Preparation Method and Application of a High-Cost Performance Alloy

Abstract

The present invention provides a method for preparing a high cost-effective alloy and its application, belonging to the technical field of alloy manufacturing. The alloy raw materials of the present invention include iron powder, cobalt powder, nickel powder, titanium carbide powder and tungsten carbide powder. By optimizing the composition ratio of the alloy raw materials and adopting a refined preparation process, multi-stage ball milling, spray drying, vacuum sintering and annealing treatment steps and optimized parameters are set during the preparation process to ensure the uniformity and density of the alloy. In the field of manufacturing low-grade iron-containing lawn mower blades and woodworking blades, while meeting the requirements for alloy performance, the cost is effectively reduced. This cost advantage not only improves the cost performance of the product, but also enables the enterprise to expand the market more smoothly.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloy manufacturing, and relates to a preparation method and application of a high-cost-performance alloy. Background Art

[0002] In the current highly competitive market environment, manufacturing enterprises of low-grade iron-containing lawn mower blades and woodworking blades are facing major challenges. With the increase in industry participants, the phenomenon of product homogenization is serious, resulting in fierce price competition. However, the cost of traditional materials is high. How to reduce the cost of producing products while ensuring product performance is a problem faced by current enterprises.

[0003] Therefore, developing an alloy material that can meet performance requirements and has a cost advantage has become an urgent task in the industry. Summary of the Invention

[0004] The object of the present invention is to address the above problems existing in the prior art and propose a preparation method and application of a high-cost-performance alloy.

[0005] The object of the present invention can be achieved by the following technical solutions: A preparation method of a high-cost-performance alloy includes the following steps:

[0006] S1 Ball milling: Add alloy raw materials into a ball milling device containing anhydrous ethanol, and perform ball milling operations to obtain a ball milled mixture.

[0007] The ball milling operations are divided into three stages, namely preliminary grinding, medium fine grinding, and final fine grinding in sequence.

[0008] The alloy raw materials include iron powder, cobalt powder, nickel powder, titanium carbide powder, and tungsten carbide powder; the iron powder can pass through a 300-mesh sieve, and the carbon content of the iron powder is 0.86%; the particle size of the cobalt powder is 1-2 μm; the particle size of the nickel powder is 1-2 μm; the particle size of the titanium carbide is 2-3 μm; the particle size of the tungsten carbide is 2-3 μm.

[0009] In the alloy raw materials, by weight ratio, iron powder:cobalt powder:nickel powder:titanium carbide powder:tungsten carbide powder is 15:2.5:2.5:20:60; by mass-volume ratio, the weight of the alloy raw materials: the volume of anhydrous ethanol is 300-310 kg:95-100 L.

[0010] Functions of ball milling: Reduction of particle size: Ball milling can grind large-particle alloy raw materials into finer powders, increasing the surface area. The refined particles help to improve the uniformity and performance of the alloy. Mixing uniformity: During the ball milling process, powders of different components will be continuously collided and rubbed, enabling the components to be fully mixed, thus ensuring the uniform composition of the alloy and finally forming consistent material properties.

[0011] The multi-stage ball milling process has significant advantages in alloy preparation, which can effectively improve material properties and reduce production costs. The specific benefits are as follows: 1. Gradually control particle size refinement and improve material uniformity: Preliminary grinding: In the initial stage, the main goal is to gradually reduce the particle size of the alloy raw materials from large particles to a medium level. This step helps to quickly break large particles and improve the ball milling efficiency in subsequent stages. Medium fine grinding: In this stage, through longer grinding time and higher ball milling energy, the material particles are further refined. Medium fine grinding helps to promote full mixing between different components while maintaining a reasonable particle size, improving the uniformity of the alloy. Final fine grinding: In the final stage, the particle size is further reduced; this stage makes the alloy powder particles very fine, increasing the specific surface area, which helps to improve the densification and strength of the alloy in subsequent sintering or other forming processes. Improve ball milling efficiency and save time and energy: 2. Stagewise optimize energy use: Through multi-stage ball milling, less energy is used for rough grinding in the initial stage, while a higher energy density is adopted in the fine grinding stage. This strategy can maximize the efficacy of the ball milling equipment, avoid excessive energy consumption in the initial stage, and save production time and energy costs. 3. Reduce equipment wear and extend equipment life: Reduce mechanical load: Using larger particles and lower energy in the preliminary grinding stage can effectively reduce the impact and wear on the ball milling equipment, avoiding excessive burden on the equipment caused by high-intensity grinding at one time. Subsequently increasing the energy gradually helps to maintain the stable operation of the equipment, thereby extending the equipment life and reducing maintenance and replacement costs. 4. Improve mixing uniformity and ensure consistent alloy properties: Enhance the mixing effect of each component: Through multi-stage ball milling, iron powder, cobalt powder, nickel powder, titanium carbide powder, and tungsten carbide powder are fully mixed during the ball milling process. At each stage, the powders of different components will undergo repeated collisions, frictions, and refinements, making them evenly distributed to ensure that the proportion of each component in the final alloy is consistent. This uniformity is an important factor in ensuring consistent alloy properties.

