Anti-aging metal ceramic powder

Abstract

The invention relates to the technical field of ceramic powder, in particular to anti-aging metal ceramic powder which comprises, by weight, 60-80% of a hard material and 20-40% of a matrix metal composition, and the weight data is based on the total weight of the metal ceramic powder; the hard material is prepared from tungsten carbide, titanium carbide and tantalum carbide according to the mass ratio of (3-5): 2: 1; the matrix metal composition comprises an iron-cobalt-nickel alloy, chromium, molybdenum, copper, rare earth element lanthanum, nano silicon dioxide particles and a modifier, and the modifier is boron; according to the anti-aging metal ceramic powder provided by the invention, the composition proportion of the hard material to the matrix metal composition is optimized, and all the components have a synergistic effect, so that the basic performance of the metal ceramic powder is remarkably improved, and the comprehensive performance of a coating obtained by spraying the metal ceramic powder is also greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic powder, in particular to a kind of anti-aging cermet powder. BACKGROUND

[0002] Cermet powder is a kind of high-performance material composed of hard ceramic phase and metal matrix, which has high hardness, high temperature resistance of ceramic and toughness, processability of metal, and has wide application in thermal spraying coating field, such as aerospace engine parts protection, mechanical wear-resistant coating, chemical corrosion-resistant surface layer, etc. Through spraying process, cermet powder can form dense coating on the surface of substrate, which can significantly improve the service life of workpiece.

[0003] However, the coating prepared by the cermet powder in the prior art generally has the following defects:

[0004] Insufficient high-temperature stability: the metal matrix is not treated by traditional process, which leads to oxidation corrosion of the coating in high-temperature environment.

[0005] Weak interface bonding force: poor compatibility of hard phase and metal matrix.

[0006] Low density and mechanical properties: liquid phase sintering is insufficient during sintering process, and grain growth phenomenon is significant, which leads to insufficient hardness and wear resistance of the coating.

[0007] Poor corrosion resistance: corrosion medium can easily penetrate into the interior of the coating.

[0008] The present application improves the performance of the prior art through further improvement. SUMMARY

[0009] In view of the problems existing in the prior art, the present application provides an anti-aging cermet powder.

[0010] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0011] An anti-aging cermet powder, comprising 60-80 wt% of hard material and 20-40 wt% of matrix metal composition, the weight data being based on the total weight of the cermet powder; the hard material is made of tungsten carbide, titanium carbide, and tantalum carbide in a mass ratio of 3-5:2:1; the matrix metal composition comprises iron-cobalt-nickel alloy, chromium, molybdenum, copper, rare earth element lanthanum, nano-silicon dioxide particles and modifier, wherein the modifier is boron.

[0012] As a further technical scheme, the average particle size of the tungsten carbide, titanium carbide and tantalum carbide is 1-1.6 microns.

[0013] As a further technical solution, in the matrix metal composition, the iron-cobalt-nickel alloy accounts for 70-74% of the total weight of the matrix metal composition, and the weight ratio of iron, cobalt and nickel is 2-3:1:1; the iron-cobalt-nickel alloy is subjected to surface nitriding treatment to form a nitriding layer with a thickness of 0.1-0.3 microns on the surface of the alloy, and the nitriding treatment is carried out by plasma enhanced chemical vapor deposition method, the temperature of the nitriding treatment is 640-800℃, and the time is 2-4 hours.

[0014] As a further technical solution, in the matrix metal composition, molybdenum accounts for 12-16% of the total weight of the matrix metal composition, the molybdenum element forms a solid solution with the copper element, and the lattice distortion rate of the solid solution is 0.8-1.2%, by controlling the lattice distortion rate to enhance the stability of the cermet powder at high temperature, the temperature for forming the solid solution is 900-1100℃, and the holding time is 2-3 hours.

[0015] As a further technical solution, in the matrix metal composition, copper accounts for 6-9% of the total weight of the matrix metal composition, and the copper element is attached to a graphene coating layer with a thickness of 12-15 nanometers on the surface, the graphene coating layer is prepared by chemical vapor deposition method to improve the interface bonding force between copper and other metals, the temperature for preparing the graphene coating layer by chemical vapor deposition method is 870-1000℃, and the reaction time is 40-60 minutes.

