High-temperature environmental thermal barrier coating surface and interface fracture toughness three-point bending detection method

A technology of thermal barrier coating and detection method, which is applied in the direction of testing the strength of materials, measuring devices, and strength characteristics by applying a stable bending force, which can solve the problems of time-consuming, complicated and cumbersome, etc., to improve detection efficiency and save costs , The effect of reducing the loss of materials

Active Publication Date: 2020-02-21
XIANGTAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The purpose of the present invention is to provide a three-point bending detection method for the surface and interface fracture toughness of a thermal barrier coating in a high temperature environment to solve the problem that the dete...

Method used

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  • High-temperature environmental thermal barrier coating surface and interface fracture toughness three-point bending detection method
  • High-temperature environmental thermal barrier coating surface and interface fracture toughness three-point bending detection method
  • High-temperature environmental thermal barrier coating surface and interface fracture toughness three-point bending detection method

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Experimental program
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Effect test

specific Embodiment 1

[0062] Measurement results of surface fracture toughness and interface fracture toughness at room temperature:

[0063] Experimental temperature heating time Testing machine loading rate Ceramic layer thickness crack groove depth room temperature 0min 0.4mm / min 1mm 0.25mm

[0064] According to the pure bending model of three-point bending, the strain at the crack tip can be calculated, and the critical fracture stress can be obtained from the product of the strain and the elastic modulus of the ceramic layer and the residual stress at room temperature, so as to calculate the surface fracture toughness. The formula for calculating surface fracture toughness is:

[0065]

[0066] K 1 : stress intensity factor; ρ: critical stress; a 0 : pre-crack length; Y 1 :Correction factor.

[0067] The appearance of interfacial cracks was observed by DIC, and as the deflection of the sample increased, the interfacial cracks gradually became longer. Ac...

specific Embodiment 2

[0074] Measurement results of surface fracture toughness and interface fracture toughness at 650°C:

[0075] Experimental temperature heating time Testing machine loading rate Ceramic layer thickness crack groove depth 650℃ 17min 0.4mm / min 1.0mm 0.5mm

[0076] According to the pure bending model of three-point bending, the strain at the crack tip can be calculated, and the critical fracture stress can be obtained from the product of the strain and the elastic modulus of the ceramic layer and the residual stress at room temperature, so as to calculate the surface fracture toughness. The formula for calculating surface fracture toughness is:

[0077]

[0078] K 1 : stress intensity factor; ρ: critical stress; a 0 : pre-crack length; Y 1 :Correction factor. The appearance of interfacial cracks was observed by DIC, and as the deflection of the sample increased, the interfacial cracks gradually became longer. According to the data of DIC and ...

specific Embodiment 3

[0085] Measurement results of surface fracture toughness and interface fracture toughness at 1200°C:

[0086] Experimental temperature heating time Testing machine loading rate Ceramic layer thickness crack groove depth 1200℃ 20min 0.4mm / min 1.0mm 0.5mm

[0087] According to the pure bending model of three-point bending, the strain at the crack tip can be calculated, and the critical fracture stress can be obtained from the product of the strain and the elastic modulus of the ceramic layer and the residual stress at room temperature, so as to calculate the surface fracture toughness. The formula for calculating surface fracture toughness is:

[0088]

[0089] K 1 : stress intensity factor; ρ: critical stress; a 0 : pre-crack length; Y 1 :Correction factor.

[0090] The appearance of interfacial cracks was observed by DIC, and as the deflection of the sample increased, the interfacial cracks gradually became longer. According to the data ...

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Abstract

The invention discloses a high-temperature environmental thermal barrier coating surface and interface fracture toughness three-point bending detection method. The method comprises the steps that a thermal barrier coating with a preset thickness is sprayed on a substrate layer according to first preset parameters; a groove with a preset depth is cut in the surface of the thermal barrier coating, and a simulation sample is obtained, wherein the preset depth is smaller than the preset thickness; and the simulation sample is heated for a preset time under a preset temperature, and a to-be-detected sample is obtained; and the surface fracture toughness and interface fracture toughness of the to-be-detected sample are detected. Through the method, one-time DIC (digital image correlation) observation of the thermal barrier coating is realized, the surface fracture toughness and interface fracture toughness of the thermal barrier coating can be detected, and the problems that surface fracturetoughness detection and interface fracture toughness detection of an existing thermal barrier coating need to be performed respectively, and repeated operation of DIC observation is complicated and tedious and consumes a long time are solved. Therefore, the detection efficiency of the surface fracture toughness and interface fracture toughness of the thermal barrier coating is improved, materialloss is reduced, and cost is saved.

Description

technical field [0001] The invention relates to the technical field of material detection, in particular to a three-point bending detection method for the surface and interface fracture toughness of a thermal barrier coating in a high temperature environment. Background technique [0002] Thermal barrier coatings (Thermal Barrier Coatings) are a layer of ceramic coatings, which are deposited on the surface of high-temperature resistant metals or superalloys. Thermal barrier coatings have a thermal insulation effect on the base material and reduce the temperature of the base material, making Advanced devices (such as engine turbine blades) can operate at high temperatures, and can improve the thermal efficiency of devices (engines, etc.) to more than 60%. [0003] At present, research on the application of thermal barrier coatings on turbine blades of aero-engines in my country has begun and has been paid attention to. Thermal barrier coatings have been sprayed on some turbin...

Claims

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Application Information

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IPC IPC(8): G01N3/20
CPCG01N3/20G01N2203/0023G01N2203/0067G01N2203/0064G01N2203/0066G01N2203/0226G01N2203/0218G01N2203/0298G01N2203/0676G01N2203/0682
Inventor 周益春吴乔杨丽朱旺
Owner XIANGTAN UNIV
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