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CN-122011933-A - High-temperature gradient change resistant thermal barrier coating and preparation method thereof

CN122011933ACN 122011933 ACN122011933 ACN 122011933ACN-122011933-A

Abstract

The invention discloses a high-temperature gradient change resistant thermal barrier coating and a preparation method thereof, and relates to the technical field of high-performance coatings. The invention has the advantages that the heat-resistant filler and the composite bonding system are reasonably arranged in each layer by arranging the multi-layer structure, so that the coating forms the thermal expansion characteristic and the structural gradient of gradual transition from the substrate to the surface, the thermal stress generated in the alternating process of cold and hot can be effectively dispersed, the interface cracking and peeling risks are reduced, meanwhile, the low heat conduction structure constructed in the heat insulation layer can obviously slow down the heat transfer to the substrate direction, and the surface sealing layer improves the oxidation resistance and the medium permeation resistance of the coating, thereby ensuring that the coating can still keep stable adhesion and good heat insulation effect under the conditions of high temperature and rapid temperature change, and the heat insulation structure is suitable for long-term use of an automobile exhaust system and other high-temperature components.

Inventors

  • HAN ZHENYUE
  • LIU LINGFENG

Assignees

  • 广东安捷伦新材料科技有限公司
  • 河南安捷伦新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260331

Claims (10)

