CN114214555B - A kind of anti-cavitation corrosion-resistant metal-ceramic matrix composite material and preparation method thereof - Google Patents

Abstract

The invention discloses a preparation method of a cavitation-corrosion-resistant metal-ceramic matrix composite, which comprises the following steps: (1) preparing a composite prefabricated part by taking a metal material, a ceramic material and a rare earth material as raw materials; in the composite prefabricated member, the volume ratio of the metal phase to the ceramic phase is 5-95: 95-5; the addition amount of the rare earth material is 0.1-10% of the total mass of the metal material and the ceramic material; (2) and (2) carrying out laser remelting treatment on the composite prefabricated part prepared in the step (1). The introduction of the rare earth material reduces the melting point of the metal-ceramic matrix composite material, improves the laser absorption rate of the material, and improves the cavitation corrosion resistance and the corrosion resistance of the metal-ceramic matrix composite material. In addition, the metal material, the ceramic and the rare earth material can play a synergistic role in a cavitation-corrosion environment, so that the prepared metal-ceramic matrix composite material has excellent cavitation-corrosion resistance and corrosion resistance.

Description

A kind of anti-cavitation corrosion-resistant metal-ceramic matrix composite material and preparation method thereof

technical field

The invention relates to the technical field of metal-ceramic composite material preparation, in particular to a cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material and a preparation method thereof.

Background technique

Cavitation, or cavitation, is a phenomenon in which vapor bubbles are generated due to a decrease in the local pressure due to a fluid flow rate too fast, resulting in a decrease in the saturated vapor pressure. This phenomenon is common in overcurrent components such as propellers and turbines. The collapse of the cavitation will generate microjets and shock waves with extremely high energy density. When these micro-jets and shock waves continue to bombard the surface of the material, the stress will gradually accumulate, causing the material to plastically deform and eventually lead to the peeling of the material. The material wear caused by micro-jets and shock waves through cavitation rupture is cavitation erosion, which is one of the main reasons for limiting the service life of wetted parts. In addition, when the wetted parts operate in a corrosive environment such as seawater, corrosion cannot be avoided, and the synergistic effect of corrosion and cavitation will further cause damage to the wetted parts.

At present, the treatment of anti-cavitation corrosion of materials is usually to add a metal-ceramic composite coating on the surface of the material to strengthen its anti-cavitation corrosion ability. The corresponding technologies include: laser surface cladding, laser surface alloying, laser surface fusion and other laser surface modification technologies. This type of technology is based on the thermal action of high-energy laser radiation to prepare different types of anti-cavitation corrosion coatings on the surface of the material. For example, the Chinese patent document with publication number CN106756996A provides a rare earth Modified laser cladding layer, on titanium alloy substrate, laser cladding powder composed of Ni60A nickel-based alloy powder, B ₄ C or nickel-clad B ₄ C (Ni@B ₄ C), and micro or nano-scale rare earth oxides The rare earth modified laser cladding layer is prepared, and the rare earth modified laser cladding layer can obviously improve the wear resistance of the substrate. However, the cost of this method is high, and it is difficult to popularize and apply in practice.

Laser remelting is to use a laser beam to melt the surface without introducing new elements to achieve the purpose of improving the surface structure. Using laser remelting can release impurities, pores, and compounds to improve the defects on the surface of the material. At the same time, due to the quenching, the material in the molten pool will form a completely different microstructure from the traditional casting material, improving the mechanical properties of the material surface.

The Chinese patent document with publication number CN110699626A discloses a laser remelting method for anti-cavitation thermal spraying cermet coating, and the thermal spraying is plasma spraying or supersonic flame spraying, and the obtained coating has very good properties. Good cavitation resistance, Chinese patent document with publication number CN110699682A discloses a method for preparing anti-cavitation coating using cold spraying and laser remelting composite process, the method uses cold spraying technology to deposit a layer on the substrate Thicker metal-ceramic composite coating, and then use the coating after laser remelting treatment and the coating after cold spraying to form a transition layer, the obtained coating also has very good cavitation resistance, but the above two inventions are not The corrosion resistance of the coatings has not been studied.

