Iron-copper-molybdenum alloy powder, preparation method thereof and diamond sintered body

Abstract

The invention discloses iron-copper-molybdenum alloy powder which at least comprises the following components in percentage by weight: 75-90% of iron, 8-20% of copper and 1-5% of molybdenum. The iron-copper-molybdenum alloy powder is prepared through the steps that a soluble salt aqueous solution of iron, copper and molybdenum and alkali generate coprecipitation, the coprecipitation is dried to generate an oxide precursor, and then reduction is conducted; wherein the reduction operation comprises the steps of firstly reducing for 3.5 to 4.5 hours at the temperature of 650 to 680 DEG C, and then reducing for 1.5 to 2.5 hours at the temperature of 700 to 750 DEG C. By optimizing the component proportion and the preparation process, the prepared iron-copper-molybdenum alloy powder has excellent hardness and is suitable for production of various sintered diamond-like tools, and a prepared sintered body has excellent bending strength and has wide market prospects and remarkable application value.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy powders, and in particular relates to iron-copper-molybdenum alloy powder, a preparation method thereof, and a diamond sintered body. Background Art

[0002] Diamond tools are tools with a specific shape, performance, and purpose, manufactured using diamond particles or powder as the primary cutting and grinding material, along with other auxiliary materials. Diamond tools have a wide range of applications, including building materials and stone processing, machining, geological exploration, and mineral mining. Their use in these areas relies primarily on their high hardness and wear resistance, properties that are largely dependent on the tool's matrix material.

[0003] Common matrix materials used in existing technologies include iron-based and copper-based alloys. However, these alloys struggle to achieve optimal strength, hardness, wear resistance, and sintering properties simultaneously, limiting the performance of diamond tools. Therefore, developing an alloy powder that combines high strength, high hardness, and good sintering properties is an urgent need for industry development.

[0004] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0005] The object of the present invention is to provide an iron-copper-molybdenum alloy powder, a preparation method thereof, and a diamond sintered body. The iron-copper-molybdenum alloy powder has excellent hardness and is suitable for producing sintered diamond-like tools. The sintered diamond-like tools produced have excellent bending strength and can significantly improve the service life and working performance of the tools.

[0006] In order to achieve the above object, a specific embodiment of the present invention provides the following technical solutions:

[0007] An iron-copper-molybdenum alloy powder comprises at least the following components in weight percentage: 75%-90% iron, 8%-20% copper, and 1%-5% molybdenum;

[0008] The iron-copper-molybdenum alloy powder is prepared by co-precipitating a soluble salt solution of iron, copper and molybdenum with an alkali, drying the co-precipitate to form an oxide precursor, and then reducing the precursor. The reduction operation is first carried out at 650°C-680°C for 3.5h-4.5h, and then at 700°C-750°C for 1.5h-2.5h.

[0009] In one or more embodiments of the present invention, the Fe-Cu-Mo alloy powder has a Fisher grain size of less than 3 μm.

[0010] Another specific embodiment of the present invention provides a technical solution as follows:

[0011] A method for preparing iron-copper-molybdenum alloy powder comprises the following steps:

[0012] Dissolving a soluble salt of iron and a soluble salt of copper in water to prepare a first metal ion solution, and dissolving a soluble salt of molybdenum in water to prepare a second metal ion solution;

[0013] Heat the first metal ion solution to 50°C-70°C, add the second metal ion solution, then add alkali, and stir to react to form a coprecipitate;

[0014] The coprecipitate is filtered, washed, and dried to obtain a precursor;

[0015] The precursor is first reduced at 650° C.-680° C. for 3.5 h-4.5 h, and then reduced at 700° C.-750° C. for 1.5 h-2.5 h to obtain iron-copper-molybdenum alloy powder.

[0016] In one or more embodiments of the present invention, the total concentration of metal ions in the first metal ion solution is 1-3 mol / L; and the total concentration of metal ions in the second metal ion solution is 1-2 mol / L.