[0016] As a further technical solution, in the matrix metal composition, the rare earth element lanthanum accounts for 3-4% of the total weight of the matrix metal composition, the rare earth element lanthanum exists in the form of lanthanum-oxygen-metal complex phase in the matrix metal, and the grain size of the lanthanum-oxygen-metal complex phase is less than 50 nanometers, effectively inhibiting grain growth, the temperature for forming the lanthanum-oxygen-metal complex phase is 1000-1200℃, and the time is 1-2 hours.

[0017] As a further technical solution, in the matrix metal composition, nano-silicon dioxide particles account for 1.8-2.5% of the total weight of the matrix metal composition, the surface of the nano-silicon dioxide particles is loaded with a nano-scale titanium dioxide coating with a thickness of 5-20 nanometers; the average particle size of the nano-silicon dioxide particles is 20-50 nanometers, the temperature for loading the nano-scale titanium dioxide coating is 580-700℃, and the time is 1-2 hours.

[0018] As a further technical solution, in the matrix metal composition, the modified agent boron accounts for 1.1-1.5% of the total weight of the matrix metal composition, the boron element forms a low-melting eutectic phase with the iron-cobalt-nickel alloy to promote liquid-phase sintering during sintering; the melting point of the low-melting eutectic phase is 1070-1150 DEG C, the powder density is improved by controlling the melting point of the eutectic phase, the temperature for forming the low-melting eutectic phase is 1000-1120 DEG C, and the time is 0.5-1 hour.

[0019] As a further technical solution, in the matrix metal composition, the balance is chromium element; the chromium element is uniformly dispersed in the matrix metal in the form of nanosheet, the average sheet diameter of the nanosheet chromium is 150-200 nanometers, the temperature for forming the nanosheet chromium is 800-1000 DEG C, and the time is 1-2 hours.

[0020] As a further technical solution, the cermet powder is obtained by ball milling the components under an argon protective atmosphere, the argon flow is 6-8 L / min, the ball milling speed is 350-400 r / min, the ball milling time is 8-12 hours, then vacuum sintering at 1200-1300 DEG C for 2-3 hours, and then powdering by the gas mist method and sorting to a particle size range of 10-70 mu m.

[0021] Compared with the prior art, the beneficial effects of the present application are:

[0022] The aging-resistant cermet powder provided by the present application significantly improves the basic performance of the cermet powder by optimizing the component ratio of the hard material and the matrix metal composition, and the comprehensive performance of the coating obtained by spraying is also greatly improved.

[0023] In the technical solution of the present application, the hard material composed of tungsten carbide, titanium carbide and tantalum carbide forms a gradient hardness structure: tungsten carbide provides high wear resistance, titanium carbide reduces density and improves thermal shock resistance, and tantalum carbide inhibits grain growth. The synergistic effect of the three greatly improves the microhardness of the sprayed coating, reduces the wear amount, and enhances the basic wear resistance of the coating.

[0024] In the technical solution of the present application, the surface nitriding treatment of the iron-cobalt-nickel alloy: a nitriding layer is formed on the alloy surface by plasma-enhanced chemical vapor deposition, which blocks the oxygen diffusion path, so that the weight gain rate of the coating in an 800 DEG C high-temperature oxidation environment is significantly reduced; at the same time, the nitriding layer forms a chemical bond with the ceramic phase, and the bonding strength of the coating is significantly improved, solving the problem of weak interfacial bonding force in traditional processes.

[0025] Interface optimization of copper surface graphene coating: the nano-graphene coating prepared by chemical vapor deposition enhances the interface bonding force between copper and iron-cobalt-nickel alloy throughπ-πconjugation, so that the coating strength is improved, the bonding strength stability is significantly improved, and the problem of coating peeling caused by interface debonding is avoided.

[0026] Complex phase regulation of rare earth element lanthanum: the rare earth element lanthanum exists in the form of lanthanum-oxygen-metal complex phase in the matrix metal, and the grain coarsening during high-temperature sintering is inhibited by pinning the grain boundary, and at the same time, the rare earth element adsorbs corrosive ions, so that the corrosion area of the coating is reduced in the salt spray corrosion test, and the corrosion resistance is significantly improved.

[0027] Liquid phase sintering promotion effect of boron and iron-cobalt-nickel alloy: the low melting point eutectic phase formed by boron element fills the pores during sintering, so that the relative density of the coating is improved, and at the same time, the liquid phase promotes the uniform dispersion of the hard phase, reduces the stress concentration, and further enhances the structural stability of the coating.

