Abstract: Apparatus for delivering two or more powders at any controlled ration to a thermal spray apparatus permits the controlled production of graded sprayed coatings. The apparatus also monitors and controls the position of the spray apparatus relative to the workpiece and varies this position during the deposition of the sprayed layers. The apparatus includes in-process mass flow gauges which measure in real time the flow rates of the various powders and report these rates to a supervisory controller which verifies these rates against the predetermined schedule and can shut down the apparatus in the event of a malfunction. The substrate being sprayed has its substrate temperature monitored and controlled according to a predetermined schedule by a supervising controller.

Abstract: Methods of coating metallic substrates with continuously graded metallic-ceramic material are disclosed. The method maintains low stress to strength ratios across the depth of the graded layer when the graded layer is under subsequent operative conditions. In one particular structure, the coating is applied to a metal substrate and includes a metallic bond coat a continuously graded metallic-ceramic layer and an outer layer of abradable ceramic material. Modulation of the metal substrate temperature during the coating process establishes a desired residual stress pattern in the graded layer.

Abstract: Structure coated with graded ceramic material and methods of coating application are disclosed. Techniques for maintaining low stress to strength ratios across the depth of the coating are discussed.In one particular structure the coating is applied to a metal substrate (12) and comprises a metallic bond coat (14), a first interlayer (16) of metal/ceramic material, a second interlayer (18) of metal/ceramic material having an increased proportion of ceramic and an all ceramic layer. Modulation of the metal substrate temperature during the coating process establishes a desired residual stress pattern in the part.

Abstract: Structure coated with graded ceramic material and methods of coating application are disclosed. Techniques for maintaining low stress to strength ratios across the depth of the coating are discussed. In one particular structure the coating is applied to a metal substrate (12) and comprises a metallic bond coat (14), a first interlayer (16) of metal/ceramic material, a second interlayer (18) of metal/ceramic material having an increased proportion of ceramic and an all ceramic layer. Modulation of the metal substrate temperature during the coating process establishes a desired residual stress pattern in the part.