SUMMARY OF THE INVENTION

The invention provides a preparation method of a cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material. The process is simple. Metal materials, ceramic materials and rare earth materials are used as raw materials, and a laser remelting treatment process is supplemented. Cavitation and corrosion resistance of ceramic matrix composites.

The specific technical solutions adopted are as follows:

A preparation method of a cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material, comprising the following steps:

(1) Using metal materials, ceramic materials and rare earth materials as raw materials to prepare composite preforms; in the composite preforms, the volume ratio of metal phase and ceramic phase is 5-95:95-5; the amount of rare earth material added is the metal material 0.1-10% of the total mass of the ceramic material;

(2) Laser remelting is performed on the composite preform obtained in step (1).

The invention selects metal materials, ceramic materials and rare earth materials as raw materials, and is supplemented by laser remelting treatment to prepare cavitation-resistant and corrosion-resistant metal-ceramic matrix composite materials; The metal-ceramic matrix composite material plays a major role in the corrosion, while the metal material mainly plays the role of bonding the ceramic and provides support for the ceramic. The addition of rare earth elements can further improve the cavitation resistance and corrosion resistance of the metal-ceramic matrix composite, that is, Metal materials, ceramics and rare earth materials can play a synergistic role in cavitation-corrosion environment, so that the prepared metal-ceramic matrix composites have excellent anti-cavitation and corrosion resistance properties.

The metal material includes metal Ni, metal Co, metal Cr, Ni-based alloy, Co-based alloy, Cr-based alloy, Ti-based alloy, duplex stainless steel, aluminum bronze or nickel aluminum bronze.

Suitable metal material raw materials can be selected according to the application scenario of the prepared cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material. When the application scenario is inland environments such as rivers, lakes and reservoirs, the metal materials are preferably metal Ni and metal Co. , metal Cr, Ni-based alloy, Co-based alloy, Cr-based alloy or duplex stainless steel; when the application scenario is marine environment, the metal material is preferably aluminum bronze or nickel-aluminum bronze; when it is other special application scenarios, the metal material can be Use Ti-based alloys.

Preferably, the ceramic material is carbide ceramic and/or oxide ceramic, and the carbide ceramic includes tungsten carbide, niobium carbide, tantalum carbide, hafnium carbide or titanium carbide.

Preferably, the rare earth material includes a rare earth element or a rare earth element compound; more preferably, a rare earth oxide.

First, the addition of rare earth materials can reduce the melting point of the metal-ceramic matrix composite material, and at the same time increase the material's absorption rate of laser light, effectively reducing the power consumption during the laser remelting process; secondly, the presence of rare earth materials can reduce the solid-liquid interface. surface energy and provide more nuclei, that is, the presence of rare earth materials can make the metal-ceramic matrix composites form finer grains during the laser remelting process, and finer grains mean stronger Surface mechanical properties, that is, the addition of rare earth materials can improve the cavitation resistance of the metal-ceramic matrix composite; finally, the presence of rare earth materials can make the metal-ceramic matrix composite have a lower corrosion current density and in a corrosive environment. It is easier to form a passivation film under lower conditions, that is, the addition of rare earth materials can improve the corrosion resistance of the metal-ceramic matrix composite material.

Preferably, the ceramic material is tungsten carbide or a mixture of tungsten carbide and oxide ceramics; the rare earth material is cerium oxide or lanthanum oxide; in the composite preform, the volume ratio of the metal phase to the ceramic phase is 60-80: 40-20; the amount of rare earth material added is 1-5% of the total mass of the metal material and the ceramic material. When the above-mentioned raw materials and parameters are selected, a metal-ceramic matrix composite material with excellent cavitation and corrosion resistance properties can be obtained at a lower cost.

In step (1), the composite preform can be obtained by casting, forging, powder metallurgy or processing, and the processing methods include turning, pliers, milling, planing, inserting, grinding, drilling, boring, punching, sawing, electric corrosion , heat treatment.

Preferably, the composite preform obtained in step (1) is pretreated and then laser remelted, and the pretreatment includes at least one of sandblasting and roughening, rust removal and oil removal. Roughening by sandblasting can improve the absorption rate of laser light on the surface of the preform.

