of sustaining a stable arc voltage. The plasmatron generates an electric arc at the tip of a cathode electrode and transfers the arc along an arc chamber and into the bore of an anode electrode located at the downstream end of the arc chamber. A plurality of arc root attachment surfaces are defined on an inner surface of the anode by a plurality of ring members, causing the electric arc to attach with its root to the arc root attachment surfaces and therefore the axial movement of the arc root is confined substantially to the anode electrode. The arc voltage variations are limited and controlled substantially by the arc root movement between two adjacent arc root attachment surfaces. When used within a plasma-spraying torch, the plasma stream generated by the plasmatron has improved characteristics and induces improved plasma spray coatings.