Cobalt powder for ceramic tools and method for producing the same

Abstract

The application further provides a cobalt powder for ceramic tools and a preparation method thereof, which belongs to the technical field of metal powder preparation and comprises the following components in parts by weight: 85-90 parts of cobalt powder raw material, 1-5 parts of stabilizer, 0.5-2 parts of dispersant and 3-8 parts of metal oxide. The application comprises the following steps: S1, preparing a mixture; S2, preparing crude sponge cobalt; and S3, preparing cobalt powder. The addition of metal oxide enables the product to be mixed with the oxides of zirconium or chromium required by the ceramic tools in advance during preparation, so that the content range of each component can be further optimized in the later preparation of the ceramic tools, the preparation time is shortened, the cost of preparing the ceramic tools is reduced, the ball milling time of the ceramic powder mixture is reduced, the anti-impact strength and wear resistance of the ceramic tools are enhanced, the appearance distribution is uniform, the product quality is stable, one-step reduction is achieved, the production efficiency is high, the hydrogen flow is reduced, energy is saved, emission is reduced, and cost is saved.

Description

Technical Field

[0001] This invention relates to the field of metal powder preparation technology, and more specifically, to cobalt powder for ceramic tools and its preparation method. Background Technology

[0002] Current methods for preparing cobalt powder for ceramic tools involve a two-step process of inert gas decomposition and hydrogen reduction, which is time-consuming and unsuitable for mass production. Other methods, with small raw material loadings, require large amounts of hydrogen reduction, resulting in excessive energy consumption and low safety. Furthermore, existing technologies for preparing ceramic tools involve a wide range of subsequent component contents, extending preparation time and increasing the cost of ceramic tool production. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a cobalt powder for ceramic tools and a method for preparing the same.

[0004] This invention provides a cobalt powder for ceramic tools, comprising the following components in parts by weight:

[0005]

[0006] In some embodiments, the cobalt powder raw material is selected from one of cobalt oxalate, cobalt carbonate, and cobalt tetroxide.

[0007] In some embodiments, the stabilizer is selected from one or more of calcium stearate, lithium stearate, and dibutyltin dilaurate.

[0008] In some embodiments, the dispersant is selected from one or more of polyacrylic acid, oleic acid, and fish oil.

[0009] In some embodiments, the metal oxide is selected from one or more of zirconium dioxide, chromium trioxide, chromium trioxide, and chromium dioxide.

[0010] This invention also provides a method for preparing cobalt powder for ceramic tools, comprising the following steps:

[0011] S1. Preparation of the mixture: Using cobalt powder as the main raw material, add stabilizer, dispersant and metal oxide, ball mill and batch, and dry in an oven at a low temperature of 30℃-45℃ to obtain the mixture;

[0012] S2. Preparation of crude cobalt sponge: The mixture prepared in step S1 is loaded into a boat tray, and then subjected to hydrogen deoxygenation reduction, with the temperature raised to 400-550℃ and the hydrogen flow rate 4-6m³ / h. 3 After reduction for 8-10 hours and cooling, crude cobalt sponge is obtained.

[0013] S3. Preparation of cobalt powder: The crude sponge cobalt prepared in step S2 is first subjected to mechanical or airflow crushing, and then ultrasonic vibration classification. The final cobalt powder has a Fisher particle size of 0.3-0.5 μm and an oxygen content of 0.3-0.45%.

[0014] In some embodiments, in step S1, the weight parts of each component in the mixture are as follows: 85-90 parts of cobalt powder raw material, 1-5 parts of stabilizer, 0.5-2 parts of dispersant, and 3-8 parts of metal oxide.

[0015] In some embodiments, the cobalt powder raw material is selected from cobalt oxalate, cobalt carbonate, and cobalt tetroxide. The stabilizer is selected from one or more of calcium stearate, lithium stearate, and dibutyltin dilaurate. The dispersant is selected from one or more of polyacrylic acid, oleic acid, and fish oil.

[0016] In some implementations, in step S2,

[0017] When the cobalt powder raw material is cobalt oxalate, the temperature is raised to 450-500℃;

[0018] When the cobalt powder raw material is cobalt carbonate, the temperature is raised to 400-480℃;

[0019] When the cobalt powder raw material is cobalt tetroxide, the temperature is raised to 450-550℃.