[0012] The reasons for using anhydrous ethanol include: Lubrication effect: Anhydrous ethanol can play a lubricating role during the ball milling process, reducing the friction between powders, which helps to improve the ball milling efficiency and reduce equipment wear. Reduce heat: During the ball milling process, the heat generated due to friction may cause powder sintering or other adverse reactions. The liquid medium can absorb part of the heat and keep the material within a suitable temperature range. Improve mixing uniformity: The presence of anhydrous ethanol makes it easier for the powders of each component to disperse during the ball milling process, helping to improve the mixing uniformity.

[0013] S2 Drying: Spray dry the ball-milled mixed material to obtain the dried mixed material;

[0014] S3 Compression Molding: Select paraffin wax as the molding agent. Using isostatic pressing technology, the dry mixed materials are pressed into shape by the cold pressing method to obtain a pre-sintered body. By weight ratio, paraffin wax: dry mixed materials is 2.3 - 2.4:100. During the compression molding process, an anti-adhesion layer is coated on the surface of the pressing mold.

[0015] Reasons for selecting paraffin wax: Good formability: Paraffin wax has good fluidity at high temperatures and can effectively fill the shape of the mold. This property helps to form a uniform pre-sintered body during the pressing process, ensuring the density and structural consistency of the product.

[0016] Excellent demolding property: Paraffin wax has stable chemical properties and good demolding performance, reducing adhesion to the mold during molding. This can reduce wear during compression molding, extend the service life of the mold, and lower subsequent maintenance costs. Appropriate bonding property: Paraffin wax can play a good bonding role at a certain temperature, enabling better bonding between different particles and improving the strength of the formed body.

[0017] Molding effect: Uniform distribution: When the ratio of paraffin wax to dry mixed materials is 2.3 - 2.4:100, paraffin wax can provide sufficient lubrication to ensure the uniform distribution of the dry mixed materials in the mold, reducing the situation of local over-compaction or looseness, thereby improving the consistency of the product. Reducing stress concentration: The paraffin wax ratio can effectively reduce the stress concentration of the material during the pressing process, reducing the risk of cracking or deformation and improving the overall performance of the formed body.

[0018] Cost consideration: Reasonable material cost: Paraffin wax has a relatively low cost compared to other molding agents (such as resins or polymers). Using paraffin wax as the molding agent can not only maintain a low material cost but also reduce production costs to a certain extent, making the preparation of the alloy more economical. Effective dosage control: The ratio of 2.3 - 2.4:100 can effectively control the dosage of paraffin wax, avoiding cost waste caused by excessive use, while still ensuring the achievement of the molding effect. This control makes the production process more flexible and controllable.

[0019] Selecting paraffin wax as the molding agent and using a ratio of 2.3 - 2.4:100 can not only improve the molding effect and performance of the alloy but also effectively control costs, making the preparation process more economical and efficient.

[0020] S4 Vacuum Sintering: Use a vacuum sintering integrated furnace to perform vacuum sintering operations on the pre-sintered body to obtain the alloy.

[0021] The specific steps of the vacuum sintering operation are as follows: S4.1 Dewaxing: Dewaxing preheating stage: Put the pre-sintered body into the vacuum sintering integrated furnace, heat the temperature in the furnace to 110 - 120 °C, and the heat preservation time is T1; Dewaxing main stage: After the heat preservation ends, raise the temperature to 380 - 420 °C at a rate of 3 - 5 °C / min; The heat preservation time is T2. Introduce inert gas during the dewaxing stage to promote the discharge of paraffin and prevent re-deposition;

[0022] Preheating at 110 - 120 °C: Within this temperature range, the paraffin can be effectively softened and start to volatilize, reducing the temperature shock in the subsequent temperature stage, thereby avoiding excessive thermal stress on the alloy raw materials and reducing the risk of cracking of the formed body.

[0023] The temperature rising range of 380 - 420 °C: Within this temperature range, the paraffin will be completely removed.

[0024] The reasons for choosing a heating rate of 3 - 5 °C / min are as follows: 1. Reduce thermal stress and deformation: Control temperature change: A slow heating rate helps prevent thermal stress concentration caused by too rapid temperature change, avoiding deformation or cracking of the alloy raw materials during heating. This uniform heating can maintain the structural integrity of the formed body. 2. Promote the effective volatilization of paraffin: Avoid bubble formation: If paraffin volatilizes rapidly during heating, it may lead to the generation and residue of bubbles, which will affect the density and uniformity of the alloy. A heating rate of 3 - 5 °C / min can ensure the gradual release of paraffin, thus reducing the risk of bubble generation and ensuring the denseness of the alloy. 3. Optimize the microstructure of the alloy: Maintain phase stability: At a lower heating rate, alloy raw materials (such as iron, cobalt, nickel, titanium carbide, and tungsten carbide) can maintain a stable microstructure for a longer time, reducing phase transformation or precipitation phenomena caused by high temperature. This helps maintain the overall performance of the alloy and avoid brittleness or non-uniformity. 4. Improve the uniformity of the sintering process: Promote the uniform distribution of materials: Slow heating can ensure that the temperature distribution of the alloy raw materials is more uniform throughout the heating process, contributing to the overall sintering uniformity of the materials, thereby improving the density and mechanical properties of the alloy.