[0017] In one or more embodiments of the present invention, the drying temperature is 120° C. to 160° C., and the drying time is 6 hours to 8 hours.

[0018] In one or more embodiments of the present invention, the reduction is carried out under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s to 0.05 m / s.

[0019] In one or more embodiments of the present invention, the soluble iron salt is at least one of iron sulfate, nitrate, and chloride.

[0020] In one or more embodiments of the present invention, the soluble salt of copper is at least one of copper sulfate, nitrate, and chloride.

[0021] In one or more embodiments of the present invention, the soluble salt of molybdenum is ammonium molybdate.

[0022] Another specific embodiment of the present invention provides a technical solution as follows:

[0023] A diamond sintered body is prepared by using the iron-copper-molybdenum alloy powder.

[0024] Compared with the existing technology, the present invention optimizes the component ratio and preparation process, controls the reduction temperature and time, and allows the elements to diffuse into each other to achieve alloying. The iron-copper-molybdenum alloy powder has the following characteristics: high hardness and high strength, which improves the cutting and wear resistance of diamond tools; good sintering performance, suitable for industrial large-scale production; and is widely used in the production of sintered diamond-like tools such as saw blades, drill bits, and wire saws. DETAILED DESCRIPTION

[0025] To help those skilled in the art better understand the technical solutions of the present invention, the following clearly and completely describes the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0026] A specific embodiment of the present invention provides an iron-copper-molybdenum alloy powder, comprising at least the following components in weight percentage: 75%-90% iron, 8%-20% copper, and 1%-5% molybdenum; the iron-copper-molybdenum alloy powder is prepared by co-precipitating a soluble salt solution of iron, copper, and molybdenum with an alkali, drying the co-precipitate to form an oxide precursor, and then reducing the resulting mixture; wherein the reduction operation is first performed at 650°C-680°C for 3.5h-4.5h, and then at 700°C-750°C for 1.5h-2.5h.

[0027] Specifically, iron, as the main component of the alloy powder, can ensure that the alloy has high strength and hardness by controlling its content. If the content is too high, it may have a negative impact on subsequent sintering, affecting the density of the alloy, and thus may reduce the strength of the alloy. Copper can play a strengthening role in the alloy, which can improve the strength and toughness of the alloy. The appropriate content can significantly improve the mechanical properties of the alloy. However, if the content is too high, it is easy to leave pores in the alloy, which will reduce the mechanical properties of the alloy. Molybdenum can promote alloy densification and improve the alloy microstructure during the sintering process, thereby improving the mechanical properties of the alloy. If its content in the alloy is too high, it is easy to increase the difficulty of sintering and reduce the mechanical properties of the alloy.

[0028] The co-precipitation-co-reduction method is used to prepare iron-copper-molybdenum alloy powder, which allows the iron, copper, and molybdenum elements to be evenly distributed in the alloy powder, improving the mechanical properties of the alloy. More importantly, different reduction temperatures are used during the reduction process. The reduction is first carried out at a lower temperature to remove the vast majority of oxygen and water vapor, and then at a higher temperature to remove the remaining oxygen and promote diffusion alloying between the elements at high temperature. In addition, the reduction time at high temperature is relatively short, which can reduce the grain growth of the powder. The finer the grains, the more it helps to improve the strength and hardness of the alloy, and also helps to improve the sintering density, so that the final alloy has excellent mechanical properties.

[0029] Furthermore, the Fe-Cu-Mo alloy powder has a Fisher particle size of less than 3 μm.

[0030] Specifically, smaller Fe particle size helps to improve the density of sintering, thereby improving the strength and hardness of the alloy.

[0031] Another specific embodiment of the present invention provides a method for preparing iron-copper-molybdenum alloy powder, comprising steps 1-4.

[0032] Step 1: dissolving a soluble salt of iron and a soluble salt of copper in water to prepare a first metal ion solution, and dissolving a soluble salt of molybdenum in water to prepare a second metal ion solution.

