CN111996481B - Preparation method of YSZ/Cu metal ceramic composite coating - Google Patents

Abstract

The invention relates to a preparation method of a YSZ/Cu metal-ceramic composite coating, belonging to the technical field of thermal spraying. The method is to first prepare a NiCrAlY layer on the sandblasted substrate, and then use an atmospheric plasma spraying process to spray the YSZ@Cu metal-ceramic composite powder with a core-shell structure on the NiCrAlY layer to prepare a YSZ/Cu metal-ceramic composite coating. In the present invention, by optimizing the process parameters of atmospheric plasma spraying, the two phases in the prepared YSZ/Cu metal-ceramic composite coating can be effectively spread, and the Cu phase is in a network structure, so that the two phases are alternately distributed evenly between phases. , so as to realize the precise control of the structure of the YSZ/Cu metal-ceramic composite coating, and solve the problems of uneven distribution of two-phase or multi-phase in the current thermal spraying process and the difficulty of effectively regulating the microstructure of the coating. In the application field of metal-ceramic composite coatings Has broad application prospects.

Description

A kind of preparation method of YSZ/Cu metal ceramic composite coating

technical field

The invention relates to a preparation method of a YSZ/Cu metal-ceramic composite coating, belonging to the technical field of thermal spraying.

Background technique

Due to its excellent mechanical and physical properties, metal-ceramic composite coatings play an important role in protecting parts and components in different working environments. Usually, metal-ceramic composite coatings with specific functions are prepared on the surface of the substrate, thereby reducing the working environment for parts and components. influence to achieve the purpose of protecting the substrate.

In order to further develop cermet composite coatings in different application fields, cermet coatings with controllable structure and excellent properties have attracted the attention of researchers. For the preparation of metal-ceramic composite coatings, at present, two-phase or multi-phase powders are mainly directly mixed to obtain composite powders, or two-phase or multi-phase composite powders are prepared by granulation, and then the thermal spraying process is used to prepare composite powders. Prepare the coating. Due to the difference in the original physical properties between the two or more phases or the uneven subsequent mixing, it is easy to cause irregular phase distribution of the coating, which is not conducive to the effective control of the coating structure during the spraying process. The service life of the coating is affected in the subsequent service process.

SUMMARY OF THE INVENTION

Aiming at the shortcomings of the current metal-ceramic composite coating, the present invention provides a preparation method of a YSZ/Cu metal-ceramic composite coating. The process parameters of plasma spraying can effectively control the microstructure of the coating, and obtain a metal-ceramic composite coating with good two-phase spreading and alternating two-phase distribution, which solves the problem of uneven distribution of two or more phases in the current thermal spraying process. It is difficult to effectively control the microstructure of the coating, which is beneficial to improve the performance of the metal-ceramic composite coating.

The purpose of the present invention is achieved through the following technical solutions.

A preparation method of YSZ/Cu metal-ceramic composite coating, the method steps are as follows,

(1) Sandblasting the substrate, the sandblasting pressure is 0.5Mpa～0.7Mpa, the sandblasting abrasive is selected from 25-30 mesh brown corundum, and the sandblasting time is 2min～4min;

(2) Clean the impurities remaining on the substrate after sandblasting, and dry it to increase the bonding force between the NiCrAlY layer and the substrate; then use the thermal spraying process to prepare the NiCrAlY layer on the substrate;

Further, put the sandblasted substrate into an acetone solution with a concentration of 40g/L～50g/L, carry out ultrasonic cleaning to remove the impurities remaining on the surface of the substrate, and place it to dry at 70°C～80°C;

Further, the substrate is heated to 150 ℃～200 ℃ under the supersonic flame flow, and then the NiCrAlY powder is sprayed on the substrate by the supersonic spraying process. 15m/min～35m/min, powder feeding speed 50g/min～70g/min, oxygen 0.6MPa～1.5MPa, kerosene flow rate 0.3L/min～0.6L/min, carrier gas flow rate 8L/min～15L/min;

Further, the thickness of the NiCrAlY layer is 0.1mm˜0.3mm;

(3) In an argon protective atmosphere, the YSZ@Cu metal-ceramic composite powder was sprayed on the NiCrAlY layer by atmospheric plasma spraying, and a YSZ/Cu metal-ceramic composite coating was formed on the NiCrAlY layer;

Among them, the process parameters of atmospheric plasma spraying are as follows: spraying current 400A～700A, spraying distance 100mm～200mm, spray gun speed 10m/min～30m/min, powder feeding speed 30g/min～50g/min, main air flow 30L/min～ 50L/min, auxiliary gas flow 5.5L/min～8.5L/min, carrier gas flow 5.5L/min～7.5L/min.

