A nano/columnar-like mixed structure thermal barrier coating and its preparation method

Abstract

The invention relates to a nanometer / columnar-like crystal mixing structure thermal barrier coating and a preparation method thereof. The mixing structure thermal barrier coating is a nanometer / columnar-like crystal mixing structure coating, and comprises a substrate, a metal bonding layer and a ceramic layer, wherein the metal bonding layer and the ceramic layer are sequentially coated on the substrate, the ceramic layer comprises unmelted nanoparticles, nanometer pores, nanometer crystal and ultrafine crystal, and has cracks perpendicular to the substrate, and the cracks form the columnar-like crystal structure. The mixing structure thermal barrier coating preparation method comprises powder selection, a pretreatment step, a substrate pretreatment step, a metal bonding layer preparation step, and a 6-8% YSZ ceramic layer preparation step. The coating disclosed by the present invention has characteristics of high strain tolerance, excellent thermal insulation performance, high bonding strength, high thermal cycle life, and high thermal shock life, such that the thermal barrier coating has a good comprehensive performance.

Description

technical field

[0001] The present invention relates to a method for preparing a novel hybrid structure thermal barrier coating, in particular to a method of spraying nanometer YSZ powder using a conventional plasma spraying process to prepare a nano / columnar crystal mixed structure thermal barrier coating with higher strain tolerance and good comprehensive performance. barrier coating method. Background technique

[0002] Thermal Barrier Coating (TBC) is a high-temperature structural material surface protection technology that uses the excellent high-temperature resistance, heat insulation, and corrosion resistance of ceramic materials to combine ceramics and metal substrates in the form of coatings. It is composed of a ceramic surface layer with high conductivity and a metal bonding layer with good thermal expansion coefficient matching with the metal substrate and ceramic surface layer. The use of thermal barrier coatings will significantly increase the operating tempera...

Examples

preparation example Construction

[0062] see figure 2 , figure 2 It is a flow chart of the method of the present invention. The preparation method of the hybrid structure thermal barrier coating of the present invention comprises the following steps:

[0063] Powder selection and pretreatment step a, select nano-agglomerated YSZ spray powder and perform high-temperature sintering or plasma densification treatment; preferably, the nano-agglomerated YSZ spray powder contains 6-8 wt% Y 2 o 3 Partially stabilized ZrO 2 , and the fluidity of the nano-agglomerated YSZ spray powder is less than 60s / 50g, and the bulk density is greater than 1.6g / cm 3 .

[0064] In the substrate pretreatment step b, the substrate 1 is provided and the substrate 1 is cleaned and sandblasted; the substrate 1 is preferably a high-temperature alloy or heat-resistant steel.

[0065] Prepare the metal bonding layer step c, the metal alloy powder is prepared by plasma spraying or supersonic flame spraying to prepare the metal bonding ...

Embodiment 1

[0085] Example 1: Preparation of coating on the surface of DZ40M superalloy substrate 1

[0086] Step a: Powder selection and preparation

[0087] Select nanometer YSZ agglomerated powder, after powder agglomeration, undergo plasma densification treatment, the particle size range of the sprayed powder is -90μm~+37μm, and the bulk density is 1.74g / cm 3 , the fluidity is 52s / 50g, the powder is used for plasma spraying after drying at 100°C for 2 hours.

[0088] Step b: Substrate 1 pretreatment

[0089] Choose a cobalt-based superalloy, the grade is DZ40M, soak the superalloy substrate 1 in acetone, take it out and dry it after 1 hour; Compressed air blows off residual sand particles on the surface.

[0090] Step c: Preparation of metal bonding layer 2 by supersonic flame spraying

[0091] The preparation of the bonding layer is mainly NiCrAlY metal alloy powder, the particle size range of the powder is -45μm ~ +15μm, according to the preparation process parameters of the met...

Embodiment 2

[0095] Embodiment 2: prepare coating on MGH754Ni-Cr alloy substrate surface

[0096] Step a: Powder selection and preparation

[0097] Select nanometer YSZ agglomerated powder, after powder agglomeration, undergo plasma densification treatment, the particle size range of the sprayed powder is -61μm~+38μm, and the bulk density is 1.85g / cm 3 , the fluidity is 47s / 50g, the powder is used for plasma spraying after drying at 100°C for 2 hours.