[0033] Specifically, the soluble salt of iron is at least one of iron sulfate, nitrate, and chloride; the soluble salt of copper is at least one of copper sulfate, nitrate, and chloride; and the soluble salt of molybdenum is ammonium molybdate. The total metal ion concentration in the first metal ion solution is 1-3 mol / L, and the metal ion concentration in the second metal ion solution is 1-2 mol / L.

[0034] Step 2: Heat the first metal ion solution to 50° C.-70° C., add the second metal ion solution, then add alkali, and stir to react to form a coprecipitate.

[0035] Specifically, the second metal ion solution is mixed with the first metal ion solution in a stoichiometric ratio and reacted with a base to form a corresponding coprecipitate. The base is at least one of sodium hydroxide, ammonia water, and sodium carbonate.

[0036] Step 3: Filter, wash and dry the coprecipitate to obtain a precursor.

[0037] Specifically, the coprecipitate is filtered, washed with water, and dried at 120° C. to 160° C. for 6 to 8 hours. The coprecipitate is dried to generate an oxide precursor.

[0038] Step 4: Reduce the precursor at 650-680° C. for 3.5-4.5 hours, and then reduce it at 700-750° C. for 1.5-2.5 hours to obtain iron-copper-molybdenum alloy powder.

[0039] Specifically, the reduction is carried out in a hydrogen atmosphere with a hydrogen volume flux of 0.03m / s to 0.05m / s. During the reduction, the oxygen elements contained in the precursor generate water and leave the system in the form of water vapor. By first reducing at a lower temperature, the oxygen elements outside the precursor are first removed, and then by reducing at a higher temperature, the oxygen elements inside the precursor are completely removed. At this time, when the remaining oxygen elements escape the system in the form of water vapor, due to the small amount, the impact caused by the escape of water vapor has little effect on the diffusion and alloying between the elements, so that the elements can diffuse normally to achieve alloying. If you choose to reduce directly at a higher temperature, the speed at which water vapor escapes the system is faster, which may affect the diffusion between the elements. Moreover, if the reduction is carried out at a higher temperature for a long time, the powder grains are likely to grow, which will reduce the strength and hardness of the alloy.

[0040] The present invention is further described in detail below with reference to specific embodiments.

[0041] Example 1

[0042] An iron-copper-molybdenum alloy powder comprises the following components in weight percentage: 75% iron, 19.6% copper, 5% molybdenum, 0.3% oxygen, and the balance being inevitable impurities, and has a Fisher grain size of 1.5 μm.

[0043] 3.734 kg of ferrous sulfate heptahydrate, 0.77 kg of copper sulfate pentahydrate, and 0.102 kg of ammonium molybdate were weighed and dissolved in deionized water to prepare a first metal ion solution. The total metal ion concentration in the first metal ion solution was 1 mol / L. Ammonium molybdate was dissolved in deionized water to prepare a second metal ion solution. The metal ion concentration in the second metal ion solution was 2 mol / L.

[0044] In addition, according to the stoichiometric ratio, 5% excess sodium hydroxide is weighed, that is, 5% more sodium hydroxide is weighed on the basis of the amount of sodium hydroxide required by the stoichiometric ratio, and the sodium hydroxide is dissolved in deionized water to prepare a sodium hydroxide solution with a concentration of 2 mol / L.

[0045] The first metal ion solution was heated to 50° C., and the second metal ion solution was slowly added to the first metal ion solution at a stirring speed of 100 r / min, and then the sodium hydroxide aqueous solution was slowly added. The stirring was continued for 30 minutes to allow the reaction to complete and generate a precipitate.

[0046] The precipitate was filtered, washed with deionized water several times, and then dried at 120° C. for 6 h to obtain the precursor.

[0047] Under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, the precursor was reduced at 650°C for 3.5 hours and then at 700°C for 1.5 hours. It was then crushed and sieved to obtain an iron-copper-molybdenum alloy powder.