[0028] Composite protection effect of nano-silicon dioxide and titanium dioxide: the surface of nano-silicon dioxide particles is loaded with a nano-titanium dioxide coating, which enhances the dispersibility through electrostatic adsorption, forms a physical barrier to hinder the penetration of corrosive medium, and cooperates with the rare earth lanthanum complex phase to significantly improve the corrosion resistance of the coating compared with traditional processes.

[0029] Nanosheet structure strengthening of chromium element: the nanosheet chromium is uniformly dispersed to form a labyrinth effect, which prolongs the diffusion path of the corrosive medium, and at the same time, enhances the plastic deformation resistance of the coating, and cooperates with the lattice distortion regulation of the molybdenum-copper solid solution, to significantly improve the stability of the coating in high-temperature environment.

[0030] The technical scheme of the present application systematically solves the core defects of traditional metal ceramic coating, such as high-temperature oxidation, interface debonding, and insufficient wear resistance and corrosion resistance. It can be better applied to high-end equipment protection in the fields of aerospace, mechanical manufacturing, and chemical industry. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The test group wear amount statistical chart. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0033] The present application provides a kind of anti-aging cermet powder, comprising 60-80 wt% hard material and 20-40 wt% matrix metal composition, the weight data is based on the total weight of the cermet powder.The specific composition and process are as follows:

[0034] The hard material is made of tungsten carbide, titanium carbide, and tantalum carbide in a mass ratio of 3-5:2:1, and the average particle size of the three is 1-1.6 microns.

[0035] The matrix metal composition includes iron-cobalt-nickel alloy, chromium, molybdenum, copper, rare earth element lanthanum, nano-silicon dioxide particles, and modifier boron, each component has the following specific requirements:

[0036] Iron-cobalt-nickel alloy: 70-74 wt% of the total weight of the matrix metal composition, the weight ratio of iron, cobalt and nickel is 2-3:1:1.The alloy is surface-nitrided to form a nitrided layer with a thickness of 0.1-0.3 microns on the surface of the alloy, the nitriding treatment is carried out by plasma-enhanced chemical vapor deposition, the temperature is 640-800℃, and the time is 2-4 hours.

[0037] Molybdenum: 12-16 wt% of the total weight of the matrix metal composition, the molybdenum element forms a solid solution with the copper element, the lattice distortion rate of the solid solution is 0.8-1.2%, the stability of the cermet powder at high temperature is enhanced by controlling the lattice distortion rate, the temperature for forming the solid solution is 900-1100℃, and the holding time is 2-3 hours.

[0038] The specific method for forming a solid solution of molybdenum and copper elements is as follows: place molybdenum and copper in a vacuum furnace in the right proportion, heat to 900-1100℃ at a rate of 5℃ / min under nitrogen gas protection, hold for 2-3 hours, then cool to room temperature at a rate of 10℃ / min, and form a solid solution with a lattice distortion rate of 0.8-1.2% by atomic diffusion.

[0039] Copper: 6-9 wt% of the total weight of the matrix metal composition, the copper element has a graphene coating with a thickness of 12-15 nanometers on its surface, the graphene coating is prepared by chemical vapor deposition to improve the interfacial bonding force between copper and other metals, the temperature for preparing the graphene coating by chemical vapor deposition is 870-1000℃, and the reaction time is 40-60 minutes.

[0040] The graphene coating attached to the surface of the copper element is prepared by the following method: the copper is placed in a chemical vapor deposition reaction furnace, mixed gas of hydrogen and argon (volume ratio of hydrogen to argon is 1:3) is introduced, the copper surface is pretreated at 600℃ for 10 minutes to remove impurities on the surface of the copper; then, methane is used as carbon source, hydrogen and argon are used as carrier gas (volume ratio of methane, hydrogen and argon is 1:2:5), the reaction is carried out at 870-1000℃ for 40-60 minutes, so that carbon atoms produced by decomposition of methane are deposited and grown on the surface of the copper to form a graphene coating.

[0041] The rare earth element lanthanum accounts for 3-4% of the total weight of the substrate metal composition, the rare earth element lanthanum exists in the substrate metal in the form of a lanthanum-oxygen-metal complex phase, and the grain size of the lanthanum-oxygen-metal complex phase is less than 50 nanometers, effectively inhibiting grain growth, the temperature for forming the lanthanum-oxygen-metal complex phase is 1000-1200℃, and the time is 1-2 hours.