Further, the thickness of the YSZ/Cu metal-ceramic composite coating is 0.1 mm˜0.3 mm.

Further, the particle size of the YSZ@Cu cermet composite powder is preferably 45 μm to 66 μm, which can be prepared by the method in Chinese Patent Application No. 201910925416.7.

Further, the flow rate of argon used as the protective gas is preferably 0.1 L/min to 0.3 L/min.

Beneficial effects:

(1) Sandblasting the surface of the substrate not only increases the roughness of the substrate surface, but also removes impurities on the substrate surface, making it easier to achieve effective deposition of the NiCrAlY layer and the YSZ/Cu metal-ceramic composite coating in the subsequent spraying process .

(2) The NiCrAlY layer is prepared by the supersonic flame spraying process, and the YSZ/Cu metal-ceramic composite coating is prepared by the atmospheric plasma spraying, which can improve the deposition efficiency of the NiCrAlY layer and the YSZ/Cu metal-ceramic composite coating. binding force.

(3) Due to the large physical property difference between the YSZ phase and the Cu phase, in the process of the plasma torch, there are differences in the melting states of the two phases during spraying. By optimizing the process parameters of atmospheric plasma spraying, the prepared YSZ/ The two phases in the Cu cermet composite coating are effectively spread, and the Cu phase has a network structure, which realizes the even distribution of the two phases alternately and evenly, so as to realize the precise control of the structure of the YSZ/Cu cermet composite coating, which is beneficial to Expand the application scenarios of YSZ/Cu cermet composite coating.

(4) The method of the present invention is simple in operation and low in cost. The YSZ@Cu metal-ceramic composite powder with a core-shell structure is used as the raw material, which avoids the subsequent related processing of two-phase or multi-phase powder, and solves the problem of current thermal problems. The problem of uneven distribution of two or more phases in the spraying process has broad application prospects in the application field of metal-ceramic composite coatings.

Description of drawings

FIG. 1 is a scanning electron microscope (SEM) image of the surface of the YSZ/Cu cermet composite coating prepared in Example 1. FIG.

FIG. 2 is a scanning electron microscope (SEM) image of the cross section of the YSZ/Cu cermet composite coating prepared in Example 1. FIG.

3 is a scanning electron microscope (SEM) image of the cross-section of the YSZ/Cu cermet composite coating prepared in Example 1 and its EDS element distribution map.

4 is a comparison diagram of the XRD (X-ray diffraction) pattern of the YSZ/Cu cermet composite coating prepared in Example 1 and the standard XRD patterns of CuO, Cu ₂ O, Cu and YSZ.

FIG. 5 is a scanning electron microscope (SEM) image of the surface of the YSZ/Cu cermet composite coating prepared in Example 2. FIG.

FIG. 6 is a scanning electron microscope (SEM) image of the cross-section of the YSZ/Cu cermet composite coating prepared in Example 2. FIG.

7 is a scanning electron microscope (SEM) image of the cross-section of the YSZ/Cu cermet composite coating prepared in Example 2 and its EDS element distribution map.

8 is a comparison diagram of the XRD (X-ray diffraction) pattern of the YSZ/Cu cermet composite coating prepared in Example 2 and the standard XRD patterns of CuO, Cu ₂ O, Cu and YSZ.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, wherein the methods are conventional methods unless otherwise specified, and the raw materials can be obtained from open commercial channels unless otherwise specified.

In the following examples, the involved YSZ@Cu metal-ceramic composite powder was prepared with reference to the method of Example 1 in Chinese Patent Application No. 201910925416.7, and the information of the main instruments involved is shown in Table 1.