[0025] S4.2 Main stage of vacuum sintering: Initial preheating stage: Under an inert atmosphere, raise the temperature in the furnace to 790 - 800 °C at a heating rate of 4 - 5 °C / min, and the heat preservation time is T3; Intermediate heating stage: After the initial heating stage ends, raise the temperature in the furnace to 1290 - 1300 °C at a heating rate of 2 - 3 °C / min, and the heat preservation time is T4; Target heating stage: After the intermediate heating stage ends, raise the temperature in the furnace to 1410 - 1420 °C, and the heat preservation time is T5. After the heat preservation ends, obtain the initial alloy;

[0026] Setting different heating stages is mainly related to the raw materials of the alloy and the expected physical and chemical properties. The reasons for setting these specific temperatures are as follows: Initial preheating stage at 790 - 800°C: The main purpose of this stage is to remove any possible residual organic substances in the alloy and ensure the initial sintering between alloy powders. During this stage, diffusion and adhesion begin to occur on the surface of the alloy powder particles, but they are not fully sintered. This helps to form a preliminary mechanical connection between the powder particles, providing a better basis for subsequent high-temperature sintering. Intermediate heating stage at 1290 - 1300°C: In this stage, the main purpose is to promote the sintering of the main components in the alloy, especially titanium carbide and tungsten carbide. Tungsten carbide (WC) and titanium carbide (TiC) have very high melting points (about 2870°C and 3140°C respectively), and although the temperature in this stage does not reach their melting points, it is sufficient to promote better bonding of these hard alloy components through diffusion in the solid state. This temperature range is crucial for achieving stronger chemical and mechanical bonding between various components in the alloy, such as the metal matrix of iron, cobalt, and nickel, and the hard carbide particles (such as WC and TiC), which is essential for improving the overall properties of the alloy, such as hardness and wear resistance. Target heating stage at 1410 - 1420°C: Selecting 1410 - 1420°C as the final sintering temperature is a comprehensive decision based on the characteristics of the raw materials, as well as performance and cost considerations. Sintering characteristics of raw materials: Titanium carbide (TiC) and tungsten carbide (WC) used in the alloy both have very high melting points (about 3140°C and 2870°C respectively). Although 1410 - 1420°C is far below these melting points, this temperature is high enough to promote effective diffusion and chemical bonding between these hard carbides and the metal matrix (iron, cobalt, nickel). At this temperature, the hard carbides do not melt, but can combine with other metal atoms through solid-state diffusion to form a strong metal matrix network, enhancing the overall mechanical properties of the alloy. Cost-effectiveness: Sintering at or above the melting point of the carbide will greatly increase energy consumption and equipment wear, so sintering at a lower temperature can effectively reduce production costs. Sintering at 1410 - 1420°C can optimize energy and costs without sacrificing material performance. This temperature range provides an economically viable method to achieve the desired sintering effect through reasonable temperature control. Performance optimization: Sintering at 1410 - 1420°C can promote the bonding between carbides and the metal matrix, improving the density and uniformity of the material.

[0027] The different heating rates (4 - 5 °C / min and 2 - 3 °C / min) are determined according to the thermophysical properties and sintering behavior of the alloy raw materials, and the reasons are as follows: In the initial preheating stage, a heating rate of 4 - 5 °C / min helps to uniformly heat the pre-sintered body and reduce the thermal stress caused by the temperature gradient. In this stage, due to the different thermal expansion coefficients between the alloy raw materials (especially iron powder, cobalt powder, nickel powder) and carbides (titanium carbide, tungsten carbide), the control of the temperature gradient is particularly important to avoid cracks or other structural defects inside the material.

[0028] Reasons for setting the heating rate of 2 - 3 °C / min: The slow heating rate can make the temperature in the furnace more uniform, avoid local overheating or cooling, and thus promote the uniform sintering of the material, improving the mechanical properties and structural integrity of the final alloy.

[0029] The vacuum sintering integrated furnace adopted in the present invention integrates processes such as dewaxing - pre-sintering - vacuum sintering - rapid cooling, etc., and can complete its entire process in the furnace at one time. The vacuum sintering integrated furnace is composed of a stainless-steel outer shell with clamps, a working inner tank, a heater, a heat-insulating layer, a thermocouple, a guide rail with rollers, three electrodes, and a rapid cooling device. In addition, the dewaxing system of the vacuum sintering integrated furnace is composed of a horizontal cylindrical wax collector, a vertical cylindrical separator, and a shell-and-tube condenser.