[0048] The iron-copper-molybdenum alloy powder was placed into a steel mold with a size of 50*10*5mm and hot-pressed and sintered for 60 minutes at 30MPa and 850°C in a hydrogen atmosphere sintering furnace to obtain a diamond sintered body.

[0049] After testing, the diamond sintered body has a Rockwell hardness of HRB106, a bending strength of 1362MPa, and a density of 98.6%.

[0050] Example 2

[0051] An iron-copper-molybdenum alloy powder comprises the following components in weight percentage: 90% iron, 8% copper, 1.5% molybdenum, 0.4% oxygen, and the balance being inevitable impurities, and has a Fisher grain size of 2.3 μm.

[0052] 4.48 kg of ferrous sulfate heptahydrate, 0.314 kg of copper sulfate pentahydrate, and 0.031 kg of ammonium molybdate were weighed and dissolved in deionized water to prepare a first metal ion solution. The total metal ion concentration in the first metal ion solution was 3 mol / L. Ammonium molybdate was dissolved in deionized water to prepare a second metal ion solution. The metal ion concentration in the second metal ion solution was 1 mol / L.

[0053] In addition, according to the stoichiometric ratio, 5% excess sodium hydroxide is weighed, that is, 5% more sodium hydroxide is weighed on the basis of the amount of sodium hydroxide required by the stoichiometric ratio, and the sodium hydroxide is dissolved in deionized water to prepare a sodium hydroxide solution with a concentration of 4 mol / L.

[0054] The first metal ion solution was heated to 70° C., and the second metal ion solution was slowly added to the first metal ion solution at a stirring speed of 100 r / min, and then the sodium hydroxide aqueous solution was slowly added. The stirring was continued for 30 minutes to allow the reaction to complete and generate a precipitate.

[0055] The precipitate was filtered, washed with deionized water several times, and then dried at 160° C. for 6 h to obtain the precursor.

[0056] Under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, the precursor was reduced at 660°C for 4 hours and then at 720°C for 2 hours. It was then crushed and sieved to obtain an iron-copper-molybdenum alloy powder.

[0057] The iron-copper-molybdenum alloy powder was placed into a steel mold with a size of 50*10*5mm and hot-pressed and sintered for 60 minutes at 30MPa and 850°C in a hydrogen atmosphere sintering furnace to obtain a diamond sintered body.

[0058] After testing, the diamond sintered body has a Rockwell hardness of HRB108, a bending strength of 1357MPa, and a density of 98.8%.

[0059] Example 3

[0060] An iron-copper-molybdenum alloy powder comprises the following components in weight percentage: 78.7% iron, 20% copper, 1% molybdenum, 0.2% oxygen, and the balance being inevitable impurities, and has a Fisher grain size of 2.7 μm.

[0061] 3.918 kg of ferrous sulfate heptahydrate, 0.786 kg of copper sulfate pentahydrate, and 0.02 kg of ammonium molybdate were weighed and dissolved in deionized water to prepare a first metal ion solution. The total metal ion concentration in the first metal ion solution was 2 mol / L. Ammonium molybdate was dissolved in deionized water to prepare a second metal ion solution. The metal ion concentration in the second metal ion solution was 2 mol / L.

[0062] In addition, according to the stoichiometric ratio, 5% excess sodium hydroxide is weighed, that is, 5% more sodium hydroxide is weighed on the basis of the amount of sodium hydroxide required by the stoichiometric ratio, and the sodium hydroxide is dissolved in deionized water to prepare a sodium hydroxide solution with a concentration of 3 mol / L.

[0063] The first metal ion solution was heated to 60° C., and the second metal ion solution was slowly added to the first metal ion solution at a stirring speed of 100 r / min, and then the sodium hydroxide aqueous solution was slowly added. The stirring was continued for 30 minutes to allow the reaction to complete and generate a precipitate.