Table 1

Example 1

(1) Select 25 mesh brown corundum as the sandblasting abrasive, put the stainless steel substrate into the sandblasting machine, adjust the compressed air pressure in the machine to 0.5Mpa, and blast the substrate for 2 minutes to increase the surface roughness of the substrate. Remove impurities such as oil stains on the surface of the substrate;

(2) Put the sandblasted substrate into an acetone solution with a concentration of 30g/L, and then transfer it to an ultrasonic cleaner with a frequency of 250MHz for ultrasonic cleaning for 0.5h to remove the remaining impurities on the substrate after sandblasting. Put it into a blast drying oven at 70°C to dry;

(3) Heat the dried substrate to 200°C under the supersonic flame flow, add the NiCrAlY powder with a particle size of 50 μm to 75 μm into the powder feeder, and spray the NiCrAlY powder on the substrate by the supersonic flame spraying process , a NiCrAlY layer with a thickness of 0.1 mm is formed on the substrate;

Among them, the process parameters of supersonic spraying are as follows: spraying distance 200mm, spray gun speed 15m/min, powder feeding speed 50g/min, oxygen 0.6MPa, kerosene flow rate 0.3L/min, carrier gas (nitrogen) flow rate 8L/min;

(4) The YSZ@Cu cermet composite powder with a particle size of 45 μm to 66 μm was added to the powder feeder, and the YSZ@Cu cermet composite powder was sprayed on the NiCrAlY layer by the atmospheric plasma spraying process, and formed on the NiCrAlY layer. YSZ/Cu metal-ceramic composite coating with a thickness of 0.1mm;

Among them, the process parameters of atmospheric plasma spraying are as follows: spraying current 400A, spraying distance 100mm, spray gun speed 10m/min, powder feeding speed 30g/min, main gas (argon) flow 30L/min, auxiliary gas (hydrogen) flow 5.5L /min, the flow rate of carrier gas (argon) is 5.5L/min.

It can be seen from Figures 1 to 2 that the surface of the YSZ/Cu metal-ceramic composite coating presents a good lath shape, with a uniform distribution of microstructure and fine cracks and tiny pores. A small amount of unmelted particles that are not completely melted and have a low degree of spreading are produced around the spread molten particles with different degrees of molten droplet splashing. At this time, the fully spread molten particles can easily fill the gap between layers, and achieve layer-to-layer The effective bonding between them, thereby improving the density and bonding strength of the coating. It can be seen from Figure 3 that the cross-sectional morphology of the YSZ/Cu cermet composite coating is composed of different structures composed of a complete melting zone and a partial semi-melting zone, and there are small pores; at the same time, the YSZ phase and the Cu phase Both of them achieve good spreading, and the two present a microstructure with staggered distribution and tight bonding at the interface, and there is a good metallurgical interface between them. It can be seen from Figure 4 that the characteristic peaks of YSZ and Cu two phases clearly exist in the YSZ/Cu cermet composite coating, and it can be judged that its phase structure is a mixture of two phases, indicating that there is no obvious oxidation during the spraying process. The generation of phase and second phase indicates that adjusting the parameters of the plasma spraying process plays an important role in obtaining YSZ/Cu cermet composite coatings with good phase composition and excellent microstructure.

Example 2

(1) Select 30-mesh brown corundum as the sandblasting abrasive, put the stainless steel substrate into the sandblasting machine, adjust the compressed air pressure in the machine to 0.7Mpa, and blast the substrate for 4 minutes to increase the surface roughness of the substrate. Remove impurities such as oil stains on the surface of the substrate;

(2) Put the sandblasted substrate into an acetone solution with a concentration of 50g/L, and then transfer it to an ultrasonic cleaner with a frequency of 250MHz for ultrasonic cleaning for 1 hour to remove the impurities remaining in the substrate after sandblasting. Dry in a blast drying oven at 80°C;

(3) Heat the dried substrate to 200°C under the supersonic flame flow, add the NiCrAlY powder with a particle size of 50 μm to 75 μm into the powder feeder, and spray the NiCrAlY powder on the substrate by the supersonic flame spraying process , a NiCrAlY layer with a thickness of 0.3mm is formed on the substrate;

Among them, the process parameters of supersonic spraying are as follows: spraying distance 400mm, spray gun speed 35m/min, powder feeding speed 70g/min, oxygen 1.5MPa, kerosene flow 0.6L/min, carrier gas (nitrogen) flow 15L/min;

(4) The YSZ@Cu cermet composite powder with a particle size of 45 μm to 66 μm was added to the powder feeder, and the YSZ@Cu cermet composite powder was sprayed on the NiCrAlY layer by the atmospheric plasma spraying process, and formed on the NiCrAlY layer. YSZ/Cu metal-ceramic composite coating with a thickness of 0.3mm;

Among them, the process parameters of atmospheric plasma spraying are as follows: spraying current 700A, spraying distance 200mm, spray gun speed 30m/min, powder feeding speed 50g/min, main gas (argon) flow 50L/min, auxiliary gas (hydrogen) flow 8.5L /min, the flow rate of carrier gas (argon) is 7.5L/min.

