CN112275593A - Method for improving coating microstructure - Google Patents
Method for improving coating microstructure Download PDFInfo
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- CN112275593A CN112275593A CN202011106777.8A CN202011106777A CN112275593A CN 112275593 A CN112275593 A CN 112275593A CN 202011106777 A CN202011106777 A CN 202011106777A CN 112275593 A CN112275593 A CN 112275593A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D1/00—Processes for applying liquids or other fluent materials
- B05D1/02—Processes for applying liquids or other fluent materials performed by spraying
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D1/00—Processes for applying liquids or other fluent materials
- B05D1/36—Successively applying liquids or other fluent materials, e.g. without intermediate treatment
- B05D1/38—Successively applying liquids or other fluent materials, e.g. without intermediate treatment with intermediate treatment
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
- B05D3/02—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
- B05D3/12—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by mechanical means
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Coating By Spraying Or Casting (AREA)
Abstract
A method for improving the microstructure of a coating comprises the steps of heating the back of a base material to a certain temperature (the heating temperature of the back of a ceramic powder base material sprayed is 600-700 ℃, and the heating temperature of the back of a metal powder base material sprayed is 350-450 ℃) before spraying. During the spraying process, the back surface of the base material is kept heated, and meanwhile, the surface of the deposited coating is strengthened (shot peening can be adopted for spraying ceramic powder, and laser shock peening can be adopted for spraying metal powder). And repeating the steps until the coating reaches a certain thickness, and stopping spraying. The microstructure of the coating is improved by heating the back surface of the base material to a constant temperature and performing impact reinforcement on the surface of the deposited coating in the spraying process. Compared with the coating microstructure prepared by the traditional method, the improved coating microstructure is compact, the porosity is reduced, the layered structure is partially disappeared, and the coating performance is greatly improved.
Description
Technical Field
The invention belongs to the technical field of coating preparation, and particularly relates to a method for improving a coating microstructure.
Background
In recent years, with the optimization of power structures, the development of operation technologies such as deep peak regulation, quality improvement and efficiency improvement, the construction of advanced power generation technologies and large power stations, power equipment faces new and worse working conditions. The equipment such as thermal power generation, nuclear power steam turbines, pumps and the like through-flow components, water head turbine through-flow components, power station fluid pipelines and the like are increasingly damaged at a high speed and a high degree under the coupling action of various severe working conditions such as water erosion, cavitation erosion, abrasion and the like in the service process. The requirement of the parts on the service life of the coating is higher and higher, and the traditional thermal spraying coating applied to conventional thermal power and hydroelectric equipment for many years is difficult to meet the requirement that the power development cannot be met.
The traditional thermal spraying coating is essentially a layered structure sediment formed by stacking melted metal or ceramic flat particles, a large number of unbonded interfaces exist among layers (the interface of conventional plasma spraying ceramic is not bonded by up to 70 percent), meanwhile, a large number of unbonded interfaces exist in the preparation process of the metal coating, and pores penetrating to a base material can be formed in the coating by mutual penetration of the unbonded interfaces, so that a corrosive medium in a service environment can easily reach the base material along the through pores, and effective physical shielding can not be provided for the base material; under the mechanical action of water erosion, cavitation erosion, abrasion and the like, the coating is peeled off one by taking single flat particles as units, so that the coating is quickly thinned. On the other hand, because the thermal spray coating and the base material are mechanically combined, the bonding strength is relatively low and is usually not higher than 70MPa, and the coating may be peeled off locally or wholly by the high-stress mechanical action of repeated vibration, water erosion, cavitation and the like of the component, so that the coating fails rapidly, and the intrinsic excellent characteristics of the coating material are difficult to exert. The main strategy for improving the service performance and service life of the thermal spraying coating and further meeting the development requirements of the power industry is to improve the bonding proportion among flat particles in the thermal spraying coating and the bonding strength between the coating and a base material.
Disclosure of Invention
In order to solve the above problems, the present invention provides a method for improving the microstructure of a coating, which can effectively improve the interlayer bonding of flat particles in the coating, thereby improving the coating performance.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method of modifying the microstructure of a coating comprising the steps of:
step 1: before the coating is prepared, degreasing the surface of the base material, and then sandblasting the surface to the required roughness;
step 2: after the sand blasting is finished, the back surface of the base material is heated before spraying, and then spraying is started; in the spraying process, the back surface of the base material is kept heated all the time;
and step 3: strengthening the surface of the deposited coating in the spraying process;
and 4, step 4: repeating the step 2 and the step 3 until the coating reaches the preset thickness, and stopping spraying;
and 5: and after the spraying is stopped, the heating of the back surface of the base material is slowly stopped, and the temperature is kept to be gradually reduced in the stopping process.
The heating mode of the back surface of the base material can be selected from oxyacetylene flame heating, electromagnetic induction heating and the like;
the back heating temperature of the base material is determined according to the type of the powder to be sprayed, the back heating temperature of the ceramic powder base material is 600-700 ℃, and the back heating temperature of the metal powder base material is 350-450 ℃.