[0030] The electric control system of the vacuum sintering furnace is composed of a transformer, a main circuit frame, and an electric control cabinet, and is used to control the heating rate and temperature of the furnace;

[0031] The vacuum system is composed of a fore-stage mechanical pump, a Roots pump, vacuum pipelines, vacuum valves, and pressure switch pipe components, and is divided into two branches. One is used to evacuate the furnace chamber, and the other is used to evacuate the inside of the furnace liner for dewaxing. A bypass valve and a pressure automatic regulating valve are provided on the main air extraction pipeline.

[0032] S4.3 Cooling: The initial alloy is successively subjected to initial cooling operation, medium-temperature rapid cooling operation, low-temperature slow cooling operation, and natural cooling operation to obtain an intermediate alloy;

[0033] In the initial cooling operation, the cooling target temperature is 1000 - 1050 °C. In the medium-temperature rapid cooling operation, the rapid cooling system of the vacuum integrated furnace is used for cooling, and the cooling target temperature is 500 - 550 °C. In the low-temperature slow cooling operation, the cooling target temperature is 50 - 80 °C;

[0034] The settings for the three cooling stages are crucial, especially from the perspectives of the hardness and tensile strength of the alloy. These temperature settings reflect the fine-tuning of the control over the alloy's microstructure, aiming to optimize the alloy's ultimate physical properties. Initial cooling to 1000 - 1050 °C: In this stage, the alloy starts to cool from the high-temperature sintered state. The temperature range of 1000 - 1050 °C is selected for the initial cooling to allow the different components in the alloy (such as iron, cobalt, nickel, and carbides) to gradually adapt to the temperature drop, thereby reducing internal cracks caused by thermal stress. Slow cooling in this temperature range helps maintain the stability of the alloy's microstructure and prevent phase changes and non-uniform lattice contractions caused by rapid cooling. Medium-temperature rapid cooling to 500 - 550 °C: Rapid cooling is mainly adopted in the medium-temperature stage to lock in the microstructure formed in the alloy, especially those beneficial phases formed at high temperatures. In addition, rapid cooling can promote the fine distribution of certain carbides (such as titanium carbide and tungsten carbide) in the metal matrix, thereby significantly enhancing the hardness and wear resistance of the alloy. This temperature range ensures a good combination of hard phases and ductile matrix in the alloy's microstructure to achieve high hardness and good tensile strength. Low-temperature slow cooling to 50 - 80 °C: The final slow cooling helps eliminate the residual stress that may be generated during rapid cooling and further stabilizes the alloy's microstructure. This temperature range allows the alloy's grains to be fully relaxed, thereby reducing the brittleness of the material and improving its overall mechanical properties. In addition, slow cooling helps optimize the tensile strength of the alloy because it allows for more uniform crystal growth and smooth phase boundary transitions at the microscale.

[0035] S5 annealing: Put the intermediate alloy into a vacuum sintering furnace, raise the furnace temperature to 400 - 450 °C, after holding for time T6, cool it naturally to room temperature to obtain an alloy with high cost performance.

[0036] The reason for setting the annealing temperature at 400 - 450 °C is determined through multiple experiments based on the requirements of the alloy raw materials and properties. The main reasons are as follows: 1. Reducing internal stress: After vacuum sintering, there are internal stresses in the alloy, especially in the case where there are phase changes in the material. The annealing temperature of 400 - 450 °C can effectively reduce these internal stresses, thereby improving the toughness and crack resistance of the material. 2. Phase structure stability: Phase transformation: In this temperature range, the microstructure of the alloy usually reaches a balanced state, ensuring the phase stability of the alloy. For alloys containing elements such as cobalt and nickel, an appropriate annealing temperature can promote the phase transformation of the material to be more stable, thereby improving the mechanical properties of the alloy. 3. Optimizing grain size: The temperature range of 400 - 450 °C helps form a more uniform grain structure. 4. Reducing brittleness: The alloy may exhibit brittleness after sintering, and the annealing temperature can help alleviate this problem, improve the toughness of the material, and ensure better performance in practical applications.

[0037] Preferably, in step S1, in the ball milling operation, the ball-to-material ratio is 4:1; the ball milling medium is ceramic balls; in the preliminary grinding, the diameter of the ball milling medium is 10 mm, the ball milling speed is 36 - 40 RPM, and the ball milling time is 12 hours; in the medium fine grinding, the diameter of the ball milling medium is 8 mm, the ball milling speed is 40 - 45 RPM, and the ball milling time is 24 hours; in the final fine grinding, the diameter of the ball milling medium is 6 mm, the ball milling rate is 45 - 50 RPM, and the ball milling time is 12 hours.

[0038] Preferably, in step S2, the spray drying operation parameters are set as follows: inlet air temperature: 180 - 200 °C; outlet air temperature: 60 - 70 °C; spray pressure: 2 - 2.5 MPa; gas flow rate: 200 - 300 m 3 / h; collection device: cyclone separator and bag filter; filtration parameter: 1 - 2 um.

