Iron-copper-molybdenum alloy powder, method for producing the same, and diamond sinter

Abstract

The application discloses a kind of iron copper molybdenum alloy powder, at least including the following weight percentage components: iron 75%-90%, copper 8%-20%, molybdenum 1%-5%;The iron copper molybdenum alloy powder is obtained by co-precipitation of soluble salt aqueous solution of iron, copper and molybdenum with alkali, drying to generate oxide precursor, and then reducing;Wherein, the reduction operation is first reduced at 650-680 DEG C for 3.5-4.5 h, and then reduced at 700-750 DEG C for 1.5-2.5 h.The iron copper molybdenum alloy powder prepared by optimizing component ratio and preparation process has excellent hardness, and is suitable for the production of various sintered diamond tools.The sintered body prepared has excellent bending strength, wide market prospect and significant application value.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of alloy powder, and particularly relates to an iron-copper-molybdenum alloy powder, a preparation method thereof and a diamond sintered body. BACKGROUND

[0002] The diamond tool refers to a tool product with a certain shape, performance and purpose, which is made of diamond particles or powder as the main cutting and grinding material and other auxiliary materials. The application field of the diamond tool is very wide, such as building material and stone processing, mechanical processing, geological exploration and mineral exploitation, etc. The application of the diamond tool in the above fields mainly depends on its high hardness, high wear resistance and other performances, which are greatly dependent on the matrix material of the diamond tool.

[0003] In the prior art, the commonly used matrix materials include iron-based alloy and copper-based alloy, but the strength, hardness, wear resistance and sintering performance thereof are difficult to simultaneously reach the best state, which limits the performance improvement of the diamond tool. Therefore, it is an urgent need of the industry development to develop an alloy powder with high strength, high hardness and good sintering performance.

[0004] The information disclosed in this BACKGROUND section is only intended to increase an understanding of the general background of the application and is not intended to be a recognition or any form of suggestion that this information constitutes prior art. SUMMARY

[0005] The application aims 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 tools. The produced sintered diamond tools have excellent bending strength and can significantly improve the service life and working performance of the tools.

[0006] In order to achieve the above-mentioned purpose, the technical scheme provided by one specific embodiment of the application is as follows:

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

[0008] The iron-copper-molybdenum alloy powder is prepared by co-precipitating soluble salt aqueous solutions of iron, copper and molybdenum with alkali, drying the co-precipitate to generate an oxide precursor, and then reducing the oxide precursor; wherein the reduction operation is first reduced at 650-680 DEG C for 3.5-4.5 h, and then reduced at 700-750 DEG C for 1.5-2.5 h.

[0009] In one or more embodiments of the application, the Feishan particle size of the iron-copper-molybdenum alloy powder is less than 3 microns.

[0010] Another specific embodiment of the present application provides the technical scheme as follows:

[0011] A preparation method of an iron-copper-molybdenum alloy powder comprises the following steps:

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

[0013] Heat the first metal ion solution to 50-70 DEG C, add the second metal ion solution, then add alkali, and stir to generate coprecipitation;

[0014] Filter, wash and dry the coprecipitation to obtain a precursor;

[0015] Reduce the precursor at 650-680 DEG C for 3.5-4.5 h, and then reduce it at 700-750 DEG C for 1.5-2.5 h to obtain the iron-copper-molybdenum alloy powder.

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

[0017] In one or more embodiments of the present application, the drying temperature is 120-160 DEG C, and the time is 6-8 h.

[0018] In one or more embodiments of the present application, the reduction is performed in a hydrogen atmosphere, and the hydrogen volume flux is 0.03-0.05 m / s.

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

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

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

[0022] Another specific embodiment of the present application provides the technical scheme as follows:

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

[0024] Compared with the prior art, the iron-copper-molybdenum alloy powder has high hardness and high strength, improves the cutting and wear resistance of the diamond tool, has good sintering performance, is suitable for industrial large-scale production, and is widely applied to the production of sintered diamond tools such as saw blades, drill bits and wire saws. DETAILED DESCRIPTION

[0025] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should belong to the protection scope of the present application.

[0026] The specific embodiment of the present application provides an iron-copper-molybdenum alloy powder, which at least comprises the following weight percentage components: iron 75%-90%, copper 8%-20%, and molybdenum 1%-5%. The iron-copper-molybdenum alloy powder is prepared by co-precipitating a water-soluble salt solution of iron, copper and molybdenum with an alkali, drying the co-precipitate to generate an oxide precursor, and then reducing the oxide precursor. The reduction operation is first reduced at 650-680 DEG C for 3.5-4.5 hours, and then reduced at 700-750 DEG C for 1.5-2.5 hours.