[0098] Step b: Substrate 1 pretreatment

[0099] Select the dispersion strengthened NiCr heat-resistant alloy, the grade is MGH754, soak the superalloy substrate 1 in acetone, take it out and dry it after 1 hour; 1 Use compressed air to blow off the residual sand particles on the surface.

[0100] Step c: Preparation of metal bonding layer 2 by plasma spraying

[0101] For the preparation of the bonding layer, the metal alloy powder whose main component is NiCoCrAlY is selected, and the particle size range of the powder is -75μm~+45μm. ...

technical field

[0001] The present invention relates to a method for preparing a novel hybrid structure thermal barrier coating, in particular to a method of spraying nanometer YSZ powder using a conventional plasma spraying process to prepare a nano / columnar crystal mixed structure thermal barrier coating with higher strain tolerance and good comprehensive performance. barrier coating method. Background technique

[0002] Thermal Barrier Coating (TBC) is a high-temperature structural material surface protection technology that uses the excellent high-temperature resistance, heat insulation, and corrosion resistance of ceramic materials to combine ceramics and metal substrates in the form of coatings. It is composed of a ceramic surface layer with high conductivity and a metal bonding layer with good thermal expansion coefficient matching with the metal substrate and ceramic surface layer. The use of thermal barrier coatings will significantly increase the operating tempera...

Examples

preparation example Construction

[0062] see figure 2 , figure 2 It is a flow chart of the method of the present invention. The preparation method of the hybrid structure thermal barrier coating of the present invention comprises the following steps:

[0063] Powder selection and pretreatment step a, select nano-agglomerated YSZ spray powder and perform high-temperature sintering or plasma densification treatment; preferably, the nano-agglomerated YSZ spray powder contains 6-8 wt% Y 2 o 3 Partially stabilized ZrO 2 , and the fluidity of the nano-agglomerated YSZ spray powder is less than 60s / 50g, and the bulk density is greater than 1.6g / cm 3 .

[0064] In the substrate pretreatment step b, the substrate 1 is provided and the substrate 1 is cleaned and sandblasted; the substrate 1 is preferably a high-temperature alloy or heat-resistant steel.

[0065] Prepare the metal bonding layer step c, the metal alloy powder is prepared by plasma spraying or supersonic flame spraying to prepare the metal bonding ...

Embodiment 1

[0085] Example 1: Preparation of coating on the surface of DZ40M superalloy substrate 1

[0086] Step a: Powder selection and preparation

[0087] Select nanometer YSZ agglomerated powder, after powder agglomeration, undergo plasma densification treatment, the particle size range of the sprayed powder is -90μm~+37μm, and the bulk density is 1.74g / cm 3 , the fluidity is 52s / 50g, the powder is used for plasma spraying after drying at 100°C for 2 hours.

[0088] Step b: Substrate 1 pretreatment

[0089] Choose a cobalt-based superalloy, the grade is DZ40M, soak the superalloy substrate 1 in acetone, take it out and dry it after 1 hour; Compressed air blows off residual sand particles on the surface.

[0090] Step c: Preparation of metal bonding layer 2 by supersonic flame spraying

[0091] The preparation of the bonding layer is mainly NiCrAlY metal alloy powder, the particle size range of the powder is -45μm ~ +15μm, according to the preparation process parameters of the met...

Embodiment 2

[0095] Embodiment 2: prepare coating on MGH754Ni-Cr alloy substrate surface

[0096] Step a: Powder selection and preparation

[0097] Select nanometer YSZ agglomerated powder, after powder agglomeration, undergo plasma densification treatment, the particle size range of the sprayed powder is -61μm~+38μm, and the bulk density is 1.85g / cm 3 , the fluidity is 47s / 50g, the powder is used for plasma spraying after drying at 100°C for 2 hours.

[0098] Step b: Substrate 1 pretreatment

[0099] Select the dispersion strengthened NiCr heat-resistant alloy, the grade is MGH754, soak the superalloy substrate 1 in acetone, take it out and dry it after 1 hour; 1 Use compressed air to blow off the residual sand particles on the surface.

[0100] Step c: Preparation of metal bonding layer 2 by plasma spraying

[0101] For the preparation of the bonding layer, the metal alloy powder whose main component is NiCoCrAlY is selected, and the particle size range of the powder is -75μm~+45μm. ...

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