[0039] Preferably, in step S3, the specific steps of pressing and forming are as follows: mixing: heating the paraffin to a liquid state and then mixing it evenly with the dried mixed material to obtain a pre-pressed material; filling: filling the pre-pressed material into a mold pre-coated with an anti-sticking layer; isostatic pressing: using a high-pressure isostatic press to press at a pressure of 40 - 60 MPa, demolding: after the pressing is completed, taking out the formed body in the mold to obtain a pre-sintered body;

[0040] The specific material of the anti-sticking layer is polytetrafluoroethylene.

[0041] Preferably, in step S4, the inert gas is argon,

[0042] In step S4.1, the parameters are as follows: the vacuum degree is 4 - 5×10^-2 torr; T1 is 30 - 60 minutes; T2 is 160 - 180 minutes;

[0043] In step S4.2, the parameters are as follows: in the initial preheating stage, the vacuum degree is 1 - 2×10^-4 torr; T3 is 35 - 40 minutes; in the intermediate heating stage, the vacuum degree is 8 - 8.5×10^-5 torr; T4 is 20 - 25 minutes; in the target heating stage, the vacuum degree is 4 - 5×10^-5 torr, and T4 is 90 - 110 minutes.

[0044] Specific vacuum parameters are set mainly to optimize the atmosphere control during dewaxing and sintering processes to ensure the quality and performance of the alloy. Paraffin wax is used as a binder in the pre-sintered body and it must be completely removed at high temperatures. Using a vacuum environment can lower the boiling point of paraffin wax, enabling it to evaporate effectively at a lower temperature, thus reducing residues. The selected vacuum range (4 - 5×10^-2 torr) helps to quickly expel the paraffin gas, preventing these gases from re-condensing or depositing inside the material, which could lead to material defects. This range of vacuum has been verified to be sufficient to complete these functions while avoiding the additional costs associated with using a lower vacuum.

[0045] During the sintering process, the control of vacuum is related to the kinetics of heat treatment. A lower air pressure helps with heat transfer during the heating process, making the heat more evenly distributed in the material and preventing cracks or deformations caused by thermal stress. Vacuum at the initial preheating stage (1 - 2×10^-4 torr): Optimize material density and structure: A deeper vacuum helps to further remove any residual gases and volatile substances, providing a cleaner environment for sintering. Improve material properties: By reducing the introduction of pores and impurities, the mechanical properties and chemical uniformity of the alloy are improved. Vacuum at the intermediate and target heating stages (8 - 8.5×10^-5 torr and 4 - 5×10^-5 torr): Coordinate temperature and air pressure: The temperature increases significantly during these stages, and precise control of the vacuum is required to match the needs of heat diffusion, ensuring the uniform fusion of alloy components and grain growth. Avoid gas re-adsorption: A lower vacuum helps to prevent gases from re-adsorbing onto the material surface during sintering at high temperatures, which could cause non-uniform sintering and performance degradation.

[0046] Overall, by precisely controlling the vacuum, the dewaxing and sintering processes can be effectively managed and optimized to improve the overall performance and reliability of the alloy.

[0047] Preferably, in step S4.3, during the initial cooling operation, the cooling rate is 3 - 4 °C / minute; during the rapid cooling operation at medium temperature, the rapid cooling system of the vacuum integrated furnace is used to cool with argon gas; during the slow cooling operation at low temperature, the cooling rate is 1 - 2 °C / minute.

[0048] The cooling rate at the initial cooling stage is 3 - 4 °C / minute: This rate is relatively mild and is used to gradually transition from high temperature to medium temperature, which helps to prevent thermal stress caused by temperature differences, thereby reducing thermal cracks or other defects caused by thermal stress in the material.

[0049] Medium-temperature rapid cooling stage: In this stage, the rapid cooling system of the vacuum furnace is used and an inert gas is filled to rapidly cool to a lower temperature (500 - 550 °C). Rapid cooling helps to freeze the favorable characteristics of the material microstructure, such as fine grain structure, which is very important for improving the mechanical properties of the material.

[0050] The cooling rate in the low-temperature slow cooling stage is 1 - 2 °C / min: Slow cooling helps to further reduce thermal stress and allows for more uniform cooling, thereby improving the structural integrity and performance of the material.

[0051] Preferably, in step S5, the temperature is raised to 400 - 450 °C at a heating rate of 3 - 4 °C / min; T6 is 30 - 35 minutes.

[0052] The application of a high cost-effective alloy, the high cost-effective alloy is used to make low-grade iron-containing lawn mower blades and woodworking blades products. In the use of the high cost-effective alloy, high-frequency welding technology is adopted for welding.