[0042] The specific formation method of the rare earth element lanthanum existing in the substrate metal in the form of a lanthanum-oxygen-metal complex phase is as follows: during the melting process of the substrate metal, the lanthanum element is added to the metal system in a liquid state, and oxygen is introduced at the same time (oxygen flow is 5L / min), and the mixture is stirred at 1000-1200℃ for 1-2 hours, so that the lanthanum, oxygen and metal are fully reacted by controlling the reaction conditions to form a lanthanum-oxygen-metal complex phase with a grain size of less than 50 nanometers.

[0043] The nano-silicon dioxide particles account for 1.8-2.5% of the total weight of the substrate metal composition, and the surface of the nano-silicon dioxide particles is loaded with a nanoscale titanium dioxide coating with a thickness of 5-20 nanometers; the average particle size of the nano-silicon dioxide particles is 20-50 nanometers, and the temperature for loading the nanoscale titanium dioxide coating is 580-700℃, and the time is 1-2 hours.

[0044] The specific method for loading the nanoscale titanium dioxide coating on the surface of the nano-silicon dioxide particles is as follows: the nano-silicon dioxide particles are dispersed in anhydrous ethanol by using a sol-gel method, and ultrasonic dispersion is performed for 30 minutes to form a uniform suspension with a mass fraction of 8%; then, tetrabutyl titanate is slowly added dropwise into a mixed solution containing ethanol, water and glacial acetic acid (volume ratio of ethanol, water and glacial acetic acid is 10:1:1), and stirring is performed for 30 minutes to form a titanium dioxide sol; the nano-silicon dioxide suspension is added to the titanium dioxide sol, and stirring is continued for 2 hours to enable the silicon dioxide particles to adsorb tetrabutyl titanate in the sol on their surfaces; then, heat treatment is performed at 580-700℃ for 1-2 hours to enable tetrabutyl titanate to hydrolyze and condense to form a nanoscale titanium dioxide coating.

[0045] The modifier boron: 1.1-1.5 wt% of the total weight of the substrate metal composition, the boron element forms a low melting point eutectic phase with the iron-cobalt-nickel alloy, which promotes liquid phase sintering during sintering; the melting point of the low melting point eutectic phase is 1070-1150℃, the powder density is improved by controlling the melting point of the eutectic phase, the temperature for forming the low melting point eutectic phase is 1000-1120℃, and the time is 0.5-1 hour.

[0046] Chromium element: the balance is chromium element, the chromium element is uniformly dispersed in the substrate metal in the form of nanosheet, the average sheet diameter of the nanosheet chromium is 150-200 nanometers, the temperature for forming the nanosheet chromium is 800-1000℃, and the time is 1-2 hours.

[0047] Preparation method:

[0048] The components are ball milled under an argon protective atmosphere (argon flow rate is 6-8 L / min), the ball milling speed is 350-400 r / min, the ball milling time is 8-12 hours, then vacuum sintering at 1200-1300℃ for 2-3 hours, then powdering by the gas mist method, and sorting to a particle size range of 10-70 microns to obtain the cermet powder. 0.3-0.8% of a dispersant polyvinylpyrrolidone based on the total weight of the material is added during ball milling, and the average molecular weight of the dispersant is 40000-50000.

[0049] The present application significantly improves the high-temperature aging resistance, interface bonding strength and density of the cermet powder by optimizing the composition and ratio of the hard phase and the substrate metal, combining surface modification and composite phase regulation technology, and solves the problems of easy oxidation and performance degradation caused by grain growth of traditional cermet in high temperature environment.

[0050] The raw materials used in the following examples are all commercially available conventional products, wherein:

[0051] Tungsten carbide, titanium carbide, and tantalum carbide: average particle size 1.2 microns, purity ≥99.5%.

[0052] Iron-cobalt-nickel alloy: prepared in proportion, the weight ratio of iron, cobalt and nickel is the proportion in the corresponding example.

[0053] Molybdenum, copper, rare earth element lanthanum, nanosilica particles, boron, chromium, etc.: the purity meets the industrial standard.

[0054] Dispersant polyvinylpyrrolidone: average molecular weight 45000.

