Heat-insulating protective layer for a component located within the hot gas zone of a gas turbine

摘要

Disclosed is a heat-insulating protective layer for a component located within the hot gas zone of a gas turbine. Said protective layer is composed of an adhesive layer, a diffusion layer, and a ceramic layer which is applied to the high temperature-resistant basic metal of the component. The adhesive layer comprises a metal alloy [MCrAlY (M=Ni, Co)] containing Ni, Co, Cr, Al, Y, the diffusion layer is produced by calorizing the adhesive layer, and the ceramic layer is composed of ZrO2 which is partially stabilized by means of yttrium oxide. One or several chemical metal elements that have a large atomic diameter and are selected among the group comprising Re, W, Si, Hf, and/or Ta are alloyed to the material of the adhesive layer. The adhesive layer has the following chemical composition after being applied: Co 15 to 30 percent, Cr 15 to 25 percent, Al 6 to 13 percent, Y 0.2 to 0.7 percent, Re up to 5 percent, W up to 5 percent, Si up to 3 percent, Hf up to 3 percent, Ta up to 5 percent, the remainder being composed of Ni.

主权项

1. A heat-insulating protective layer for a component which is to be located within a hot-gas section of a gas turbine, comprising:
a bonding layer having a Ni, Co, Cr, Al, Y-containing metal alloy, wherein the Ni, Co, Cr, Al, Y-containing metal alloy is MCrAIY, where M=Ni, Co, to which one or more chemical-metal elements with a large atomic diameter selected from the group consisting of Re, W, Si, Hf and Ta are added as alloys such that the bonding layer applied to a high temperature-resistant base metal of the component has a chemical composition in accordance with: Co 15-30 wt. %, Cr 15-25 wt. %, Al 6-13 wt. %, Y 0.2-0.7 wt. %, Re up to 5 wt. %, W up to 5 wt. %, Si up to 3%, Hf up to 3 wt. %, Ta up to 5 wt. %, with a remainder consisting of Ni; a diffusion layer; and a ceramic layer, the diffusion layer arranged between the ceramic layer and the bonding layer; wherein the bonding layer, diffusion layer and ceramic layer are applied to the high temperature-resistant base metal of the component; wherein the diffusion layer is produced by alitization of the bonding layer in that a surface of the bonding layer on the base metal is alitized to form a surface-alitized MCrAlY layer that has a structure consisting of an inner, extensively intact γ, β-mixed phase, the diffusion layer consisting of an inner diffusion zone with an Al content of about 20%, and an outer built-up layer consisting of a β-NiAl phase with an Al content of about 30 wt. %, the outer built-up layer being removed essentially down to the inner diffusion zone of the diffusion layer by an abrasive treatment such that a surface of the diffusion layer has an Al content of more than 18 wt. % and less than 30 wt. %.