[0053] The beneficial effects of the present invention are as follows: By optimizing the composition ratio of the alloy raw materials and adopting a refined preparation process, parameters for multi-stage ball milling, spray drying, vacuum sintering, and annealing treatment are set during the preparation process to ensure the uniformity and density of the alloy. While meeting the performance requirements, the cost is effectively reduced. This cost advantage not only improves the cost performance of the product but also enables the enterprise to expand the market more smoothly. Description of the Drawings

[0054] Figure 1 It is the metallographic diagram of the high cost-effective alloy in Specific Example 1. Detailed Embodiments

[0055] The following are specific embodiments of the present invention and in combination with the drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments. Specific Example 1:

[0057] A preparation method of a high cost-effective alloy includes the following steps: S1 Ball milling: Add the alloy raw materials into a ball milling device containing anhydrous ethanol, perform ball milling operations to obtain a ball milled mixed material.

[0058] The ball milling operations are divided into three stages, namely preliminary grinding, medium fine grinding, and final fine grinding; in the ball milling operations, the ball-to-material ratio is 4:1; the ball milling medium is ceramic ball milling balls.

[0059] The alloy raw materials include iron powder, cobalt powder, nickel powder, titanium carbide powder, and tungsten carbide powder; the iron powder can pass through a 300-mesh sieve, and the carbon content of the iron powder is 0.86%; the particle size of the cobalt powder is 1 - 2 um; the particle size of the nickel powder is 1 - 2 um; the particle size of the titanium carbide is 2 - 3 um; the particle size of the tungsten carbide is 2 - 3 um.

[0060] In the alloy raw materials, by weight ratio, iron powder:cobalt powder:nickel powder:titanium carbide powder:tungsten carbide powder is 15:2.5:2.5:20:60; by mass-volume ratio, alloy raw material weight:anhydrous ethanol volume is 300:95;

[0061] In the preliminary grinding, the diameter of the ball milling medium is 8 mm, the ball milling speed is 36 RPM, and the ball milling time is 12 hours; in the medium fine grinding, the diameter of the ball milling medium is 5 mm, the ball milling speed is 42 RPM, and the ball milling time is 24 hours; in the final fine grinding, the diameter of the ball milling medium is 3 mm, the ball milling rate is 45 RPM, and the ball milling time is 12 hours.

[0062] S2 Drying: Spray dry the ball-milled mixed material to remove anhydrous ethanol and obtain the dried mixed material;

[0063] The drying operation parameters are set as follows: inlet air temperature: 180 °C; outlet air temperature: 70 °C; spray pressure: 2 - 2.5 MPa; gas flow rate: 200 - 300 m 3 / h; collection device: cyclone separator and bag filter;

[0064] S3 Compression molding: Select paraffin as the molding agent, and use the isostatic pressing technology to press the dried mixed material into shape by the cold pressing method to obtain the pre-sintered body; by weight ratio, paraffin:dried mixed material is 2.3 - 2.4:100; during the compression molding process, the surface of the pressing mold is coated with an anti-sticking layer;

[0065] The specific steps of compression molding are as follows: Mixing: Heat the paraffin to a liquid state and then mix it evenly with the dried mixed material to obtain the pre-pressed material; Filling: Fill the pre-pressed material into a mold pre-coated with an anti-sticking layer; Isostatic pressing: Start the high-pressure isostatic press and adjust the pressure to 50 MPa for pressing; Demolding: After pressing, reduce the pressure and then take out the molded body in the mold to obtain the pre-sintered body;

[0066] The specific material of the anti-sticking layer is polytetrafluoroethylene.

[0067] S4 Vacuum sintering: Use a vacuum sintering integrated furnace to perform vacuum sintering on the pre-sintered body to obtain the alloy;

[0068] The specific steps of the vacuum sintering operation are as follows: S4.1 Dewaxing: Dewaxing preheating stage: Put the pre-sintered body into the vacuum sintering integrated furnace, heat the temperature in the furnace to 110 °C, and the holding time is T1; Dewaxing main stage: After the holding is over, raise the temperature to 420 °C at a rate of 3 - 5 °C / min; the holding time is T2, and an inert gas is introduced during the dewaxing stage to promote the discharge of paraffin and prevent re-deposition;

[0069] S4.2 Main stage of vacuum sintering: Initial preheating stage: Under an inert atmosphere, the temperature inside the furnace is raised to 790 - 800 °C at a heating rate of 4 °C / min, and the holding time is T3; Intermediate heating stage: After the initial heating stage ends, the temperature inside the furnace is raised to 1300 °C at a heating rate of 2 °C / min, and the holding time is T4; Target heating stage: After the intermediate heating stage ends, the temperature inside the furnace is raised to 1420 °C, and the holding time is T5. After the holding ends, the initial alloy is obtained;

[0070] S4.3 Cooling: The initial alloy is successively subjected to initial temperature reduction operation, medium-temperature rapid cooling operation, low-temperature slow temperature reduction operation, and natural cooling operation to obtain the intermediate alloy;

[0071] In the initial temperature reduction operation, the cooling target temperature is 1050 °C. In the medium-temperature rapid cooling operation, the rapid cooling system of the vacuum integrated furnace is used for cooling, and the cooling target temperature is 550 °C. In the low-temperature slow temperature reduction operation, the cooling target temperature is 60 °C;

[0072] The inert gas is argon. In step S4.1, the parameters are as follows: The vacuum degree is 5×10^-2 torr; T1 is 50 minutes; T2 is 170 minutes;

[0073] In step S4.2, the parameters are as follows: In the initial preheating stage, the vacuum degree is 2×10^-4 torr; T3 is 38 minutes; In the intermediate heating stage, the vacuum degree is 8×10^-5 torr; T4 is 22 minutes; In the target heating stage, the vacuum degree is 5×10^-5 torr, and T4 is 100 minutes.

