A method for preparing rare earth modified spray powder and spray powder thereof

Abstract

The invention discloses a method for preparing a rare earth modified spray powder and the spray powder thereof. The method comprises the following steps: cold welding and extrusion of a base powder of a first shape having a first predetermined size and a rare earth powder of a second shape having a second predetermined size through mechanical ball milling to press the rare earth powder into the base powder, wherein the base powder comprises metal and its alloy, ceramic or organic polymer, the rare earth powder comprises single substance and compound of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and the first predetermined size is larger than the second predetermined size; the base powder pressed into the rare earth powder after mechanical ball milling is subjected to solid solution heat treatment to form a composite powder, so as to obtain the rare earth modified spray powder.

Description

Technical Field

[0001] The invention belongs to the technical field of material processing, in particular to a method for preparing rare earth modified spray powder and the spray powder. Background Art

[0002] During the thermal spraying and cold spraying processes, the spray powder is melted by heat sources such as flames, plasma, lasers, and accelerated by high-pressure airflow to prepare a coating. However, the spray powder particles inevitably decompose, evaporate, and oxidize during the heating and accelerated flight process. This causes the composition of the coating to deviate from the designed composition, the amount of oxides in the coating to increase, and the poor bonding between the particles in the coating, which seriously affects the performance of the coating. The coating's bonding strength, corrosion resistance, and wear resistance are only 1 / 3 of the same component block. Adding rare earth elements to the spray powder can effectively inhibit the decomposition, oxidation, and evaporation of the elements in the spray powder, but the rare earth elements themselves are easily oxidized and volatilized, which makes it difficult for the existing smelting and atomization methods to effectively add rare earth elements to the spray powder. How to effectively add rare earth elements to the spray powder to improve the performance of thermal spray and cold spray coatings is a problem that people in this technical field are currently working on.

[0003] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention proposes a method for preparing a rare earth-modified spray powder and the spray powder thereof, which effectively solves the problem of adding rare earth elements into the spray powder to improve the performance of thermal spray and cold spray coatings.

[0005] The purpose of the present invention is achieved by the following technical scheme. A method for preparing a rare earth modified spray powder comprises the following steps:

[0006] A base powder of a first shape having a first predetermined size and a rare earth powder of a second shape having a second predetermined size are cold welded by mechanical ball milling and pressed into the rare earth powder by extrusion, wherein the base powder includes metal and its alloy, ceramic or organic polymer;

[0007] The rare earth powder includes single substances and compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and the first predetermined size is greater than the second predetermined size;

[0008] The matrix powder into which the rare earth powder is pressed after mechanical ball milling is subjected to solid solution heat treatment to form a composite powder, thereby obtaining a rare earth modified spray powder.

[0009] In the method, the first predetermined size is 20-200 μm, and the second predetermined size is 0.1 nm-10 μm.

[0010] In the method, the first shape or the second shape includes a spherical shape, a polygonal shape and an irregular shape.

[0011] In the method described, the metal and alloys of the matrix powder include lithium, magnesium, aluminum, titanium, iron, copper, zinc, nickel, cobalt, lead, zinc, tin, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, molybdenum, chromium, manganese, gold, silver, platinum, ruthenium, rhodium, palladium, gallium, indium, thallium, calcium, strontium, barium and their alloys.

[0012] In the described method, the compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium include oxides, chlorides, fluorides, hydrides, nitrides, sulfides, halides, carbides or intermetallic compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

[0013] In the method, mechanical ball milling includes ball milling using a mixer, a planetary ball mill, a high-energy ball mill, a stirring ball mill or a vibrating ball mill.

[0014] In the method, the cold welding and extrusion effect of the mechanical ball mill is obtained under the conditions that the rotation speed of the mechanical ball mill is 0.1-2000r / min, the ball milling time is 0.1-2000 hours, and the ratio of the total powder of the grinding balls and the matrix powder to the rare earth powder is 0.1:1-200:1.