[0055] Example 1

[0056] Composition and ratio (based on the total weight of the cermet powder):

[0057] Hard material: 70 wt%, wherein tungsten carbide: titanium carbide: tantalum carbide is 4:2:1.

[0058] Matrix metal composition: 30 wt%, wherein iron cobalt nickel alloy (iron: cobalt: nickel is 2.5:1:1) is 71 wt%, molybdenum 14 wt%, copper 7.5 wt%, rare earth element lanthanum 3.5 wt%, nano-silica particles 2.2 wt%, boron 1.3 wt%, chromium balance.

[0059] Iron cobalt nickel alloy nitriding treatment: temperature 720°C, time 3 hours, nitrided layer thickness 0.2 microns.

[0060] Molybdenum copper solid solution formation: temperature 1000°C, holding time 2.5 hours, lattice distortion rate 1.0%.

[0061] Copper surface graphene coating preparation: temperature 930°C, reaction time 50 minutes, coating thickness 13 nanometers.

[0062] Lanthanum-oxygen-metal complex phase formation: temperature 1100°C, time 1.5 hours, grain size <50 nanometers.

[0063] Nano-silica loaded titanium dioxide coating: temperature 640°C, time 1.5 hours, coating thickness 12 nanometers.

[0064] Boron and iron cobalt nickel alloy form eutectic phase: temperature 1060°C, time 0.8 hours, eutectic phase melting point 1110°C.

[0065] Chromium nanoplate formation: temperature 900°C, time 1.5 hours, average plate diameter 175 nanometers.

[0066] Preparation process: the components are weighed according to the ratio, ball milled at 375 r / min for 10 hours under the condition of argon flow 7 L / min (0.5% dispersant is added), then vacuum sintered at 1250°C for 2.5 hours, finally powdered by gas mist method and sorted to 10-70 μm.

[0067] Example 2

[0068] Component ratio (based on total weight of cermet powder):

[0069] Hard material: 65 wt%, wherein tungsten carbide: titanium carbide: tantalum carbide is 3:2:1.

[0070] Matrix metal composition: 35 wt%, wherein iron cobalt nickel alloy (iron: cobalt: nickel is 2:1:1) is 71 wt%, molybdenum 16 wt%, copper 6 wt%, rare earth element lanthanum 3 wt%, nano-silica particles 2.5 wt%, boron 1.1 wt%, chromium balance.

[0071] Iron-cobalt-nickel alloy nitriding: temperature 640°C, time 4 hours, nitrided layer thickness 0.1 microns.

[0072] Molybdenum-copper solid solution formation: temperature 900°C, holding time 3 hours, lattice distortion rate 0.8%.

[0073] Copper surface graphene coating preparation: temperature 870°C, reaction time 60 minutes, coating thickness 15 nanometers.

[0074] Lanthanum-oxygen-metal complex phase formation: temperature 1000°C, time 2 hours, grain size < 50 nanometers.

[0075] Nano-silicon dioxide supported titanium dioxide coating: temperature 580°C, time 2 hours, coating thickness 20 nanometers.

[0076] Boron eutectic phase formation with iron-cobalt-nickel alloy: temperature 1000°C, time 1 hour, eutectic phase melting point 1070°C.

[0077] Chromium nanoplate formation: temperature 800°C, time 2 hours, average plate diameter 150 nanometers.

[0078] Preparation process: ingredients are weighed according to the ratio, ball-milled at 350 r / min for 12 hours under an argon flow of 6 L / min (0.3% dispersant is added), then vacuum sintered at 1200°C for 3 hours, and finally powdered by the gas mist method and sorted to 10-70 microns.

[0079] Example 3

[0080] Ingredient ratio (based on the total weight of the cermet powder):

[0081] Hard material: 75% by weight, of which tungsten carbide: titanium carbide: tantalum carbide is 5:2:1.

[0082] Matrix metal composition: 25% by weight, of which iron-cobalt-nickel alloy (iron: cobalt: nickel is 3:1:1) accounts for 71% by weight, molybdenum 12% by weight, copper 9% by weight, rare earth element lanthanum 4% by weight, nano-silicon dioxide particles 1.8% by weight, boron 1.5% by weight, and chromium the balance.

[0083] Iron-cobalt-nickel alloy nitriding: temperature 800°C, time 2 hours, nitrided layer thickness 0.3 microns.

[0084] Molybdenum-copper solid solution formation: temperature 1100°C, holding time 2 hours, lattice distortion rate 1.2%.