[0027] Specifically, iron is the main component of the alloy powder, and by controlling the content, the alloy can have high strength and hardness. If the content is too high, it may have a negative impact on subsequent sintering, affect the density of the alloy, and thus may reduce the strength of the alloy. Copper can strengthen the alloy and improve the strength and strength of the alloy. Suitable content can significantly improve the mechanical properties of the alloy, but too high content may cause residual pores in the alloy, which may reduce the mechanical properties of the alloy. Molybdenum can promote the densification of the alloy and improve the microstructure of the alloy during sintering, thereby improving the mechanical properties of the alloy. However, too high content of molybdenum may increase the sintering difficulty and thus reduce the mechanical properties of the alloy.

[0028] The iron-copper-molybdenum alloy powder is prepared by the co-precipitation and co-reduction method, so that the iron element, the copper element and the molybdenum element can be uniformly distributed in the alloy powder, and the mechanical properties of the alloy are improved. More importantly, in the reduction process, different temperatures are used for reduction, first reduction at a lower temperature to remove most of the oxygen and water vapor, and then reduction at a higher temperature to remove the remaining oxygen and promote the diffusion alloying between elements at high temperature. Moreover, the reduction time is relatively short at high temperature, which can reduce the grain growth of the powder. The finer the grain, the more it helps to improve the strength and hardness of the alloy, and it also helps to improve the sintering density, so that the finally obtained alloy has excellent mechanical properties.

[0029] Further, the Fe's particle size of the iron-copper-molybdenum alloy powder is less than 3 μm.

[0030] Specifically, the smaller Fe's particle size helps to improve the sintering density, so that the strength and hardness of the alloy can be improved.

[0031] Another specific embodiment of the present application provides a preparation method of an 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 a sulfate, a nitrate and a chloride of iron, the soluble salt of copper is at least one of a sulfate, a nitrate and a chloride of copper, and the soluble salt of molybdenum is ammonium molybdate. In the first metal ion solution, the total concentration of metal ions is 1-3 mol / L, and in the second metal ion solution, the concentration of metal ions is 1-2 mol / L.

[0034] Step 2, heating the first metal ion solution to 50-70℃, adding the second metal ion solution, then adding a base, and stirring to generate a co-precipitate.

[0035] Specifically, the second metal ion is mixed with the first metal ion solution in a stoichiometric ratio, and a corresponding co-precipitate is generated by reaction with a base. The base is at least one of sodium hydroxide, ammonia and sodium carbonate.

[0036] Step 3, filtering, washing and drying the co-precipitate to obtain a precursor.

[0037] Specifically, the co-precipitate is filtered, washed with water, and dried at 120-160℃ for 6-8h, so that the co-precipitate generates an oxide precursor by drying.

[0038] Step 4: the precursor is reduced at 650-680℃ for 3.5-4.5h and then at 700-750℃ for 1.5-2.5h to obtain the iron-copper-molybdenum alloy powder.

[0039] Specifically, the reduction is carried out in a hydrogen atmosphere, and the hydrogen volume flux is 0.03-0.05m / s. During the reduction, the oxygen element contained in the precursor generates water, which escapes from the system in the form of water vapor. By reducing at a lower temperature first, the external oxygen element in the precursor is removed first, and then by reducing at a higher temperature, the internal oxygen element in the precursor is completely removed. At this time, the remaining oxygen element escapes from the system in the form of water vapor, and since the amount is small, the impact of the water vapor escaping on the diffusion and alloying between elements is small, allowing the elements to diffuse and alloy normally. If the reduction is directly carried out at a higher temperature, the water vapor escapes from the system at a faster speed, which may affect the diffusion between elements. Moreover, long-time reduction at a higher temperature may cause the powder grains to grow, thereby reducing the strength and hardness of the alloy.

[0040] The application will be further described in detail below with reference to specific examples.

[0041] Example 1

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

[0043] Take 3.734kg of ferrous sulfate heptahydrate, 0.77kg of copper sulfate pentahydrate and 0.102kg of ammonium molybdate, dissolve the ferrous sulfate heptahydrate and copper sulfate pentahydrate in deionized water to prepare a first metal ion solution, and the total concentration of metal ions in the first metal ion solution is 1mol / L. Dissolve the ammonium molybdate in deionized water to prepare a second metal ion solution, and the concentration of metal ions in the second metal ion solution is 2mol / L.

[0044] In addition, according to the stoichiometric ratio, take an excess of 5% of sodium hydroxide, i.e. take an additional 5% of sodium hydroxide based on the amount of sodium hydroxide required by the stoichiometric ratio, dissolve the sodium hydroxide in deionized water to prepare a sodium hydroxide solution with a concentration of 2mol / L.

[0045] Heat the first metal ion solution to 50℃, slowly add the second metal ion solution to the first metal ion solution under a stirring speed of 100r / min, and then slowly add the sodium hydroxide solution, and continue stirring for 30min to completely generate precipitate.