It can be seen from Figures 5 to 6 that the surface of the YSZ/Cu metal-ceramic composite coating presents a good lath shape, the structure is uniformly distributed, and there are fine cracks and tiny pores. A small amount of unmelted particles that are not completely melted and have a low degree of spreading are produced around the spread molten particles with different degrees of molten droplet splashing. At this time, the fully spread molten particles can easily fill the gap between layers, and achieve layer-to-layer The effective bonding between them, thereby improving the density and bonding strength of the coating. It can be seen from Figure 7 that the cross-sectional morphology of the YSZ/Cu cermet composite coating is composed of different microstructures composed of complete melting zone and partial semi-melting zone, and there are small pores; at the same time, YSZ phase and Cu phase Both of them achieve good spreading, and the two present a microstructure with staggered distribution and tight bonding at the interface, and there is a good metallurgical interface between them. It can be seen from Fig. 8 that the characteristic peaks of YSZ and Cu two phases clearly exist in the YSZ/Cu cermet composite coating, and it can be judged that its phase structure is a mixture of two phases, indicating that there is no obvious oxidation during the spraying process. The generation of phase and second phase indicates that adjusting the parameters of the plasma spraying process plays an important role in obtaining YSZ/Cu cermet composite coatings with good phase composition and excellent microstructure.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. A preparation method of a YSZ/Cu metal ceramic composite coating is characterized by comprising the following steps: the steps of the method are as follows,

(1) carrying out sand blasting treatment on the matrix, wherein the sand blasting pressure is 0.5-0.7 Mpa, the sand blasting abrasive material is brown corundum with 25-30 meshes, and the sand blasting time is 2-4 min;

(2) cleaning the residual impurities on the matrix after sand blasting, drying, and preparing a NiCrAlY layer on the matrix by adopting a thermal spraying process;

(3) spraying YSZ @ Cu metal ceramic composite powder on the NiCrAlY layer by adopting atmospheric plasma spraying under the protection of argon, and forming a YSZ/Cu metal ceramic composite coating on the NiCrAlY layer;

wherein, the technological parameters of the atmospheric plasma spraying are as follows: the spraying current is 400A-700A, the spraying distance is 100 mm-200 mm, the speed of a spray gun is 10 m/min-30 m/min, the powder feeding speed is 30 g/min-50 g/min, the main gas flow is 30L/min-50L/min, the auxiliary gas flow is 5.5L/min-8.5L/min, the carrier gas flow is 5.5L/min-7.5L/min, and the argon gas flow for protective gas is 0.1L/min-0.3L/min.

2. The preparation method of YSZ/Cu metal ceramic composite coating according to claim 1, characterized in that: putting the matrix after sand blasting into acetone solution with the concentration of 40 g/L-50 g/L for ultrasonic cleaning to remove residual impurities on the surface of the matrix, and drying at 70-80 ℃.

3. The preparation method of YSZ/Cu metal ceramic composite coating according to claim 1, characterized in that: heating the substrate to 150-200 ℃ under supersonic flame flow, and spraying NiCrAlY powder on the substrate by adopting a supersonic spraying process;

wherein the technological parameters of the supersonic spraying are as follows: the spraying distance is 200 mm-400 mm, the speed of a spray gun is 15 m/min-35 m/min, the powder feeding speed is 50 g/min-70 g/min, the oxygen is 0.6 MPa-1.5 MPa, the kerosene flow is 0.3L/min-0.6L/min, and the carrier gas flow is 8L/min-15L/min.

4. The preparation method of YSZ/Cu metal ceramic composite coating according to claim 1, characterized in that: the thickness of the NiCrAlY layer is 0.1 mm-0.3 mm.

5. The preparation method of YSZ/Cu metal ceramic composite coating according to claim 1, characterized in that: the thickness of the YSZ/Cu metal ceramic composite coating is 0.1 mm-0.3 mm.

6. The preparation method of YSZ/Cu metal ceramic composite coating according to claim 1, characterized in that: YSZ @ Cu metal ceramic composite powder is prepared by adopting the method in Chinese patent application 201910925416.7.

7. The preparation method of YSZ/Cu metal ceramic composite coating according to claim 1, characterized in that: the grain diameter of the YSZ @ Cu metal ceramic composite powder is 45-66 mu m.

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