[0085] Copper surface graphene coating preparation: temperature 1000°C, reaction time 40 minutes, coating thickness 12 nanometers.

[0086] Lanthanum-oxygen-metal complex phase formation: temperature 1200°C, time 1 hour, grain size < 50 nm.

[0087] Nano-silica supported titanium dioxide coating: temperature 700°C, time 1 hour, coating thickness 5 nm.

[0088] Boron eutectic phase formation with iron-cobalt-nickel alloy: temperature 1120°C, time 0.5 hour, eutectic phase melting point 1150°C.

[0089] Chromium nanoplatelet formation: temperature 1000°C, time 1 hour, average platelet diameter 200 nm.

[0090] Preparation process: the components are weighed according to the proportions, ball-milled at 400 rpm for 8 hours under an argon flow of 8 L / min (0.8% of dispersant is added), then sintered in vacuum at 1300°C for 2 hours, and finally powdered by the gas atomization method and sorted to 10-70 pm.

[0091] Example 4

[0092] Proportions of the components (based on the total weight of the cermet powder):

[0093] Hard material: 60% by weight, of which tungsten carbide: titanium carbide: tantalum carbide is 3.5:2:1.

[0094] Matrix metal composition: 40% by weight, of which iron-cobalt-nickel alloy (iron: cobalt: nickel is 2.8:1:1) is 72% by weight, molybdenum is 13% by weight, copper is 8% by weight, rare earth element lanthanum is 3.2% by weight, nano-silica particles are 2.0% by weight, boron is 1.2% by weight, and chromium is the balance.

[0095] Iron-cobalt-nickel alloy nitriding treatment: temperature 750°C, time 2.5 hours, nitriding layer thickness 0.2 pm.

[0096] Molybdenum-copper solid solution formation: temperature 950°C, holding time 2.8 hours, lattice distortion rate 0.9%.

[0097] Copper surface graphene coating preparation: temperature 900°C, reaction time 55 minutes, coating thickness 14 nm.

[0098] Lanthanum-oxygen-metal complex phase formation: temperature 1050°C, time 1.8 hours, grain size < 50 nm.

[0099] Nano-silica supported titanium dioxide coating: temperature 600°C, time 1.2 hours, coating thickness 8 nm.

[0100] Boron eutectic phase formation with iron-cobalt-nickel alloy: temperature 1080°C, time 0.7 hour, eutectic phase melting point 1130°C.

[0101] Chromium nanosheet formation: temperature 850°C, time 1.8 hours, average sheet diameter 160 nanometers.

[0102] Preparation procedure: The components were weighed out in the proportions stated, ball milled for 9 hours at 380 rpm (0.6% dispersant added) under an argon flow of 7 L / min, then vacuum sintered at 1280°C for 2.2 hours, and finally powdered by the gas atomisation method and sorted to 10-70 μm.

[0103] Example 5

[0104] Proportions of ingredients (based on the total weight of the cermet powder):

[0105] Hard material: 80% by weight, of which tungsten carbide: titanium carbide: tantalum carbide is 4.5:2:1.

[0106] Matrix metal composition: 20% by weight, of which an iron-cobalt-nickel alloy (iron: cobalt: nickel is 3:1:1) is 70% by weight, molybdenum 15% by weight, copper 7% by weight, the rare earth element lanthanum 3.8% by weight, nano-silicon dioxide particles 2.3% by weight, boron 1.4% by weight, and the balance chromium.

[0107] Iron-cobalt-nickel alloy nitriding treatment: temperature 780°C, time 2.2 hours, nitrided layer thickness 0.25 microns.

[0108] Molybdenum-copper solid solution formation: temperature 1050°C, holding time 2.3 hours, lattice distortion rate 1.1%.

[0109] Copper surface graphene coating preparation: temperature 980°C, reaction time 45 minutes, coating thickness 13 nanometers.

[0110] Lanthanum-oxygen-metal complex phase formation: temperature 1150°C, time 1.2 hours, grain size <50 nanometers.

[0111] Nano-silicon dioxide supported titanium dioxide coating: temperature 680°C, time 1.3 hours, coating thickness 18 nanometers.

[0112] Boron and iron-cobalt-nickel alloy eutectic phase formation: temperature 1100°C, time 0.6 hours, eutectic phase melting point 1140°C.