[0046] Filter the precipitate and wash it with deionized water several times, and then dry it at 120℃ for 6h to obtain the precursor.

[0047] The precursor is reduced at 650℃ for 3.5h and at 700℃ for 1.5h under hydrogen atmosphere with a hydrogen volume flux of 0.03m / s. Then, crushing and screening are performed to obtain the iron-copper-molybdenum alloy powder.

[0048] The iron-copper-molybdenum alloy powder is loaded into a steel mold with a size of 50*10*5mm, and hot-press sintering is performed at 30MPa and 850℃ for 60min in a hydrogen atmosphere sintering furnace to obtain the diamond sintered body.

[0049] 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 includes the following components by weight percentage: iron 90%, copper 8%, molybdenum 1.5%, oxygen 0.4%, and the balance being inevitable impurities, and has a Fisher particle size of 2.3μm.

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

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

[0054] The first metal ion solution is heated to 70℃, the second metal ion solution is slowly added to the first metal ion solution at a stirring speed of 100r / min, and then the sodium hydroxide solution is slowly added, and stirring is continued for 30min to completely generate precipitate.

[0055] The precipitate is filtered and washed with deionized water for multiple times, and then dried at 160℃ for 6h to obtain the precursor.

[0056] The precursor is reduced at 660℃ for 4h and at 720℃ for 2h under hydrogen atmosphere with a hydrogen volume flux of 0.03m / s. Then, crushing and screening are performed to obtain the iron-copper-molybdenum alloy powder.

[0057] The iron-copper-molybdenum alloy powder is loaded into a steel mold with a size of 50*10*5mm, and hot-press sintering is performed in a hydrogen atmosphere sintering furnace at 30MPa and 850℃ for 60min to obtain a diamond sintered body.

[0058] 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 includes the following components by weight percentage: iron 78.7%, copper 20%, molybdenum 1%, oxygen 0.2%, and the balance being inevitable impurities, and has a Fisher particle size of 2.7μm.

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

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

[0063] The first metal ion solution is heated to 60℃, the second metal ion solution is slowly added to the first metal ion solution at a stirring speed of 100r / min, and then the sodium hydroxide solution is slowly added, and the stirring is continued for 30min to completely generate precipitates.

[0064] The precipitates are filtered and washed with deionized water for multiple times, and then dried at 120℃ for 6h to obtain a precursor.

[0065] The precursor is reduced at 680℃ for 4.5h and then at 750℃ for 2.5h under a hydrogen atmosphere with a hydrogen gas volume flux of 0.03m / s, and then broken and sieved to obtain an iron-copper-molybdenum alloy powder.

[0066] The iron-copper-molybdenum alloy powder is loaded into a steel mold with a size of 50*10*5mm, and hot-press sintering is performed in a hydrogen atmosphere sintering furnace at 30MPa and 850℃ for 60min to obtain a diamond sintered body.

[0067] 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 comprising the following components by weight percentage: iron 81.5%, copper 15%, molybdenum 3%, oxygen 0.4%, and the balance being inevitable impurities, and having a Fisher particle 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 are weighed out, the ferrous sulfate heptahydrate and the copper sulfate pentahydrate are dissolved in deionized water to prepare a first metal ion solution, and in the first metal ion solution, the total concentration of metal ions is 1 mol / L. The ammonium molybdate is dissolved in deionized water to prepare a second metal ion solution, and in the second metal ion solution, the concentration of metal ions is 2 mol / L.

[0071] In addition, according to the stoichiometric ratio, an excess of 5% of sodium hydroxide is weighed out, i.e. 5% more by mass of sodium hydroxide is weighed out in addition to the amount of sodium hydroxide required according to 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 is heated to 50°C, and the second metal ion solution is slowly added to the first metal ion solution under stirring at a speed of 100 r / min, and then the aqueous sodium hydroxide solution is slowly added, and stirring is continued for 30 min to completely generate precipitates.

[0073] The precipitates are filtered and washed with deionized water for multiple times, and then dried at 120°C for 6 h to obtain a precursor.

[0074] Under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s, the precursor is reduced at 650°C for 3.5 h and then at 700°C for 1.5 h. Subsequently, crushing and sieving are performed to obtain an iron-copper-molybdenum alloy powder.

[0075] The iron-copper-molybdenum alloy powder is loaded into a steel mold with dimensions of 50*10*5 mm, and hot-press sintering is performed in a hydrogen atmosphere sintering furnace at 30 MPa and 850°C for 60 min to obtain a diamond sintered body.

[0076] It is detected that the diamond sintered body has a Rockwell hardness HRB105, a bending strength of 1338 MPa, and a density of 98.5%.

[0077] Comparative Example 1

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

[0079] The diamond sintered body has a Rockwell hardness HRB of 93, a bending strength of 1084 MPa, and a density of 92.4%.