[0015] In the method, the solution heat treatment includes vacuum solution heat treatment, atmosphere protection solution heat treatment or solution heat treatment in a conventional atmospheric environment.

[0016] In the method, the temperature of the solution heat treatment is 100-3000° C., and the time of the solution heat treatment is 0.1-100 hours.

[0017] A spray powder is prepared by the method. In the spray powder, the size of the spray powder is 0.1-200 μm.

[0018] Beneficial Effects

[0019] The method for preparing the rare earth modified spray powder provided by the present invention is highly practical, and can effectively press the rare earth powder into the matrix powder through the cold welding and extrusion of mechanical ball milling, and then dissolve the rare earth element in the matrix powder through solid solution heat treatment to form a rare earth modified composite powder. The rare earth element does not decompose during the preparation process, which effectively avoids the problem that the rare earth element is easy to volatilize and decompose during the preparation of the rare earth modified spray powder by the traditional melting and atomization method, resulting in deviations in the rare earth additive components and difficulty in adding. The present invention provides an effective solution for the preparation of rare earth modified spray powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] By reading the detailed description of the preferred specific embodiments below, various advantages and benefits of the present invention will become clear to those skilled in the art. The drawings in the specification are only used to illustrate the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In addition, the same reference numerals are used to represent the same components throughout the drawings.

[0021] In the attached picture:

[0022] Figure 1 This is the morphology of rare earth cerium (Ce) powder in a preferred embodiment of the present invention;

[0023] Figure 2 This is the morphology of the iron-based alloy powder modified by rare earth cerium (Ce) in a preferred embodiment of the present invention;

[0024] Figure 3 This is an energy spectrum diagram of rare earth cerium (Ce) added to the iron-based alloy powder of a preferred embodiment of the present invention;

[0025] Figure 4 The structure of the iron-based alloy coating modified by rare earth cerium (Ce) in a preferred embodiment of the present invention;

[0026] Figure 5 It is the hardness of an iron-based alloy coating and an iron-based alloy coating modified by rare earth cerium (Ce) according to a preferred embodiment of the present invention; wherein A is an iron-based alloy coating, and B is an iron-based alloy coating modified by rare earth cerium (Ce).

[0027] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0028] The following reference Figures 1 to 5The specific embodiments of the present invention will be described in more detail. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0029] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is still based on the general principles of the specification and is not used to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0030] To facilitate understanding of the embodiments of the present invention, further explanation will be given below by taking specific embodiments as examples in conjunction with the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0031] For better understanding, a method for preparing a rare earth modified spray powder comprises the following steps:

[0032] A base powder of a first shape having a first predetermined size and a rare earth powder of a second shape having a second predetermined size are cold welded by mechanical ball milling and pressed into the rare earth powder by extrusion, wherein the base powder includes metal and its alloy, ceramic or organic polymer;

[0033] The rare earth powder includes single substances and compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and the first predetermined size is greater than the second predetermined size;

[0034] The matrix powder into which the rare earth powder is pressed after mechanical ball milling is subjected to solid solution heat treatment to form a composite powder, thereby obtaining a rare earth modified spray powder.

[0035] In a preferred embodiment of the method, the first predetermined size is 20-200 μm, and the second predetermined size is 0.1 nm-10 μm.

[0036] In a preferred embodiment of the method, the first shape or the second shape includes a spherical shape, a polygonal shape and an irregular shape.

[0037] In a preferred embodiment of the method, the metal and alloys of the matrix powder include lithium, magnesium, aluminum, titanium, iron, copper, zinc, nickel, cobalt, lead, zinc, tin, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, molybdenum, chromium, manganese, gold, silver, platinum, ruthenium, rhodium, palladium, gallium, indium, thallium, calcium, strontium, barium and their alloys.

[0038] In a preferred embodiment of the method, the compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium include oxides, chlorides, fluorides, hydrides, nitrides, sulfides, halides, carbides or intermetallic compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

[0039] In a preferred embodiment of the method, the mechanical ball milling includes ball milling using a mixer, a planetary ball mill, a high-energy ball mill, a stirring ball mill or a vibrating ball mill.

