Two-ply ceramic layer with different microstructures

Patent metadata

Field	Value
Publication number	US-2016251971-A1
Application number	US-201415028949-A
Country	US
Kind code	A1
Filing date	May 13, 2014
Priority date	Oct 22, 2013
Publication date	Sep 1, 2016
Grant date	—

Abstract

A two-ply heat-insulating ceramic layer is provided with a highly porous crackfree lower ply and an outermost heat-insulating ply with vertical cracks in order to ensure both a high heat insulation as well as a high erosion resistance. In one aspect is a layer system having a two-ply, outermost ceramic layer, which has a lower ceramic layer and an outermost ceramic layer. The lower ceramic layer has a porosity of at least 5%, in particular at least 8%, very particularly preferably at least 10%, and barely any or no vertical cracks, in particular no vertical cracks running right through, and the outermost ceramic layer has a layer thickness of not more than 40%, in particular not more than 20%, very particularly preferably not more than 10% of the layer thickness of the lower ceramic layer.

First claim

1 . A layer system
having a two-ply, outermost ceramic layer, which has a lower ceramic layer and an outermost ceramic layer, wherein the lower ceramic layer has a porosity of at least 5%, and is substantially free of vertical cracks running therethrough, and the outermost ceramic layer has a layer thickness of not more than 40%, of the layer thickness of the lower ceramic layer.

2 . The layer system as claimed in claim 1 , wherein the outermost ceramic layer has a minimum layer thickness of 30 μm.

3 . The layer system as claimed in claim 1 , wherein the outermost ceramic layer has a maximum layer thickness of 500 μm.

4 . The layer system as claimed in claim 1 , wherein the lower ceramic layer of the two-ply ceramic layer has a porosity of 12+ or −4% and in particular has a layer thickness of up to 1 mm.

5 . The layer system as claimed in claim 1 , wherein the lower ceramic layer of the two-ply ceramic layer has a porosity of 15+ or −4% and in particular has a layer thickness of up to 1 mm.

6 . The layer system as claimed in claim 1 , wherein the lower ceramic layer of the two-ply ceramic layer has a porosity of 20+ or −4% and has a layer thickness of up to 1.5 mm.

7 . The layer system as claimed in claim 1 , wherein the lower ceramic layer of the ceramic layer has a porosity of 25+ or −5% and has a layer thickness of >1.5 mm.

8 . The layer system as claimed in claim 1 , wherein the lower ceramic layer has a porosity of >15%.

9 . The layer system as claimed in claim 1 , wherein the lower ceramic layer of the thermal barrier layer has a ductile columnar structure.

10 . The layer system as claimed in claim 1 , wherein the lower ceramic layer of the two-ply ceramic thermal barrier layer has been produced by an APS process.

11 . The layer system as claimed in claim 1 , wherein the lower ceramic layer of the two-ply ceramic thermal barrier layer has been produced by spraying of ceramic powders with polymers.

12 . The layer system as claimed in claim 1 , wherein the lower ceramic layer of the two-ply, ceramic thermal barrier layer has been produced by suspension plasma spraying.

13 . The layer system as claimed in claim 1 , wherein the materials for the lower ceramic layer and of the outermost ceramic layer are selected from among: zirconium oxide, partially stabilized or fully stabilized, and pyrochlores.

14 . The layer system as claimed in claim 1 , wherein the two-ply ceramic layer is the outermost layer.

15 . The layer system as claimed in claim 1 , wherein the lower ceramic layer has a minimum thickness of at least 100 μm.

16 . The layer system as claimed in claim 1 , wherein the outermost ceramic layer is dense and has a porosity of less than 8%.

17 . The layer system as claimed in claim 1 , wherein the outermost ceramic layer has cracks running vertically through it.

Assignees

• Siemens Ag

Inventors

• Düsterhöft Jens Bay
• Heuser Claus
• Richter Matthias
• Stamm Werner

Classifications

• C23C28/3455

  with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer · CPC title

• F01D5/288 Primary

  Protective coatings for blades · CPC title

• F04D29/542

  Bladed diffusers (fixing blades to stators F01D9/042) · CPC title

• C23C28/3215

  at least one MCrAlX layer · CPC title

• C23C28/042

  including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides · CPC title