  1. 1. The high-temperature gradient change resistant thermal barrier coating is characterized by sequentially comprising a base layer bonding layer, a buffer transition layer, a heat insulation layer and a surface sealing layer from bottom to top; Wherein, the The base layer bonding layer comprises the following components in parts by mass: 20-35 parts of silicone resin, 25-45 parts of aluminum powder, 10-25 parts of nickel powder, 8-20 parts of aluminum oxide powder, 5-12 parts of talcum powder, 10-22 parts of silica sol, 0.5-2 parts of dispersing agent, 0.2-1 part of defoaming agent, 0.2-1 part of leveling agent and 15-40 parts of solvent; The buffer transition layer comprises the following components in parts by mass: 18-30 parts of silicone resin, 20-35 parts of alumina powder, 15-30 parts of zirconia powder, 10-25 parts of mullite powder, 5-15 parts of mica powder, 8-20 parts of silica sol, 3-10 parts of glass powder, 0.5-2 parts of dispersing agent, 0.2-1 part of defoaming agent, 0.2-1 part of leveling agent and 10-35 parts of solvent; the heat insulation layer comprises the following components in parts by weight: 35-60 parts of zirconia powder, 10-25 parts of alumina powder, 15-35 parts of hollow ceramic microbeads, 5-15 parts of diatomite powder, 8-18 parts of mullite powder, 10-25 parts of silica sol, 8-18 parts of silicone resin, 2-8 parts of glass powder, 0.5-2 parts of dispersing agent, 0.2-1 part of defoaming agent, 0.2-1 part of leveling agent and 10-30 parts of solvent; The surface sealing layer comprises the following components in parts by mass: 20-35 parts of silicone resin, 15-30 parts of silica sol, 10-20 parts of alumina powder, 8-18 parts of zirconia powder, 5-12 parts of mica powder, 5-15 parts of glass powder, 2-8 parts of titanium dioxide, 0.3-1.5 parts of dispersing agent, 0.2-1 part of defoaming agent, 0.2-1 part of leveling agent and 15-35 parts of solvent.
  2. 2. The high temperature gradient resistant thermal barrier coating according to claim 1, wherein the base bond coat is prepared by a process comprising: firstly, adding silicon resin, a solvent, a dispersing agent and a defoaming agent into a stirring container, and premixing for 5-15 min at a rotating speed of 300-800 r/min to form an initial liquid phase system; then slowly adding alumina powder and talcum powder, and increasing the stirring rotation speed to 800-1500 r/min, and dispersing for 20-40 min; Adding aluminum powder and nickel powder, and continuously stirring for 10-30 min to uniformly distribute the metal powder and the ceramic powder in a resin system; And after the slurry is uniformly dispersed, adding silica sol and a leveling agent, and adding a solvent to adjust the construction viscosity to finally obtain the base layer bonding layer coating.
  3. 3. The high temperature gradient change resistant thermal barrier coating of claim 1, wherein the buffer transition layer is prepared by a process comprising: firstly, adding silicon resin, silica sol, a solvent and a dispersing agent into a dispersing kettle, and stirring for 10-20 min at 500-1000 r/min to form a composite bonding phase; Then sequentially adding alumina powder, zirconia powder and mullite powder for high-speed dispersion of 800-1500 r/min, wherein the dispersion time is preferably 20-50 min; After the mica powder and the glass powder are uniformly dispersed, adding the mica powder and the glass powder, and continuously mixing for 10-20 min at a rotating speed of 500-1000 r/min; and finally adding a defoaming agent, a leveling agent and a solvent, and adjusting to viscosity suitable for construction to prepare the buffer transition layer coating.
  4. 4. The high temperature gradient resistant thermal barrier coating according to claim 1, wherein the preparation process of the thermal insulation layer comprises: Firstly, adding silica sol, silicone resin, a solvent and a dispersing agent into a mixing container, and stirring to form a liquid phase bonding matrix; sequentially adding zirconia powder, alumina powder, mullite powder and diatomite powder, and dispersing for 20-40 min under the condition of 800-160 r/min to form uniform heat insulation framework slurry; Then the rotating speed is reduced to 300-600 r/min, hollow ceramic microbeads and glass powder are slowly added, and the mixing is continued for 5-15 min, so that the hollow ceramic microbeads are uniformly dispersed without obvious breakage; And finally adding a defoaming agent, a leveling agent and a solvent, adjusting the viscosity, and filtering to obtain the heat-insulating layer coating.
  5. 5. The high temperature gradient resistant thermal barrier coating according to claim 1, wherein the surface closing layer is prepared by a process comprising: Firstly, mixing silicone resin, silica sol, a solvent and a dispersing agent to form a basic liquid phase, then sequentially adding alumina powder, zirconia powder, titanium pigment and glass powder, and dispersing at a medium-high speed of 500-1000 r/min for 20-40 min; Adding mica powder, and continuously stirring for 5-15 min at a lower rotating speed of 300-500 r/min so as to keep the morphology of the flaky particles; and finally adding a defoaming agent and a leveling agent, adjusting the viscosity, and filtering to obtain the surface sealing layer coating.
  6. 6. The high-temperature gradient change resistant thermal barrier coating according to claim 1, wherein the composite bonding system is formed by silicon resin and silica sol, wherein the silicon resin is high-temperature resistant organic silicon resin, the temperature resistant grade is not lower than 500 ℃, the solid content is 40% -70%, the silica sol is an aqueous or alcoholic silica dispersion system with the particle size of 10-50 nm and the solid content of 20% -40%, and the mass ratio of the silicon resin to the silica sol is 0.5:1-2:1.
  7. 7. The high temperature gradient resistant thermal barrier coating according to claim 1, wherein the glass powder used in the coating is low softening temperature inorganic glass particles, the softening temperature is 450-750 ℃, the average particle size of the particles is 1-30 μm, the thermal expansion coefficient is 4 x 10 -6 ～9×10 -6 /°, and the glass powder comprises borosilicate glass or aluminosilicate glass system.
  8. 8. The high-temperature gradient change resistant thermal barrier coating according to claim 1, wherein the hollow ceramic microbeads in the thermal insulation layer are ceramic particles with a closed hollow structure, the outer shell of the ceramic particles is composed of alumina or alumina-silicon composite ceramic, the average particle size is 10-80 μm, the shell thickness is 1-8 μm, the apparent density is 0.2-0.8 g/cm < 3 >, and the volume of the hollow cavities accounts for 60% -90% of the total volume of the particles.
  9. 9. The high-temperature gradient change resistant thermal barrier coating according to claim 1, wherein the zirconia powder used in the thermal insulation layer is stabilized zirconia particles, the stabilizer is yttria or magnesia, the mass percentage of the stabilizer is 3% -10%, the average particle size of the particles is 0.5-10 μm, the specific surface area is 1-10 m2/g, and a tetragonal phase or a cubic phase is taken as a main crystal form.
  10. 10. A method for preparing a thermal barrier coating resistant to high temperature gradient changes, based on the thermal barrier coating of any one of claims 1-9, comprising the steps of: s1, preprocessing a substrate to be coated; S2, coating and curing a base layer bonding layer on the surface of the substrate; S3, coating and curing a buffer transition layer on the surface of the base layer bonding layer; S4, coating and curing the heat insulation layer on the surface of the buffer transition layer; S5, coating the surface of the heat insulation layer and forming a surface sealing layer; s6, carrying out staged heat treatment and performance stabilization treatment on the integral thermal barrier coating.