[0020] In some embodiments, S3, preparing cobalt powder: the crude sponge cobalt is first crushed by an air jet mill at a frequency of 50-60Hz, then sieved by an ultrasonic vibrating screen, and finally dried and batch-processed to obtain cobalt powder.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The addition of metal oxides in this invention allows the product to be mixed and contacted with zirconium or chromium oxides, which are required components for ceramic tools, in advance during the preparation process. This can further optimize the content range of each component in the later preparation of ceramic tools, shorten the preparation time, and reduce the cost of preparing ceramic tools.

[0023] (2) This invention prepares ultrafine cobalt powder with an average particle size of 0.3-0.5 μm and an oxygen content of 0.3-0.45% through a preparation method. This can significantly reduce the ball milling time of ceramic powder mixtures by 25-45 min. The cobalt powder prepared by adding metal oxides can increase the impact resistance of ceramic tools by 0.03-0.08 J / cm. 2 Furthermore, it increases the wear resistance speed by 200-600 revolutions;

[0024] (3) The present invention reduces the raw materials in one step after processing, resulting in high production efficiency, reduced hydrogen flow, energy saving and emission reduction, cost saving, and the final product obtained is a spherical sponge with uniform morphology and stable product quality. Attached Figure Description

[0025] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1 This is a flowchart of the method for preparing cobalt powder for ceramic tools according to the present invention. Detailed Implementation

[0027] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0028] Example 1

[0029] This invention provides a cobalt powder for ceramic tools and its preparation method, comprising the following components in parts by weight: 85 parts cobalt oxalate, 5 parts calcium stearate, 0.5 parts fish oil, and 3 parts chromium trioxide.

[0030] Its specific preparation method includes the following steps:

[0031] S1. Preparation of mixture: Using 85 parts of cobalt oxalate as the main component, add 5 parts of calcium stearate, 0.5 parts of fish oil and 3 parts of chromium trioxide, ball mill for 2 hours, and then dry in an oven at low temperature. The oven temperature is set to 30℃ and dried for 2 hours to obtain the mixture.

[0032] S2. Preparation of crude cobalt sponge: The mixture is loaded into boat trays, 4 kg per boat, and then subjected to hydrogen deoxygenation reduction, heated to 465℃, with a hydrogen flow rate of 4.2 m³ / h. 3 After reduction for 8.5 hours and cooling, crude sponge cobalt is obtained.

[0033] S3. Preparation of cobalt powder: The crude sponge cobalt is first crushed by an air jet mill at a frequency of 52Hz, then sieved by an ultrasonic vibrating screen with a mesh size of 400 mesh, and finally dried and batch processed to obtain cobalt powder.

[0034] The cobalt powder obtained in step S3 above has a Fisher particle size of 0.33 μm, an oxygen content of 0.42%, a uniform morphology distribution, is not easily sintered during reduction, and has a high yield.

[0035] Example 2

[0036] This invention provides a cobalt powder for ceramic tools and its preparation method, comprising the following components in parts by weight: 90 parts cobalt carbonate, 5 parts calcium stearate, 0.5 parts oleic acid, and 5 parts chromium trioxide.

[0037] Its specific preparation method includes the following steps:

[0038] S1. Preparation of mixture: Using 90 parts of cobalt carbonate as the main component, add 5 parts of calcium stearate, 0.5 parts of oleic acid and 5 parts of chromium trioxide, ball mill for 2 hours, and then dry in an oven at low temperature. The oven temperature is set to 35℃ and dried for 2 hours to obtain the mixture.

[0039] S2. Preparation of crude cobalt sponge: The mixture is loaded into boat trays, 5 kg per boat, and then subjected to hydrogen deoxygenation reduction, heated to 410℃, with a hydrogen flow rate of 5.0 m³ / kg. 3 After reducing for 9 hours and then cooling, crude cobalt sponge is obtained.

[0040] S3. Preparation of cobalt powder: The crude sponge cobalt is first crushed by an air jet mill at a frequency of 52Hz, then sieved by an ultrasonic vibrating screen with a mesh size of 400 mesh, and finally dried and batch processed to obtain cobalt powder.

[0041] The cobalt powder obtained in step S3 above has a Fisher particle size of 0.35 μm, an oxygen content of 0.45%, a uniform morphology distribution, is not easily sintered during reduction, and has a high yield.

[0042] Example 3

[0043] This invention provides a cobalt powder for ceramic tools and its preparation method, comprising the following components in parts by weight: 90 parts cobalt tetroxide, 3 parts dibutyltin dilaurate, 1 part polyacrylic acid, 1 part oleic acid, and 8 parts zirconium dioxide.