Further preferably, the pretreatment method is: using ethanol, acetone, etc. to clean the dirt on the surface of the composite preform, drying and then using a sandblasting machine to carry out sandblasting and roughening treatment, and the process of sandblasting and roughening treatment. The parameters are: air pressure 0.3～1.0MPa, sand blasting time 10s～2min, and the particle size of sand blasting is 40～200 meshes.

Preferably, the laser remelting treatment parameters are: the power is 200-3000W; the diameter of the light spot is 0.3-3mm; the moving speed of the light spot is 100-500mm/min; the protective gas is high-purity nitrogen or argon; the protective gas pressure is 0.4～1.5MPa; flow rate is 4～8L/min.

The invention also provides the anti-cavitation corrosion-resistant metal-ceramic matrix composite material prepared by the preparation method of the anti-cavitation corrosion-resistant metal-ceramic matrix composite material, and the anti-cavitation corrosion-resistant metal-ceramic matrix composite material has Cavitation and corrosion resistant surface.

The cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material can be used for various overcurrent components, such as rudders, propellers, turbine blades, etc. Use efficiency and prolong the service time of equipment.

Compared with the prior art, the beneficial effects of the present invention are:

(1) Compared with the method of laser treatment after introducing the coating, the method of the present invention reduces the number of process steps and can effectively reduce the treatment cost.

(2) The introduction of rare earth materials reduces the melting point of metal-ceramic matrix composites, and at the same time increases the material's absorption rate of laser light, which effectively reduces the power consumption during laser remelting; and the introduction of rare earth materials improves the metal-ceramic matrix. Cavitation and corrosion resistance of composite materials.

(3) In a corrosive environment, cavitation will also be accelerated. The anti-cavitation and anti-corrosion metal-ceramic matrix composite material prepared by the method of the present invention has excellent surface anti-cavitation and corrosion resistance, and can be applied to various types of overcurrent components , such as rudders, propellers, turbine blades, etc., which greatly reduces the maintenance frequency of components due to cavitation and corrosion damage, improves the efficiency of equipment use, and prolongs the service time of equipment.

Description of drawings

FIG. 1 is a cross-sectional SEM picture of the cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material prepared in Example 1. FIG.

FIG. 2 is a surface SEM picture of the cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material prepared in Example 1. FIG.

3 is a SEM picture of the surface of the anti-cavitation and corrosion-resistant metal-ceramic matrix composite material prepared in Example 1 after 10h of anti-cavitation corrosion test in artificial seawater.

FIG. 4 is a cross-sectional SEM picture of the cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material prepared in Example 2. FIG.

Detailed ways

The present invention will be further illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention.

Example 1

In this embodiment, the metal material is nickel powder, the ceramic material is tungsten carbide powder, and the rare earth material is cerium oxide powder. The steps of preparing the cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material include:

(1) Mix the nickel powder and the tungsten carbide powder at a volume ratio of 70±5% and 30±5% (the required mass can be calculated from the theoretical density), and then add 2±0.5% of the total mass of the nickel powder and the tungsten carbide powder. Cerium oxide powder, mixed uniformly, and then poured into the mold;

(2) The mold is sent into a vacuum sintering furnace, and the powder is fully sintered under a pressure of 40MPa and a temperature of 1200°C for 1 hour; then it is naturally cooled, and the formed composite preform is taken out;

(3) Clean the prefab in step (2) with ethanol, and after drying, use 60-mesh brown corundum sand to roughen its surface, the air pressure of sandblasting is 1MPa, and the sandblasting time is 60 seconds to improve the surface resistance to laser absorption rate;

(4) The surface of the preform is then subjected to laser remelting treatment to prepare a cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material. The parameters of laser remelting are: laser power 300W, laser spot diameter 0.5mm, and spot moving speed 250mm /s, the laser path interval is 0.25mm, and high-purity nitrogen gas is used for side blowing, the protective gas pressure is 0.8MPa, and the flow rate is 6L/min.