[0064] The precipitate was filtered, washed with deionized water several times, and then dried at 120° C. for 6 h to obtain the precursor.

[0065] Under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, the precursor was reduced at 680°C for 4.5 hours and then at 750°C for 2.5 hours. It was then crushed and sieved to obtain an iron-copper-molybdenum alloy powder.

[0066] The iron-copper-molybdenum alloy powder was placed into a steel mold with a size of 50*10*5mm and hot-pressed and sintered for 60 minutes at 30MPa and 850°C in a hydrogen atmosphere sintering furnace to obtain a diamond sintered body.

[0067] After testing, the diamond sintered body has a Rockwell hardness of HRB104, a bending strength of 1342MPa, and a density of 98.3%.

[0068] Example 4

[0069] An iron-copper-molybdenum alloy powder comprises the following components in weight percentage: 81.5% iron, 15% copper, 3% molybdenum, 0.4% oxygen, and the balance being inevitable impurities, and has a Fisher grain size of 1.5 μm.

[0070] 4.057 kg of ferrous sulfate heptahydrate, 0.589 kg of copper sulfate pentahydrate, and 0.061 kg of ammonium molybdate were weighed and dissolved in deionized water to prepare a first metal ion solution. The total metal ion concentration in the first metal ion solution was 1 mol / L. Ammonium molybdate was dissolved in deionized water to prepare a second metal ion solution. The metal ion concentration in the second metal ion solution was 2 mol / L.

[0071] In addition, according to the stoichiometric ratio, 5% excess sodium hydroxide is weighed, that is, 5% more sodium hydroxide is weighed on the basis of the amount of sodium hydroxide required by the stoichiometric ratio, and the sodium hydroxide is dissolved in deionized water to prepare a sodium hydroxide solution with a concentration of 2 mol / L.

[0072] The first metal ion solution was heated to 50° C., and the second metal ion solution was slowly added to the first metal ion solution at a stirring speed of 100 r / min, and then the sodium hydroxide aqueous solution was slowly added. The stirring was continued for 30 minutes to allow the reaction to complete and generate a precipitate.

[0073] The precipitate was filtered, washed with deionized water several times, and then dried at 120° C. for 6 h to obtain the precursor.

[0074] Under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, the precursor was reduced at 650°C for 3.5 hours and then at 700°C for 1.5 hours. It was then crushed and sieved to obtain an iron-copper-molybdenum alloy powder.

[0075] The iron-copper-molybdenum alloy powder was placed into a steel mold with a size of 50*10*5mm and hot-pressed and sintered for 60 minutes at 30MPa and 850°C in a hydrogen atmosphere sintering furnace to obtain a diamond sintered body.

[0076] After testing, the diamond sintered body has a Rockwell hardness of HRB105, a bending strength of 1338MPa, and a density of 98.5%.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 1 is that the precursor is reduced at 750° C. for 5 h under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, and then crushed and sieved to obtain an iron-copper-molybdenum alloy powder.

[0079] After testing, the diamond sintered body has a Rockwell hardness of HRB93, a bending strength of 1084MPa, and a density of 92.4%.

[0080] Comparative Example 2

[0081] The difference between this comparative example and Example 1 is that the precursor is reduced at 650° C. for 5 h under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, and then crushed and sieved to obtain an iron-copper-molybdenum alloy powder.

[0082] After testing, the diamond sintered body has a Rockwell hardness of HRB98, a bending strength of 1254MPa, and a density of 95.3%.

[0083] Comparative Example 3

[0084] This comparative example differs from Example 1 in that, under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, the precursor is reduced at 650° C. for 1.5 h and then at 700° C. for 3.5 h. Subsequently, the precursor is crushed and sieved to obtain an iron-copper-molybdenum alloy powder.

[0085] After testing, the diamond sintered body has a Rockwell hardness of HRB96, a bending strength of 1217MPa, and a density of 94.1%.