[0044] Its specific preparation method includes the following steps:

[0045] S1. Preparation of mixture: 90 parts of cobalt tetroxide as the main body, 3 parts of dibutyltin dilaurate, 1 part of polyacrylic acid, 1 part of oleic acid and 8 parts of zirconium dioxide are added and ball-milled for 2 hours, then put into an oven for low-temperature drying. The oven temperature is set to 40℃ and dried for 2 hours to obtain the mixture.

[0046] S2. Preparation of crude cobalt sponge: The mixture is loaded into boat trays, 4 kg per boat, and then subjected to hydrogen deoxygenation reduction, heated to 520℃, with a hydrogen flow rate of 5.5 m³ / h. 3 After reducing for 10 hours and then cooling, crude cobalt sponge is obtained.

[0047] S3. Preparation of cobalt powder: The crude sponge cobalt is first crushed by an air jet mill at a frequency of 52Hz, then sieved by an ultrasonic vibrating screen with a mesh size of 300, and finally dried and batch processed to obtain cobalt powder.

[0048] The cobalt powder obtained in step S3 above has a Fisher particle size of 0.49 μm, an oxygen content of 0.39%, a uniform morphology distribution, is not easily sintered during reduction, and has a high yield.

[0049] Example 4

[0050] This invention provides a cobalt powder for ceramic tools and its preparation method, comprising the following components in parts by weight: 90 parts cobalt tetroxide, 5 parts dibutyltin dilaurate, 2 parts polyacrylic acid, and 8 parts zirconium dioxide.

[0051] Its specific preparation method includes the following steps:

[0052] S1. Preparation of mixture: Using 90 parts of cobalt tetroxide as the main body, add 5 parts of dibutyltin dilaurate, 2 parts of polyacrylic acid and 8 parts of zirconium dioxide, ball mill for 2 hours, put into an oven for low-temperature drying, set the oven temperature to 45℃, and dry for 2 hours to obtain the mixture.

[0053] S2. Preparation of crude cobalt sponge: The mixture is loaded into boat trays, 6 kg per boat, and then subjected to hydrogen deoxygenation reduction, heated to 550℃, with a hydrogen flow rate of 6.0 m³ / min. 3 After reducing for 10 hours and then cooling, crude cobalt sponge is obtained.

[0054] S3. Preparation of cobalt powder: The crude sponge cobalt is first crushed by an air jet mill at a frequency of 52Hz, then sieved by an ultrasonic vibrating screen with a mesh size of 300, and finally dried and batch processed to obtain cobalt powder.

[0055] The cobalt powder obtained in step S3 above has a Fisher particle size of 0.44 μm, an oxygen content of 0.39%, a uniform morphology distribution, is not easily sintered during reduction, and has a high yield.

[0056] Example 5

[0057] This invention provides a cobalt powder for ceramic tools and its preparation method, comprising the following components in parts by weight: 85 parts cobalt tetroxide, 1 part dibutyltin dilaurate, 0.5 parts polyacrylic acid, and 3 parts zirconium dioxide.

[0058] Its specific preparation method includes the following steps:

[0059] S1. Preparation of mixture: Take 85 parts of cobalt tetroxide as the main body, add 1 part of dibutyltin dilaurate, 0.5 parts of polyacrylic acid and 3 parts of zirconium dioxide) and ball mill for 2 hours, put it into an oven for low temperature drying, set the oven temperature to 30℃, and dry for 2 hours to obtain the mixture.

[0060] S2. Preparation of crude cobalt sponge: The mixture is loaded into boat trays, 3 kg per boat, and then subjected to hydrogen deoxygenation reduction, heated to 450℃, with a hydrogen flow rate of 4.0 m³ / h. 3 After reducing for 8 hours and then cooling, crude cobalt sponge is obtained.

[0061] S3. Preparation of cobalt powder: The crude sponge cobalt is first crushed by an air jet mill at a frequency of 52Hz, then sieved by an ultrasonic vibrating screen with a mesh size of 300, and finally dried and batch processed to obtain cobalt powder.

[0062] The cobalt powder obtained in step S3 above has a Fisher particle size of 0.42 μm, an oxygen content of 0.42%, a uniform morphology distribution, is not easily sintered during reduction, and has a high yield.