[0074] In the initial temperature reduction operation, the temperature reduction rate is 4 °C / min; In the medium-temperature rapid cooling operation, the rapid cooling system of the vacuum integrated furnace is used to cool with argon gas filled; In the low-temperature slow temperature reduction operation, the temperature reduction rate is 1 °C / min.

[0075] As Figure 1 shown, S5 Annealing: The intermediate alloy is placed in a vacuum sintering furnace, and the temperature is raised to 450 °C at a heating rate of 3 °C / min; Hold for 35 minutes and cool naturally to room temperature to obtain the high-cost performance alloy.

[0076] The high-cost performance alloy prepared above and the national standard YG8 alloy are respectively made into saw blades, and the results are shown in Table 1 and

[0077] Table 2 as follows:

[0078]

[0079]

[0080] Table 1

[0081]

[0082] Table 2

[0083] By analyzing Table 1 and Table 2, the analysis results are as follows: 1. Cutting performance comparison: Number of cut iron nails: Both are 300, indicating that when cutting the same number of iron nails, their performances are comparable. Cutting distance for wood: Both are 200 meters, showing that in terms of wood cutting, the high-cost-performance alloy is also comparable to YG8. Wear situation: Neither has chipping, indicating that during use, the high-cost-performance alloy performs similarly to YG8 in terms of durability and cutting stability. 2. Material property comparison: Hardness: It shows that the anti-wear capabilities of both are similar. Density: The density of the high-cost-performance alloy is 9.5, while that of YG8 is 14.8. The lower density means that the high-cost-performance alloy is lighter during processing, which can reduce the machine load and operation difficulty. 3. Market price: The market price of YG8 is 350 yuan / kg, while that of the high-cost-performance alloy is 260 yuan / kg. The advantage of the high-cost-performance alloy in terms of market price can reduce production costs and enhance the competitiveness of the enterprise.

[0084] Comprehensive analysis: Performance balance: The two materials perform similarly in cutting performance. The lower density and price advantage of the high-cost-performance alloy give it an advantage in terms of economy and lightness. Cost-effectiveness: Using the high-cost-performance alloy can reduce material costs while maintaining cutting performance and durability.

[0085] Specific implementation 2:

[0086] When preparing the alloy using the method provided in Specific Example 1, only the final sintering temperature in step S4.2 is adjusted. For different sintering temperatures, the performances of the prepared alloys are shown in Table 3:

[0087]

[0088] Table 3

[0089] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, but will not deviate from the spirit of the present invention or exceed the defined scope. Although the present invention has been described in detail in the drawings and the foregoing description, such description is considered to be illustrative or exemplary rather than restrictive. It should be understood that within the scope of the following claims, those of ordinary skill in the art can make changes and modifications.