[0040] In a preferred embodiment of the method, the cold welding and extrusion effect of the mechanical ball mill is obtained under the conditions that the rotation speed of the mechanical ball mill is 0.1-2000r / min, the ball milling time is 0.1-2000 hours, and the ratio of the total powder of the grinding balls and the matrix powder to the rare earth powder is 0.1:1-200:1.

[0041] In a preferred embodiment of the method, the solution heat treatment includes vacuum solution heat treatment, atmosphere protection solution heat treatment or solution heat treatment in a conventional atmospheric environment.

[0042] In a preferred embodiment of the method, the temperature of the solution heat treatment is 100-3000° C., and the time of the solution heat treatment is 0.1-100 hours.

[0043] In a preferred embodiment of the method, the spray powder has a size of 0.1-200 μm.

[0044] In one embodiment, the method includes that the rare earth modified spray powder is prepared by mechanical ball milling; the matrix of the spray powder is metal and its alloy, ceramic or organic polymer; the rare earth elements include cerium (Ce), lanthanum (La), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and their compounds; the rare earth elements are pressed into the matrix powder by cold welding and extrusion of mechanical ball milling, and then the rare earth elements are dissolved in the matrix powder by solution heat treatment to form a composite powder. The mechanical ball milling includes: mechanical ball milling of equipment such as mixer, planetary ball mill, high energy ball mill, stirring ball mill, vibration ball mill, etc.

[0045] Furthermore, the rare earth powder is a powder in a spherical, polygonal, irregular or other shape, and has a size of 0.1 nm-10 μm.

[0046] Furthermore, the spraying powder is a powder in a spherical, polygonal, irregular or other shape, and has a size of 0.1-200 μm.

[0047] Furthermore, the rotation speed of the mechanical ball mill is 0.1-2000 r / min, the ball milling time is 0.1-2000 hours, and the ratio of grinding balls to powder is 0.1:1-200:1.

[0048] Furthermore, the rare earth elements include single substances, oxides, chlorides, fluorides, hydrides, nitrides, sulfides, halides, carbides or intermetallic compounds of cerium (Ce), lanthanum (La), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu).

[0049] Furthermore, the rare earth element is pressed into the matrix powder by cold welding and extrusion of mechanical ball milling.

[0050] Furthermore, the solution heat treatment dissolves the rare earth element in the matrix powder to form a composite powder.

[0051] Furthermore, the solution heat treatment includes vacuum solution heat treatment, atmosphere protection solution heat treatment or solution heat treatment in a conventional atmospheric environment.

[0052] Furthermore, the temperature of the solution heat treatment is 100-3000° C., and the time of the solution heat treatment is 0.1-100 hours.

[0053] Furthermore, the spraying powder has a size of 0.1-200 μm.

[0054] Furthermore, in the coating prepared by the rare earth modified spray powder, the rare earth element can effectively purify impurities in the coating, inhibit the oxidation and decomposition of the substrate, and be dissolved in the coating. The impurity and oxygen content in the coating is greatly reduced, and the hardness, bonding strength, anti-oxidation, corrosion resistance, wear resistance, optics, electricity, magnetism, biology and other properties of the coating are significantly improved.

[0055] Example 1

[0056] Use Figure 1The polygonal rare earth cerium (Ce) powder with a size of 0.1-5 μm and the spherical iron-based alloy powder with a size of 50-100 μm were ball-milled in a planetary ball mill. The speed of the mechanical ball milling was 200 r / min, the ball milling time was 10 hours, and the ratio of the grinding ball to the powder was 20:1. Then, the solution heat treatment was carried out under vacuum and 800°C for 1 hour. The obtained rare earth cerium (Ce) modified iron-based alloy powder is as shown in FIG. Figure 2 shown. Figure 3 The energy spectrum of rare earth cerium (Ce) added to iron-based alloy powder. The microstructure of the iron-based alloy coating modified with rare earth cerium (Ce) prepared by plasma spraying is shown in Figure 2. Figure 4 As shown in Figure 1, rare earth cerium (Ce) has been completely dissolved in the iron-based alloy coating. Figure 5 As shown, the hardness of the conventional iron-based alloy coating is 214HV 100gf The hardness of the iron-based alloy coating modified by rare earth cerium (Ce) is 645HV 100gf , which is three times the hardness of the iron-based alloy coating without adding rare earth.