Example 2

In this embodiment, the metal material is bulk nickel and flake chromium, the ceramic material is tungsten carbide powder, and the rare earth material is lanthanum oxide powder. The steps of preparing the cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material include:

(1) Mix the bulk nickel, flake chromium, and tungsten carbide powders according to the volume ratio of 15±5%, 55±5%, 30±5%, and then add the total mass of the block nickel, flake chromium and tungsten carbide powders 3±1% lanthanum oxide powder, uniformly mixed, then poured into the crucible of the vacuum induction melting furnace for heating;

(2) when the temperature reaches 2400°C, keep it for 3 minutes, then pour the molten material in the crucible into the copper mold, and after it is completely cooled, take out the formed composite preform;

(3) Clean the prefab in step (2) with ethanol, and after drying, use 60-mesh brown corundum sand to roughen its surface, the air pressure of sandblasting is 1MPa, and the sandblasting time is 60 seconds to improve the surface resistance to laser absorption rate;

(4) The surface of the preform is then subjected to laser remelting to prepare a cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material. The parameters of laser remelting are: laser power 400W, laser spot diameter 0.5mm, and spot moving speed 300mm /s, the laser path interval is 0.25mm, and high-purity nitrogen gas is used for side blowing, the protective gas pressure is 1.0MPa, and the flow rate is 6L/min.

Comparative Example 1

The preparation method of the metal-ceramic matrix composite material in Comparative Example 1 is the same as that in Example 1, except that the raw material in Comparative Example does not add cerium oxide powder, a rare earth material.

Comparative Example 2

The preparation method of the metal-ceramic matrix composite material in Comparative Example 2 is the same as that in Example 2, except that the raw material in Comparative Example does not add lanthanum oxide powder, a rare earth material.

Sample analysis

(1) Morphology analysis

The morphology of the cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material of Example 1 was analyzed. The cavitation corrosion-resistant surface has the characteristics of uniform, smooth, dense and less defects. The brighter part is tungsten carbide, and the grayer part is nickel. In addition, it can be seen from FIG. 1 that the surface of the cavitation-resistant and corrosion-resistant metal-ceramic matrix composite is divided into two layers, and the remelted area in the upper part has a microstructure that is significantly different from the unremelted area in the lower part. Compared to the lower part, the tungsten carbide grains in the upper part become finer and fully compatible with nickel with fewer defects. This makes the surface structure of the coating dense, thereby greatly improving the cavitation and corrosion resistance of the metal-ceramic matrix composite.

The morphology of the cross-section of the anti-cavitation corrosion-resistant metal-ceramic matrix composite material in Example 2 was analyzed. The results are shown in Figure 4. Similar to Example 1, the surface of the anti-cavitation corrosion-resistant metal-ceramic matrix composite material was It is divided into two layers. The upper remelted area has a microstructure that is significantly different from the lower unremelted area. The cavitation and corrosion resistant surface formed by the laser surface remelting process is obviously uniform, compact, and has few defects, which can improve metal - Cavitation and corrosion resistance of ceramic matrix composites.

(2) Cavitation resistance and corrosion resistance test

① Take 316L stainless steel as control sample 1, the preform without laser remelting treatment in step (3) in Example 1 as control sample 2, the metal-ceramic matrix composite material of Cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material is sample 1.

The specific test methods for cavitation resistance and corrosion resistance are as follows: use 2000-mesh sandpaper to grind sample 1 and control samples 1 to 3, and use ultrasonic cavitation equipment to test the cavitation resistance of materials under artificial seawater according to the ASTM-G32-2010 standard. and corrosion resistance.

The frequency of the ultrasonic cavitation equipment is set to 20KHz, the amplitude is ±50μm, the distance between the ultrasonic cavitation head and the sample surface is 1mm, the cavitation head is immersed in water for 23±2mm, the test solution is artificial seawater, and the water temperature is kept at 25±2℃ .

After the cavitation-resistant and corrosion-resistant metal-ceramic matrix composite material of Example 1 is corroded by ultrasonic cavitation for 10 hours, the surface scanning electron microscope image is shown in Figure 3, and the surface of the material has only some small holes. The volume loss of the material after 10 hours of cavitation and corrosion tests was counted, and it was found that the volume loss of sample 1 (the cavitation and corrosion-resistant metal-ceramic matrix composite material of Example 1) was about the same as that of control sample 3 (the metal- Ceramic matrix composite material) is two-thirds of the control sample 1 (316L stainless steel), and is ten-thousandth of the control sample 2 (the preform without laser remelting in step (3) in Example 1). one part.

