The Perkin-Elmer Corporation

John E Nerz

Anthony J Rotolico

Burton A Kushner

Martin E Hacker

Anthony J Fuimefreddo

Lawerence A Saia

Gunther Hain

A rotor blade is for a gas turbine engine having a plurality of rotor blades and a substantially coaxial shroud encompassing the tips of the blades. A ceramic layer is bonded to the blade tip, the ceramic layer consisting of a combination of aluminum oxide and zirconium oxide or at least partially stabilized zirconium oxide. The ceramic layer is formed as a plasma sprayed coating or a high velocity oxy-fuel sprayed coating.

Turbine rotor blade tip coated with alumina-zirconia ceramic

The front face of the nozzle of a plasma spray device has a shallow annular recession therein. The recession is bounded inwardly by an extended portion of the nozzle, outwardly by a ring member and rearwardly by an inner surface. The ring member has therein a plurality of arcuately equally spaced holes directed radially inward toward the inner face, the holes communicating with a source of air. Powder is injected radially into the plasma stream external to the nozzle member proximate the outlet end. The air flow from the holes and entrainment of surrounding atmosphere by the plasma stream drive a toroidal vortex anchored in the recession, the vortex effecting a wiping flow on the nozzle face such as to inhibit powder from depositing on the nozzle face.

Plasma spray device with external powder feed

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Seldon, NY, United States of America

John E Nerz