[0080] Comparative Example 2

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

[0082] The diamond sintered body has a Rockwell hardness HRB of 98, a bending strength of 1254 MPa, and a density of 95.3%.

[0083] Comparative Example 3

[0084] The difference between the present comparative example and Example 1 is that the precursor is reduced at 650 DEG C for 1.5 h and then at 700 DEG C for 3.5 h under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s. Then, the precursor is crushed and sieved to obtain the iron-copper-molybdenum alloy powder.

[0085] The diamond sintered body has a Rockwell hardness HRB of 96, a bending strength of 1217 MPa, and a density of 94.1%.

[0086] Comparative Example 4

[0087] The difference between the present comparative example and Example 1 is that the precursor is reduced at 600 DEG C for 3.5 h and then at 850 DEG C for 1.5 h under a hydrogen atmosphere with a hydrogen volume flux of 0.03 m / s. Then, the precursor is crushed and sieved to obtain the iron-copper-molybdenum alloy powder.

[0088] The diamond sintered body has a Rockwell hardness HRB of 94, a bending strength of 1132 MPa, and a density of 92.6%.

[0089] The precursor in Comparative Examples 1 and 3 is reduced at a high temperature for a long time, so the grain size is coarse, resulting in poor density. In Comparative Example 2, the precursor is reduced at a lower temperature for a long time, resulting in high oxygen content, which also leads to poor density. In Comparative Example 4, the temperature exceeds the temperature range selected in the present application, resulting in not only high oxygen content but also coarse grain size, thus leading to low density.

[0090] Compared with Comparative Examples 1-4, the diamond sintered body prepared from the iron-copper-molybdenum alloy powder in the present application has higher bending strength and hardness and good density, indicating that the iron-copper-molybdenum alloy powder prepared according to the ratio and method disclosed in the present application can obtain an alloy powder with high strength, high hardness and good sintering performance, meeting the high quality requirements of the industry development for alloy powder.

[0091] It will be obvious to a person skilled in the art that the application is not limited to the details of the above-described exemplary embodiments, but that the application can be implemented in other embodiments without departing from the scope of the application. The embodiments are therefore to be seen as exemplary and in no way restrictive, the scope of the application being defined by the claims below rather than by the above description, and all variations falling within the meaning and range of equivalency of the essential characteristics of the claims are therefore intended to be embraced therein.

[0092] Furthermore, it should be understood that although the description is made according to embodiments, not every embodiment contains only one independent technical solution, and the description is made in this way only for the sake of clarity, and a person skilled in the art should consider the description as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by a person skilled in the art.

Claims

1. A method of producing an iron-copper-molybdenum alloy powder, characterized by, The method comprises the following steps: dissolving soluble salt of iron and soluble salt of copper in water to form a first metal ion solution, and dissolving soluble salt of molybdenum in water to form a second metal ion solution; heating the first metal ion solution to 50-70℃, adding the second metal ion solution, and then adding alkali to generate coprecipitation by stirring and reacting; filtering, washing and drying the coprecipitation to obtain a precursor; reducing the precursor at 650-680℃ for 3.5-4.5h, and then reducing the precursor at 700-750℃ for 1.5-2.5h to obtain the iron-copper-molybdenum alloy powder; the iron-copper-molybdenum alloy powder comprises the following components by weight percentage: 75-90% of iron, 8-20% of copper and 1-5% of molybdenum; the total concentration of metal ions in the first metal ion solution is 1-3mol / L, and the concentration of metal ions in the second metal ion solution is 1-2mol / L.

2. The method of producing the ferro-copper-molybdenum alloy powder according to claim 1, characterized by, the drying temperature is 120-160℃, and the drying time is 6-8h.

3. The method of producing the ferro-copper-molybdenum alloy powder according to claim 1, characterized by, the reduction is performed in a hydrogen atmosphere, and the hydrogen volume flux is 0.03-0.05m / s.

4. The method of producing the ferro-copper-molybdenum alloy powder according to claim 1, characterized by, the soluble salt of iron is at least one of sulfate, nitrate and chloride of iron.

5. The method of claim 1, wherein the iron-copper-molybdenum alloy powder is prepared by the steps of: the soluble salt of copper is at least one of sulfate, nitrate and chloride of copper. ​ 6. The method of producing the ferro-copper-molybdenum alloy powder according to claim 1, characterized by, the soluble salt of molybdenum is ammonium molybdate.

7. The method of claim 1, wherein the iron-copper-molybdenum alloy powder is prepared by the steps of: preparing a molten iron-copper-molybdenum alloy; and atomizing the molten iron-copper-molybdenum alloy. the Feeder's particle size of the iron-copper-molybdenum alloy powder is less than 3μm.

8. A diamond sinter, characterized by, at least the iron-copper-molybdenum alloy powder prepared by the method of any one of claims 1-7 is used.