[0086] Comparative Example 4

[0087] This comparative example differs from Example 1 in that, under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, the precursor is reduced at 600° C. for 3.5 h and then at 850° C. for 1.5 h. Subsequently, the precursor is crushed and sieved to obtain an iron-copper-molybdenum alloy powder.

[0088] After testing, the diamond sintered body has a Rockwell hardness of HRB94, a bending strength of 1132MPa, and a density of 92.6%.

[0089] In Comparative Examples 1 and 3, the precursors were reduced at high temperatures for extended periods of time, resulting in coarsening of the grain size and poor density. In Comparative Example 2, the reduction was carried out at lower temperatures for extended periods of time, leading to high oxygen content and, in turn, poor density. In Comparative Example 4, the temperature exceeded the temperature range selected by the present invention, resulting in not only high oxygen content but also coarsening of the grain size, thus reducing density.

[0090] Compared with comparative examples 1-4, the diamond sintered body prepared using the iron-copper-molybdenum alloy powder in the embodiment of the present invention has higher bending strength and hardness, and good density, indicating that by preparing the iron-copper-molybdenum alloy powder according to the ratio and method disclosed in the present invention, an alloy powder with high strength, high hardness and good sintering performance can be obtained, which meets the industry's high quality requirements for alloy powder.

[0091] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0092] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An iron-copper-molybdenum alloy powder, characterized in that: At least include the following components in weight percentage: iron 75%-90%, copper 8%-20%, molybdenum 1%-5%; The iron-copper-molybdenum alloy powder is prepared by co-precipitating a soluble salt solution of iron, copper and molybdenum with an alkali, drying the co-precipitate to form an oxide precursor, and then reducing the precursor. The reduction operation is first carried out at 650°C-680°C for 3.5h-4.5h, and then at 700°C-750°C for 1.5h-2.5h.

2. The iron-copper-molybdenum alloy powder according to claim 1, characterized in that The Fe-Cu-Mo alloy powder has a Fisher particle size of less than 3 μm.

3. A method for preparing iron-copper-molybdenum alloy powder, characterized in that: The steps include: Dissolving a soluble salt of iron and a soluble salt of copper in water to prepare a first metal ion solution, and dissolving a soluble salt of molybdenum in water to prepare a second metal ion solution; Heat the first metal ion solution to 50°C-70°C, add the second metal ion solution, then add alkali, and stir to react to form a coprecipitate; The coprecipitate is filtered, washed, and dried to obtain a precursor; The precursor is first reduced at 650° C.-680° C. for 3.5 h-4.5 h, and then reduced at 700° C.-750° C. for 1.5 h-2.5 h to obtain iron-copper-molybdenum alloy powder.

4. The method for preparing the iron-copper-molybdenum alloy powder according to claim 3, wherein In the first metal ion solution, the total metal ion concentration is 1-3 mol / L; in the second metal ion solution, the metal ion concentration is 1-2 mol / L.

5. The method for preparing the iron-copper-molybdenum alloy powder according to claim 3, wherein: The drying temperature is 120° C. to 160° C., and the drying time is 6 hours to 8 hours.

6. The method for preparing the iron-copper-molybdenum alloy powder according to claim 3, wherein: The reduction is carried out under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s to 0.05 m / s.

7. The method for preparing the iron-copper-molybdenum alloy powder according to claim 3, wherein: The soluble iron salt is at least one of iron sulfate, nitrate and chloride.

8. The method for preparing the iron-copper-molybdenum alloy powder according to claim 3, wherein: The soluble salt of copper is at least one of copper sulfate, nitrate and chloride.

9. The method for preparing the iron-copper-molybdenum alloy powder according to claim 3, wherein: The soluble salt of molybdenum is ammonium molybdate.

10. A diamond sintered body, characterized in that: The invention is prepared by at least using the iron-copper-molybdenum alloy powder according to any one of claims 1-2 or the iron-copper-molybdenum alloy powder prepared by the preparation method according to any one of claims 3-9.