The strengthening treatment is determined according to the type of the powder to be sprayed, the ceramic powder can be sprayed by adopting a shot blasting process for strengthening, and the metal powder can be sprayed by adopting laser shock strengthening.
The shot blasting process uses ceramic shots with a chemical composition of approximately 67% ZrO231% of SiO2And 2% of Al2O3The main impurities are prepared by melting, atomizing, drying, selecting round and screening, and the hardness is equal to HRC 57-63; the working pressure of the ceramic pill is 0.4-0.6 MPa.
The laser power density of the laser shock peening is 0.4GW/cm2～1.2GW/cm2The pulse frequency is adjustable between 0Hz and 10 Hz.
The invention has the following advantages:
1) the invention achieves the purpose of improving the microstructure of the coating by heating the back surface of the base material to a constant temperature and carrying out impact reinforcement on the surface of the deposited coating in the spraying process, and has simple method and strong operability.
2) Compared with the coating microstructure prepared by the traditional method, the improved coating microstructure is compact, the porosity is reduced, the layered structure is partially disappeared, and the coating performance is greatly improved.
Drawings
Fig. 1 is a schematic view of a typical thermal spray coating microstructure.
FIG. 2 is a schematic view of the microstructure of a thermal spray coating prepared by the method of the present invention.
Detailed Description
The invention is described in further detail below with reference to the figures and specific examples.
The invention relates to a method for improving the microstructure of a coating, which comprises the following steps:
step 1: before the coating is prepared, degreasing the surface of the base material, and then sandblasting the surface to the required roughness;
step 2: after the sand blasting is finished, heating the back surface of the base material to a certain temperature before spraying, and then starting spraying; in the spraying process, the back surface of the base material is kept heated all the time;
and step 3: synchronously carrying out strengthening treatment on the surface of the deposited coating in the spraying process;
and 4, step 4: repeating the step 2 and the step 3 until the coating reaches a certain thickness, and stopping spraying;
and 5: and after the spraying is stopped, the heating of the back surface of the base material is slowly stopped, and the temperature is kept to be gradually reduced in the stopping process.
The improved coating microstructure is shown in fig. 2, in contrast to a typical thermal spray coating microstructure (shown in fig. 1), where it can be seen that: after the back surface of the substrate is heated and the surface of the deposited coating is subjected to strengthening treatment, pores in the coating are reduced, a layered structure in the coating is reduced, the density of the coating is obviously improved, and the microstructure of the coating is obviously improved.
Example 1:
the atomized spherical Inconel powder is used as spraying powder (AMPERIT380, HC Starck GmbH), and the particle size is 15-45 μm. TP347H heat-resistant steel (1Cr19Ni11Nb) was used as a base material, and 16-mesh white corundum sand was subjected to sand blasting under a compressed air pressure of 0.8MPa before spraying. Using M3TMtype-HVAF spray system (Uniquecoat, USA) coatings were prepared under the parameters as shown in table 1. Before spraying, the substrate is preheated to 350 ℃ and then the coating is sprayed, and in the spraying process, the substrate is always kept in a 350 ℃ heating state. After the surface of the base material is sprayed for one time, carrying out laser shock strengthening on the surface of the deposited coating, wherein the laser shock strengthening parameters are as follows: the laser power density is 0.6GW/cm2The pulse frequency was 5 Hz. And after laser shock, continuing the next spraying and laser shock strengthening treatment, wherein the parameters of each spraying and laser strengthening treatment are the same as those of the first spraying and laser shock strengthening treatment. The above steps were repeated until the coating thickness became 200 μm and was stopped. And carrying out metallographic phase sample preparation on the prepared coating and observing a microstructure under a scanning electron microscope. The results show that the prepared coating has fewer pores, the layered structure in the coating is partially disappeared, and the coating is compact.
TABLE 1 spray parameters for Inconel 625 coatings
Example 2:
TP347H heat-resistant steel (1Cr19Ni11Nb) was used as a base material, and 16-mesh white corundum sand was subjected to sand blasting under a compressed air pressure of 0.8MPa before spraying. The melting crushed 8YSZ ceramic powder is selected, and the ceramic coating is prepared by APS spraying technology under the spraying parameter conditions shown in the table 2. Before spraying, the substrate is preheated to 700 ℃ and then starts to be sprayed with the coating, and the substrate is always kept in a 700 ℃ heating state in the spraying process. After the surface of the substrate is sprayed in one pass, the surface of the deposited coating is shot peened using ceramic shot (ZrO with a chemical composition of approximately 67%)231% of SiO2And 2% of Al2O3The main impurities are melted, atomized, dried, selected and screened, and the working pressure of the ceramic pill is 0.5 MPa. And after shot peening, continuing the next spraying and shot peening treatment, wherein the parameters of each spraying and shot peening treatment are the same as those of the first spraying and shot peening treatment. The above steps were repeated until the coating thickness was 150 μm and stopped. And carrying out metallographic phase sample preparation on the prepared coating and observing a microstructure under a scanning electron microscope. The results show that the prepared coating has fewer pores, the layered structure in the coating is partially disappeared, and the coating is compact.