Claims

1. A preparation method of a high cost-effective alloy, characterized in that, The preparation method of the high cost-effective alloy comprises the following steps: S1 Ball milling: Add the alloy raw materials into a ball milling device filled with anhydrous ethanol, and perform ball milling operation to obtain a ball milled mixture. The ball milling operation is divided into three stages, namely preliminary grinding, medium fine grinding and final fine grinding in sequence. The alloy raw materials include iron powder, cobalt powder, nickel powder, titanium carbide powder and tungsten carbide powder; the iron powder can pass through a 300-mesh sieve, and the carbon content of the iron powder is 0.86%; the particle size of the cobalt powder is 1-2 μm; the particle size of the nickel powder is 1-2 μm; the particle size of the titanium carbide is 2-3 μm; the particle size of the tungsten carbide is 2-3 μm. In the alloy raw materials, by weight ratio, iron powder:cobalt powder:nickel powder:titanium carbide powder:tungsten carbide powder is 15:2.5:2.5:20:60; by mass-volume ratio, alloy raw material weight:anhydrous ethanol volume is 300-310 kg:95-100 L. S2 Drying: Perform spray drying operation on the ball milled mixture to obtain a dried mixture. S3 Compression molding: Select paraffin as the molding agent, and use isostatic pressing technology to press the dried mixture into shape by cold pressing method to obtain a pre-sintered body; by weight ratio, paraffin:dried mixture is 2.3-2.4:100; during the compression molding process, the surface of the pressing die is coated with an anti-sticking layer. S4 Vacuum sintering: Perform vacuum sintering operation on the pre-sintered body by using a vacuum sintering integrated furnace to obtain an alloy. The specific steps of the vacuum sintering operation are as follows: S4.1 Dewaxing: Dewaxing preheating stage: Put the pre-sintered body into the vacuum sintering integrated furnace, heat the temperature in the furnace to 110-120 °C, and the heat preservation time is T1; Dewaxing main stage: After the heat preservation ends, raise the temperature to 380-420 °C at a rate of 3-5 °C / min; the heat preservation time is T2, and an inert gas is introduced during the dewaxing stage to promote the discharge of paraffin and prevent re-deposition. S4.2 Vacuum sintering main stage: Initial preheating stage: Under an inert atmosphere, raise the temperature in the furnace to 790-800 °C at a heating rate of 4-5 °C / min, and the heat preservation time is T3; Intermediate heating stage: After the initial heating stage ends, raise the temperature in the furnace to 1290-1300 °C at a heating rate of 2-3 °C / min, and the heat preservation time is T4; Target heating stage: After the intermediate heating stage ends, raise the temperature in the furnace to 1410-1420 °C, and the heat preservation time is T5. After the heat preservation ends, obtain an initial alloy. S4.3 Cooling: Perform initial cooling operation, medium-temperature rapid cooling operation, low-temperature slow cooling operation and natural cooling operation on the initial alloy in sequence to obtain an intermediate alloy; in the initial cooling operation, the cooling target temperature is 1000-1050 °C, in the medium-temperature rapid cooling operation, use the rapid cooling system of the vacuum sintering integrated furnace for cooling, and the cooling target temperature is 500-550 °C, in the low-temperature slow cooling operation, the cooling target temperature is 50-80 °C. The inert gas is argon. In step S4.1, the parameters are as follows: the vacuum degree is 4-5×10^-2 torr; T1 is 30-60 minutes; T2 is 160-180 minutes. In step S4.2, the parameters are as follows: in the initial preheating stage, the vacuum degree is 1 - 2×10^-4 torr; T3 is 35 - 40 minutes; in the intermediate heating stage, the vacuum degree is 8 - 8.5×10^-5 torr; T4 is 20 - 25 minutes; in the target heating stage, the vacuum degree is 4 - 5×10^-5 torr, and T4 is 90 - 110 minutes; In step S4.3, in the initial cooling operation, the cooling rate is 3 - 4 °C / minute; in the medium-temperature rapid cooling operation, argon gas is filled for cooling by using the rapid cooling system of the vacuum sintering integrated furnace; in the low-temperature slow cooling operation, the cooling rate is 1 - 2 °C / minute; S5 Annealing: Put the intermediate alloy into the vacuum sintering furnace, raise the furnace temperature to 400 - 450 °C, after the holding time T6, cool it naturally to room temperature to obtain a high-cost performance alloy; raise the temperature to 400 - 450 °C at a heating rate of 3 - 4 °C / min; T6 is 30 - 35 minutes.

2. The preparation method of the high cost-effective alloy according to claim 1, characterized in that, In step S1, in the ball milling operation, the ball-to-material ratio is 4:1; the ball milling medium is ceramic ball milling balls; in the preliminary grinding, the diameter of the ball milling medium is 10 mm, the ball milling speed is 36 - 40 RPM, and the ball milling time is 12 hours; in the medium fine grinding, the diameter of the ball milling medium is 8 mm, the ball milling speed is 40 - 45 RPM, and the ball milling time is 24 hours; in the final fine grinding, the diameter of the ball milling medium is 6 mm, the ball milling rate is 45 - 50 RPM, and the ball milling time is 12 hours.

3. The preparation method of the high cost performance alloy according to claim 1, characterized in that In step S2, the spray drying operation parameters are set as follows: inlet air temperature: 180 - 200 °C; outlet air temperature: 60 - 70 °C; spray pressure: 2 - 2.5 MPa; gas flow rate: 200 - 300 m 3 / h.

4. The preparation method of the high cost-effective alloy according to claim 1, characterized in that, In step S3, the specific steps of pressing and forming are as follows: Mixing: Heat the paraffin to a liquid state, and then mix it evenly with the dry mixed material to obtain a pre-pressed material; Filling: Fill the pre-pressed material into a mold pre-coated with an anti-sticking layer; Isostatic pressing: Use a high-pressure isostatic press to press at a pressure of 40 - 60 MPa, Demolding: After the pressing is completed, take out the formed body in the mold to obtain a pre-sintered body; The specific material of the anti-sticking layer is polytetrafluoroethylene.

5. Application of a cost-effective alloy, an alloy prepared by the preparation method of the cost-effective alloy described in any one of the above claims 1-4, characterized in that, The high-cost performance alloy is used to make low-grade iron-containing lawn mower blades and woodworking blades products. In the use of the high-cost performance alloy, high-frequency welding technology is used for welding.

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