[0113] Chromium nanosheet formation: temperature 950°C, time 1.3 hours, average sheet diameter 190 nanometers.

[0114] Preparation procedure: The components were weighed out in the proportions stated, ball milled for 8.5 hours at 390 rpm (0.7% dispersant added) under an argon flow of 7.5 L / min, then vacuum sintered at 1220°C for 2.8 hours, and finally powdered by the gas atomisation method and sorted to 10-70 μm.

[0115] Comparative Example 1

[0116] Composition ratio (based on total weight of cermet powder):

[0117] Hard material: 70wt%, wherein tungsten carbide: titanium carbide: tantalum carbide is 4:2:1.

[0118] Matrix metal composition: 30wt%, wherein iron-cobalt-nickel alloy (not nitrided) accounts for 70wt%, molybdenum 14wt%, copper 7.5wt%, rare earth element lanthanum 3.5wt%, nano-silicon dioxide particles 2.2wt%, and the balance of chromium.

[0119] Preparation process: the remaining process parameters are the same as example 1, except that the iron-cobalt-nickel alloy is not nitrided.

[0120] Comparative example 2

[0121] Composition ratio (based on total weight of cermet powder):

[0122] Hard material: 70wt%, wherein tungsten carbide: titanium carbide: tantalum carbide is 4:2:1.

[0123] Matrix metal composition: 30wt%, wherein iron-cobalt-nickel alloy (iron: cobalt: nickel is 2.5:1:1, nitrided) accounts for 70wt%, molybdenum 14wt%, copper (not coated with graphene) 7.5wt%, nano-silicon dioxide particles 2.2wt%, boron 1.3wt%, and the balance of chromium.

[0124] Preparation process: the remaining process parameters are the same as example 1, except that the copper is not coated with graphene.

[0125] High-temperature aging resistance performance test

[0126] Test method: according to GB / T13303-1991 "determination method of oxidation resistance of steel", the sample is kept at 800℃ in air atmosphere for 50 hours, and the oxidation weight gain rate (mg / cm 2 ·h) is measured.

[0127] Table 1

[0128]

[0129]

[0130] As can be seen from table 1, the cermet powder prepared by the present application has excellent aging resistance performance.

[0131] Example and comparative example powder is sprayed by supersonic flame spray gun with kerosene as fuel, under standard parameters (kerosene flow: 22.6L / h, oxygen flow: 56.6m 3Coating sample obtained by spraying (inlet pressure: 4.0MPa, powder feeding rate: 75g / min, spraying distance: 380mm) ;

[0132] Microhardness test of coating

[0133] Test method: refer to GB / T9790 "Metallic and other inorganic coatings - Vickers and Knoop microhardness test of coatings", using microhardness tester, loading load 50g, pressure maintaining 10s, measuring 5 points on the surface of the coating and taking average value.

[0134] Test results:

[0135] Table 2

[0136]

[0137]

[0138] As can be seen from Table 2, the coating prepared from the powder of the application has excellent surface hardness.

[0139] Abrasion resistance test of coating

[0140] Test method: refer to GB / T12444 "Metallic materials - Wear testing - Wear of plastics and rubbers by a rotating abrasive wheel", using dry sand rubber wheel abrasion method, abrasive is 120 mesh quartz sand, load 20N, grinding wheel speed 200r / min, testing coating weight loss (mg) ;

[0141] Table 3

[0142]

[0143]

[0144] As can be seen from Table 3, the coating prepared from the cermet powder of the application has excellent surface abrasion resistance.

[0145] Corrosion resistance test of coating

[0146] Test method: refer to GB / T10125 "Salt spray tests - Artificial atmospheric corrosion of metals", using 5% NaCl solution, temperature 35℃, continuous spraying for 240 hours, observing the percentage of corrosion area on the surface of the coating;

[0147] Table 4:

[0148]

[0149]

[0150] As can be seen from Table 4, the coating prepared from the cermet powder of the application has excellent corrosion resistance.

[0151] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all the details of the application, nor limit the application to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of the present specification.

Claims

1. An aging-resistant metal ceramic powder, characterized in that: The invention relates to a cermet powder comprising 60-80 wt% of a hard material and 20-40 wt% of a matrix metal composition, wherein the weight data is based on the total weight of the cermet powder; the hard material is made of tungsten carbide, titanium carbide, and tantalum carbide in a mass ratio of 3-5:2:1; and the matrix metal composition comprises an iron-cobalt-nickel alloy, chromium, molybdenum, copper, the rare earth element lanthanum, nano-silica particles, and a modifier, wherein the modifier is boron.