TABLE 2 APS spray 8YSZ coating parameters
Claims (6)
1. A method of modifying the microstructure of a coating, comprising: the method comprises the following steps:
step 1: before the coating is prepared, degreasing the surface of the base material, and then sandblasting the surface to the required roughness;
step 2: after the sand blasting is finished, the back surface of the base material is heated before spraying, and then spraying is started; in the spraying process, the back surface of the base material is kept heated all the time;
and step 3: strengthening the surface of the deposited coating in the spraying process;
and 4, step 4: repeating the step 2 and the step 3 until the coating reaches the preset thickness, and stopping spraying;
and 5: and after the spraying is stopped, the heating of the back surface of the base material is slowly stopped, and the temperature is kept to be gradually reduced in the stopping process.
2. A method of modifying the microstructure of a coating according to claim 1, wherein: the heating mode of the back surface of the base material adopts oxyacetylene flame heating or electromagnetic induction heating.
3. A method of modifying the microstructure of a coating according to claim 1, wherein: the back heating temperature of the base material is determined according to the type of the powder to be sprayed, the back heating temperature of the ceramic powder base material is 600-700 ℃, and the back heating temperature of the metal powder base material is 350-450 ℃.
4. A method of modifying the microstructure of a coating according to claim 1, wherein: the strengthening treatment is determined according to the type of the powder to be sprayed, the ceramic powder is sprayed and strengthened by adopting a shot blasting process, and the metal powder is sprayed and strengthened by adopting laser shock.
5. A method of modifying the microstructure of a coating according to claim 4, wherein said coating is applied to a substrate, said method comprising: the shot blasting process adopts ceramic shots, and the chemical components of the ceramic shots are 67 percent of ZrO231% of SiO2And 2% of Al2O3The inclusions are prepared by melting, atomizing, drying, selecting round and screening, and the hardness of the inclusions is equal to HRC 57-63; the working pressure of the ceramic pill is 0.4-0.6 MPa.
6. A method of modifying the microstructure of a coating according to claim 4, wherein said coating is applied to a substrate, said method comprising: the laser power density of the laser shock peening is 0.4GW/cm2～1.2GW/cm2The pulse frequency is adjusted between 0Hz and 10 Hz.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113186526A (en) * | 2021-04-30 | 2021-07-30 | 广东省科学院新材料研究所 | Metal coating and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100136296A1 (en) * | 2006-11-30 | 2010-06-03 | United Technologies Corporation | Densification of coating using laser peening |
| CN101760719A (en) * | 2010-02-05 | 2010-06-30 | 江苏大学 | Method and device of laser impact and thermal spraying composite coating preparation |
| US20160237573A1 (en) * | 2013-10-24 | 2016-08-18 | United Technologies Corporation | Method for enhancing bond strength through in-situ peening |
| CN106065457A (en) * | 2016-07-29 | 2016-11-02 | 西安交通大学 | Deposited particles combines sufficient plasma spraying ceramic of compact coating and preparation method thereof |
| CN107164731A (en) * | 2017-05-26 | 2017-09-15 | 广东省新材料研究所 | A kind of preparation method of Mg alloy surface aluminium composite armor |
| CN108842124A (en) * | 2018-06-04 | 2018-11-20 | 重庆市科学技术研究院 | A kind of method of laser melting coating reparation and reinforcing mold |
| CN109468572A (en) * | 2018-12-06 | 2019-03-15 | 苏州热工研究院有限公司 | The compound method for increasing material remanufacturing system prepares coating of thermal spraying/laser |
-
2020
- 2020-10-16 CN CN202011106777.8A patent/CN112275593B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100136296A1 (en) * | 2006-11-30 | 2010-06-03 | United Technologies Corporation | Densification of coating using laser peening |
| CN101760719A (en) * | 2010-02-05 | 2010-06-30 | 江苏大学 | Method and device of laser impact and thermal spraying composite coating preparation |
| US20160237573A1 (en) * | 2013-10-24 | 2016-08-18 | United Technologies Corporation | Method for enhancing bond strength through in-situ peening |
| CN106065457A (en) * | 2016-07-29 | 2016-11-02 | 西安交通大学 | Deposited particles combines sufficient plasma spraying ceramic of compact coating and preparation method thereof |
| CN107164731A (en) * | 2017-05-26 | 2017-09-15 | 广东省新材料研究所 | A kind of preparation method of Mg alloy surface aluminium composite armor |
| CN108842124A (en) * | 2018-06-04 | 2018-11-20 | 重庆市科学技术研究院 | A kind of method of laser melting coating reparation and reinforcing mold |
| CN109468572A (en) * | 2018-12-06 | 2019-03-15 | 苏州热工研究院有限公司 | The compound method for increasing material remanufacturing system prepares coating of thermal spraying/laser |
Non-Patent Citations (1)
| Title |
|---|
| 商俊超等: "微粒轰击Fe基非晶电弧喷涂层性能强化", 《中国表面工程》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113186526A (en) * | 2021-04-30 | 2021-07-30 | 广东省科学院新材料研究所 | Metal coating and preparation method thereof |
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