② Take 316L stainless steel as control sample 4, the prefabricated part without laser remelting treatment in step (3) in Example 2 as control sample 5, the metal-ceramic matrix composite material of The cavitation-resistant and corrosion-resistant metal-ceramic matrix composite is sample 2.

The test method of anti-cavitation and corrosion resistance is the same as above, after 10 hours of ultrasonic cavitation corrosion, the material volume loss after 10 hours of cavitation and corrosion tests is counted, and it is found that sample 2 (the anti-cavitation and corrosion-resistant metal of Example 2- The volume loss of the ceramic matrix composite material) is about one-half of the control sample 6 (the metal-ceramic matrix composite material of the comparative example 2), one-fifth of the control sample 4 (316L stainless steel), and the control sample 5 ( Step (3) in Example 2 is one tenth of the preform without laser remelting).

The above test results of anti-cavitation and corrosion resistance show that the anti-cavitation and corrosion-resistant metal-ceramic matrix composite material prepared by the method of the present invention has excellent anti-cavitation and corrosion resistance, and the introduction of rare earth elements further improves its cavitation resistance. and corrosion resistance.

The above-mentioned embodiments describe the technical solutions of the present invention in detail. It should be understood that the above-mentioned embodiments are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions or similar substitutions, etc., shall be included within the protection scope of the present invention.

Claims (7)

1. The preparation method of the cavitation-erosion-resistant corrosion-resistant metal-ceramic matrix composite is characterized by comprising the following steps of:

(1) preparing a composite prefabricated part by taking a metal material, a ceramic material and a rare earth material as raw materials;

(2) carrying out laser remelting treatment on the composite prefabricated part prepared in the step (1);

the ceramic material is carbide ceramic; the carbide ceramic comprises tungsten carbide, niobium carbide, tantalum carbide, hafnium carbide or titanium carbide; the rare earth material is cerium oxide or lanthanum oxide;

in the composite prefabricated part, the volume ratio of the metal phase to the ceramic phase is 60-80: 40-20; the adding amount of the rare earth material is 3-5% of the total mass of the metal material and the ceramic material;

the metal material comprises metal Ni, metal Co, metal Cr, Ni-based alloy, Co-based alloy, Cr-based alloy, Ti-based alloy, aluminum bronze or nickel aluminum bronze;

in step (1), the composite preform may be obtained by casting, forging or powder metallurgy.

2. The method of claim 1, wherein the ceramic material is tungsten carbide.

3. The method for preparing a cavitation and corrosion resistant metal-ceramic matrix composite according to claim 1, wherein the composite preform obtained in step (1) is subjected to a laser remelting treatment after being subjected to a pretreatment, wherein the pretreatment comprises at least one of a sand blasting roughening treatment, a rust removal treatment and an oil stain removal treatment.

4. The method for preparing a cavitation and corrosion resistant metal-ceramic matrix composite according to claim 3, wherein the process parameters of the sand blasting roughening treatment are as follows: the air pressure is 0.3-1.0 MPa, the sand blasting time is 10 s-2 min, and the grain diameter of sand for sand blasting is 40-200 meshes.

5. The method for preparing a cavitation and corrosion resistant ceramic matrix composite according to claim 1, wherein the laser remelting treatment parameters are: the power is 200-3000W; the diameter of the light spot is 0.3-3 mm; the moving speed of the light spot is 100-500 mm/min; the protective gas is high-purity nitrogen or argon; the pressure of the protective gas is 0.4-1.5 MPa; the flow rate is 4-8L/min.

6. The cavitation erosion and corrosion resistant metal-ceramic matrix composite prepared by the method for preparing the cavitation erosion and corrosion resistant metal-ceramic matrix composite according to any one of claims 1 to 5.

7. The cavitation erosion and corrosion resistant metal-ceramic matrix composite of claim 6, wherein the cavitation erosion and corrosion resistant metal-ceramic matrix composite has a cavitation erosion and corrosion resistant surface.

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