Description

High-temperature gradient change resistant thermal barrier coating and preparation method thereof Technical Field The invention relates to the technical field of high-performance coatings, in particular to a high-temperature gradient change resistant thermal barrier coating and a preparation method thereof. Background With the development of automobile engines to high power density and high thermal efficiency, the parts of an exhaust manifold, a turbocharger shell, a front section of an exhaust pipe, a high-temperature protection part and the like are in a severe temperature fluctuation environment for a long time in the working process, and particularly under the working conditions of cold start, rapid acceleration, high-load operation, flameout cooling and the like, the surface temperature of a part can be greatly changed in a short time, so that a remarkable temperature gradient is formed. To reduce damage to the metal substrate from high temperatures and to reduce heat transfer to surrounding structures, heat resistant or insulating coatings are typically applied to the surfaces of the components. However, the thermal barrier coating in the prior art mostly adopts a single-layer or simple multi-layer structure, the thermal expansion coefficient of the thermal barrier coating is larger than that of a metal matrix, larger thermal stress is easy to generate in the repeated cold and hot circulation process, the coating is cracked, peeled or pulverized, and the service life of the thermal barrier coating is limited. Therefore, there is a need to provide a thermal barrier coating which can maintain stable structure under the condition of rapid temperature change, has high heat insulation capability and is not easy to crack and fall off, and a preparation method thereof, so as to meet the requirement of long-term reliable operation of high-temperature components of automobiles. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a high-temperature gradient change resistant thermal barrier coating and a preparation method thereof, so as to solve the problems in the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a high-temperature gradient change resistant thermal barrier coating, which sequentially comprises a base layer bonding layer, a buffer transition layer, a heat insulation layer and a surface sealing layer from bottom to top; Wherein, the The base layer bonding layer comprises the following components in parts by mass: 20-35 parts of silicone resin, 25-45 parts of aluminum powder, 10-25 parts of nickel powder, 8-20 parts of aluminum oxide powder, 5-12 parts of talcum powder, 10-22 parts of silica sol, 0.5-2 parts of dispersing agent, 0.2-1 part of defoaming agent, 0.2-1 part of leveling agent and 15-40 parts of solvent; The buffer transition layer comprises the following components in parts by mass: 18-30 parts of silicone resin, 20-35 parts of alumina powder, 15-30 parts of zirconia powder, 10-25 parts of mullite powder, 5-15 parts of mica powder, 8-20 parts of silica sol, 3-10 parts of glass powder, 0.5-2 parts of dispersing agent, 0.2-1 part of defoaming agent, 0.2-1 part of leveling agent and 10-35 parts of solvent; the heat insulation layer comprises the following components in parts by weight: 35-60 parts of zirconia powder, 10-25 parts of alumina powder, 15-35 parts of hollow ceramic microbeads, 5-15 parts of diatomite powder, 8-18 parts of mullite powder, 10-25 parts of silica sol, 8-18 parts of silicone resin, 2-8 parts of glass powder, 0.5-2 parts of dispersing agent, 0.2-1 part of defoaming agent, 0.2-1 part of leveling agent and 10-30 parts of solvent; The surface sealing layer comprises the following components in parts by mass: 20-35 parts of silicone resin, 15-30 parts of silica sol, 10-20 parts of alumina powder, 8-18 parts of zirconia powder, 5-12 parts of mica powder, 5-15 parts of glass powder, 2-8 parts of titanium dioxide, 0.3-1.5 parts of dispersing agent, 0.2-1 part of defoaming agent, 0.2-1 part of leveling agent and 15-35 parts of solvent. Further optimizing the technical scheme, the preparation process of the base layer bonding layer comprises the following steps: firstly, adding silicon resin, a solvent, a dispersing agent and a defoaming agent into a stirring container, and premixing for 5-15 min at a rotating speed of 300-800 r/min to form an initial liquid phase system; then slowly adding alumina powder and talcum powder, and increasing the stirring rotation speed to 800-1500 r/min, and dispersing for 20-40 min; Adding aluminum powder and nickel powder, and continuously stirring for 10-30 min to uniformly distribute the metal powder and the ceramic powder in a resin system; And after the slurry is uniformly dispersed, adding silica sol and a leveling agent, and adding a solvent to adjust the construction viscosity to finally obtain the base layer bon