Abstract A flame spray powder comprises finely-divided core particles of a metal or a metal alloy coated with discrete particles of a ceramic or cermet that remains in solid phase at least 100*F above the fusing or melting temperature of the metal. The average particle size of the ceramic is less than 25 percent of the average particle size of the metal and the amount used is insufficient to totally cover the surface of the metal particles so that on the average in the range of 5 to 75 percent of the surface area of the metal particles is exposed to ambient conditions. When used in flame spraying, this new ceramic clad metal powderin one embodiment forms a flame spray coating where the ceramic is in the continuous phase and the coating is relatively soft and abradable, and in another embodiment the metal of the coating is in the continuous phase and the coating is relatively hard and erosion resistant.
The powder of claim 1 having a particle size in the range of -100 mesh to 3 microns and wherein in the range of 10 to 50 percent of the surface of said core particles is exposed by said discrete particles which amount to in the range of 1 to 30 volume percent of the volume of the core particles.
Claim 2
Dependent Claim
39 words
The powder of claim 1 wherein said discrete particles are bonded to said core particles with a resinuous binder, said binder amounting to in the range of 0.05 to 5 volume percent of the volume of said core particles.
Claim 3
Dependent Claim
17 words
The powder of claim 1 wherein said metal is a nickel-chromium and said ceramic is boron nitride.
Claim 4
Dependent Claim
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The powder of claim 1 wherein said discrete particles additionally include a material selected from the group comprising metals and ceramics and having an average particle size of less than 25 percent of the size of said metal core particles, the additional material being present in an amount in the range of 0.5 to 15 percent of the volume of the amount of said metal.
Claim 5
Dependent Claim
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The powder of claim 5 wherein said metal is a cobalt-nickel-chromium alloy, said ceramic is a diatomaceous earth and said additional material is aluminum.
Claim 6
Dependent Claim
18 words
The powder of claim 1 wherein said metal and ceramic particles have a globular to generally spherical shape.
Claim 7
Dependent Claim
112 words
A flame sprayed composition obtained by passing a metal-ceramic powder through a flame spray gun and melting at least the metal component thereof; and thereafter impinging the heated powder against a receptor surface, said powder comprising finely-divided core particles of a metal bonded to and coated with discrete particles of a ceramic that remains in solid phase at least 100* F. above the fusing temperature of said metal, said ceramic having an average particle size less than 25 percent of the average particle size of said metal and leaving exposed on the average in the range of 5 to 75 percent of the surface are thereof as determined by the PLMG method.
Claim 8
Dependent Claim
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The composition of claim 8 wherein said ceramic is in the continuous phase and said composition is relatively soft and abradable.
Claim 9
Dependent Claim
26 words
The composition of claim 8 wherein said metal is in the continuous phase and said composition is relatively hard and erosion resistant and not too abradable.