[0057] Example 2

[0058] Spherical rare earth lanthanum (La) powder with a size of 0.1-10 μm and polygonal copper-based alloy powder with a size of 10-50 μm are used for ball milling in a mixer. The ball milling speed is 300r / min, the ball milling time is 20 hours, and the ratio of grinding balls to powder is 30:1. Subsequently, solid solution heat treatment is carried out for 2 hours under vacuum and 600°C. Copper-based alloy powder modified with rare earth lanthanum (La) is prepared. A copper-based alloy coating modified with rare earth lanthanum (La) is prepared by oxyacetylene flame spraying. Rare earth lanthanum (La) is completely dissolved in the copper-based alloy coating, and its wear resistance is twice that of the copper-based alloy coating without adding rare earth lanthanum (La).

[0059] Example 3

[0060] Irregular rare earth praseodymium (Pr) powder with a size of 0.1-5μm and irregular nickel-based alloy powder with a size of 15-100μm are used for ball milling in a high-energy ball mill. The ball milling speed is 500r / min, the ball milling time is 30 hours, and the ratio of grinding balls to powder is 15:1. Subsequently, solid solution heat treatment is carried out under vacuum and 1000℃ for 5 hours. A nickel-based alloy powder modified with rare earth praseodymium (Pr) is prepared. A nickel-based alloy coating modified with rare earth praseodymium (Pr) is prepared by laser cladding spraying. Rare earth praseodymium (Pr) is completely dissolved in the nickel-based alloy coating, and its corrosion resistance is twice that of the nickel-based alloy coating without rare earth praseodymium (Pr).

[0061] Example 4

[0062] Polygonal rare earth ytterbium (Yb) powder with a size of 0.1nm-2μm and irregular zirconium oxide powder with a size of 20-150μm were used for ball milling in a stirred ball mill. The ball milling speed was 300r / min, the ball milling time was 50 hours, and the ratio of grinding balls to powder was 20:1. Subsequently, solid solution heat treatment was carried out under vacuum and 1100℃ for 6 hours. Rare earth ytterbium (Yb) modified zirconium oxide powder was prepared. Rare earth ytterbium (Yb) modified zirconium oxide coating was prepared by supersonic flame spraying. Rare earth ytterbium (Yb) was completely dissolved in the zirconium oxide coating, and its antioxidant performance was 3 times that of the zirconium oxide coating without rare earth ytterbium (Yb).

[0063] Example 5

[0064] Irregular rare earth dysprosium oxide (Dy2O3) powder with a size of 0.2nm-5μm and irregular polyester-epoxy resin powder with a size of 30-100μm are used for ball milling in a vibrating ball mill. The ball milling speed is 600r / min, the ball milling time is 100 hours, and the ratio of grinding balls to powder is 30:1. Subsequently, solid solution heat treatment is carried out under vacuum and 300℃ for 20 hours. Rare earth dysprosium oxide (Dy2O3) modified polyester-epoxy resin powder is prepared. Rare earth dysprosium oxide (Dy2O3) modified polyester-epoxy resin coating is prepared by flame spraying. Rare earth dysprosium oxide (Dy2O3) is completely dissolved in the polyester-epoxy resin coating, and its anti-shielding performance is 3 times that of the polyester-epoxy resin coating without adding rare earth dysprosium oxide (Dy2O3).