2. The aging-resistant metal ceramic powder according to claim 1, characterized in that: The average particle size of the tungsten carbide, titanium carbide and tantalum carbide is 1-1.6 microns.

3. The aging-resistant metal ceramic powder according to claim 1, characterized in that: In the matrix metal composition, the iron-cobalt-nickel alloy accounts for 70-74% by weight of the total weight of the matrix metal composition, and the weight ratio of iron, cobalt, and nickel is 2-3:1:

1. The iron-cobalt-nickel alloy is surface nitrided to form a nitride layer with a thickness of 0.1-0.3 microns on the alloy surface. The nitriding is performed using plasma-enhanced chemical vapor deposition at a temperature of 640-800° C. for 2-4 hours.

4. The aging-resistant metal ceramic powder according to claim 3, characterized in that: In the matrix metal composition, molybdenum accounts for 12-16 weight percent of the total weight of the matrix metal composition. The molybdenum element forms a solid solution with the copper element, and the lattice distortion rate of the solid solution is 0.8-1.2%. The temperature for forming the solid solution is 900-1100° C., and the holding time is 2-3 hours.

5. The aging-resistant metal ceramic powder according to claim 4, characterized in that: In the matrix metal composition, copper accounts for 6-9 weight percent of the total weight of the matrix metal composition. A graphene coating with a thickness of 12-15 nanometers is attached to the surface of the copper element. The graphene coating is prepared by chemical vapor deposition. The temperature for preparing the graphene coating by chemical vapor deposition is 870-1000° C., and the reaction time is 40-60 minutes.

6. The aging-resistant metal ceramic powder according to claim 5, characterized in that: In the matrix metal composition, the rare earth element lanthanum accounts for 3-4 weight percent of the total weight of the matrix metal composition. The rare earth element lanthanum is present in the matrix metal in the form of a lanthanum-oxygen-metal composite phase, and the grain size of the lanthanum-oxygen-metal composite phase is less than 50 nanometers. The temperature for forming the lanthanum-oxygen-metal composite phase is 1000-1200° C., and the time for forming the lanthanum-oxygen-metal composite phase is 1-2 hours.

7. The aging-resistant metal ceramic powder according to claim 6, characterized in that: In the matrix metal composition, the nano-silica particles account for 1.8-2.5% by weight of the total weight of the matrix metal composition; the surface of the nano-silica particles is loaded with a nano-scale titanium dioxide coating, and the coating thickness is 5-20 nanometers; the average particle size of the nano-silica particles is 20-50 nanometers, and the temperature for loading the nano-scale titanium dioxide coating is 580-700°C and the time is 1-2 hours.

8. The aging-resistant metal ceramic powder according to claim 7, characterized in that: In the matrix metal composition, the modifier boron accounts for 1.1-1.5% by weight of the total weight of the matrix metal composition, and the boron element forms a low-melting-point eutectic phase with the iron-cobalt-nickel alloy; the melting point of the low-melting-point eutectic phase is 1070-1150° C., the temperature for forming the low-melting-point eutectic phase is 1000-1120° C., and the time for forming the low-melting-point eutectic phase is 0.5-1 hour.

9. The aging-resistant metal ceramic powder according to claim 8, characterized in that: The balance of the matrix metal composition is chromium; the chromium is uniformly dispersed in the matrix metal in the form of nano-flakes, the average diameter of the nano-flake chromium is 150-200 nanometers, and the temperature for forming the nano-flake chromium is 800-1000° C. and the time is 1-2 hours.

10. The aging-resistant metal ceramic powder according to any one of claims 1 to 9, characterized in that: The metal ceramic powder is obtained by mixing the components by ball milling under an argon protective atmosphere at an argon flow rate of 6-8 L / min, at a ball milling speed of 350-400 r / min, for 8-12 hours, and then vacuum sintering at 1200-1300°C for 2-3 hours, and then powdering by an aerosol method and sorting to a particle size range of 10-70 μm. During the ball milling process, a dispersant polyvinyl pyrrolidone is added at a weight percentage of 0.3-0.8% of the total material weight, and the average molecular weight of the dispersant is 40,000-50,000.

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