[0065] Example 6

[0066] Spherical rare earth gadolinium oxide (Gd2O3) powder with a size of 0.3nm-3μm and spherical nylon powder with a size of 20-150μm are used for ball milling in a high-energy ball mill. The ball milling speed is 800r / min, the ball milling time is 150 hours, and the ratio of grinding balls to powder is 40:1. Subsequently, solid solution heat treatment is carried out for 30 hours under vacuum and 300℃. Nylon powder modified with rare earth gadolinium oxide (Gd2O3) is prepared. Nylon coating modified with rare earth gadolinium oxide (Gd2O3) is prepared by flame spraying. Rare earth gadolinium oxide (Gd2O3) is completely dissolved in the nylon coating, and its corrosion resistance is twice that of nylon coating without rare earth gadolinium oxide (Gd2O3).

[0067] A spray powder is prepared by the method. The size of the spray powder is 0.1-200 μm. The spray coating is prepared by using the rare earth modified spray powder, and the rare earth element can effectively purify impurities in the coating, inhibit the oxidation and decomposition of the substrate, and be dissolved in the spray powder. The impurity and oxygen content in the spray powder are greatly reduced, and the hardness, oxidation resistance, corrosion resistance, wear resistance and other properties of the coating are significantly improved.

[0068] Although the embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields, and the above specific embodiments are only illustrative and instructive, rather than restrictive. A person of ordinary skill in the art can also make many forms under the guidance of this specification and without departing from the scope of protection of the claims of the present invention, all of which belong to the protection of the present invention.

Claims

1. A method for preparing a rare earth modified spray powder, characterized in that: The method comprises the following steps: A base powder of a first shape having a first predetermined size and a rare earth powder of a second shape having a second predetermined size are cold welded by mechanical ball milling and pressed into the rare earth powder by extrusion, wherein the base powder includes metal and its alloy, ceramic or organic polymer; The rare earth powder includes single substances and compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and the first predetermined size is greater than the second predetermined size; The matrix powder pressed into the rare earth powder after mechanical ball milling is subjected to solid solution heat treatment to form a composite powder to obtain a rare earth modified spray powder, the first predetermined size is 20-200µm, the second predetermined size is 0.1nm-10µm, the cold welding and extrusion effect of the mechanical ball milling is obtained under the conditions that the speed of the mechanical ball mill is 0.1-2000r / min, the ball milling time is 0.1-2000 hours, the ratio of the total powder of the grinding balls and the matrix powder to the rare earth powder is 0.1:1-200:1, and the rare earth element does not decompose during the preparation process.

2. The method according to claim 1, characterized in that The first shape or the second shape includes a spherical shape, a polygonal shape, and an irregular shape.

3. The method according to claim 1, characterized in that The metals and alloys of the matrix powder include lithium, magnesium, aluminum, titanium, iron, copper, zinc, nickel, cobalt, lead, tin, zirconium, hafnium, vanadium, niobium, tantalum, tungsten, molybdenum, chromium, manganese, gold, silver, platinum, ruthenium, rhodium, palladium, gallium, indium, thallium, calcium, strontium, barium and alloys thereof.

4. The method according to claim 1, characterized in that: Compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium include oxides, chlorides, fluorides, hydrides, nitrides, sulfides, carbides, or intermetallic compounds of cerium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

5. The method according to claim 1, characterized in that Mechanical ball milling includes ball milling using a planetary ball mill, a high-energy ball mill, a stirring ball mill or a vibrating ball mill.

6. The method according to claim 1, characterized in that Solution heat treatment includes vacuum solution heat treatment, atmosphere protection solution heat treatment or solution heat treatment in conventional atmospheric environment.

7. The method according to claim 1, characterized in that The temperature of the solid solution heat treatment is 100-3000° C., and the time of the solid solution heat treatment is 0.1-100 hours.

8. A spray powder, characterized in that: It is prepared by the method according to any one of claims 1 to 7, and the size of the spraying powder is 0.1-200 μm.

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