[0063] Example 6

[0064] This invention provides a cobalt powder for ceramic tools and its preparation method, comprising the following components in parts by weight: 88 parts cobalt tetroxide, 3 parts dibutyltin dilaurate, 1 part oleic acid, and 5 parts zirconium dioxide.

[0065] Its specific preparation method includes the following steps:

[0066] S1. Preparation of mixture: Using 88 parts of cobalt tetroxide as the main body, add 3 parts of dibutyltin dilaurate, 1 part of oleic acid and 3 parts of zirconium dioxide (ZrO2) and ball mill for 2 hours. Then put it into an oven for low-temperature drying. The oven temperature is set to 43℃ and dried for 2 hours to obtain the mixture.

[0067] S2. Preparation of crude cobalt sponge: The mixture is loaded into boat trays, 4.5 kg per boat, and then subjected to hydrogen deoxygenation reduction, heated to 500℃, with a hydrogen flow rate of 5.0 m³ / h. 3 After reducing for 9 hours and then cooling, crude cobalt sponge is obtained.

[0068] S3. Preparation of cobalt powder: The crude sponge cobalt is first crushed by an air jet mill at a frequency of 52Hz, then sieved by an ultrasonic vibrating screen with a mesh size of 300, and finally dried and batch processed to obtain cobalt powder.

[0069] The cobalt powder obtained in step S3 above has a Fisher particle size of 0.41 μm, an oxygen content of 0.44%, a uniform morphology distribution, is not easily sintered during reduction, and has a high yield.

[0070] Example 7

[0071] This invention provides a cobalt powder for ceramic tools and its preparation method, comprising the following components in parts by weight: 87 parts cobalt tetroxide, 3 parts dibutyltin dilaurate, 1 part polyacrylic acid, and 6 parts zirconium dioxide.

[0072] Its specific preparation method includes the following steps:

[0073] S1. Preparation of mixture: Using 87 parts of cobalt tetroxide as the main body, add 3 parts of dibutyltin dilaurate, 1 part of polyacrylic acid and 6 parts of zirconium dioxide and ball mill for 2 hours, then put it into an oven for low-temperature drying. The oven temperature is set to 42℃ and dried for 2 hours to obtain the mixture.

[0074] S2. Preparation of crude cobalt sponge: The mixture is loaded into boat trays, 4 kg per boat, and then subjected to hydrogen deoxygenation reduction, heated to 510℃, with a hydrogen flow rate of 5.5 m³ / h. 3 After 10 hours of reduction and cooling, crude cobalt sponge was obtained.

[0075] S3. Preparation of cobalt powder: The crude sponge cobalt is first crushed by an air jet mill at a frequency of 52Hz, then sieved by an ultrasonic vibrating screen with a mesh size of 400 mesh, and finally dried and batch processed to obtain cobalt powder.

[0076] The cobalt powder obtained in step S3 above has a Fisher particle size of 0.32 μm, an oxygen content of 0.37%, a uniform morphology distribution, is not easily sintered during reduction, and has a high yield.

[0077] Comparative Example 1

[0078] Compared with Example 7, Comparative Example 1 adjusted the temperature in step S2 to 440°C while keeping other parameters unchanged. The resulting cobalt powder had a Fisher particle size of 0.91 μm and an oxygen content of 0.66%, which were too high.

[0079] Comparative Example 2

[0080] Compared with Example 7, Comparative Example 2 adjusted the loading amount per boat in step S2 to 8 kg, while keeping other parameters unchanged. The resulting cobalt powder had a Fisher particle size of 1.05 μm and an oxygen content of 0.41%, which was too high.

[0081] Comparative Example 3

[0082] Compared with Example 7, Comparative Example 3 changed the sieve mesh in step S3 to 100 mesh while keeping everything else unchanged. The resulting cobalt powder had a Fisher particle size of 1.1 μm and an oxygen content of 0.45%, which was too high.

[0083] Comparative Example 4

[0084] Compared with Example 7, Comparative Example 4 adjusted the metal oxide in step S1 to 2 parts, while keeping everything else unchanged. The resulting cobalt powder had a Fisher particle size of 1.02 μm and an oxygen content of 0.55%, which were too high.

[0085] Comparative Example 5

[0086] Compared with Example 7, in Comparative Example 5, the metal oxide in step S1 was adjusted to 0 parts, while other parts remained unchanged. The resulting cobalt powder had a Fisher particle size of 0.89 μm and an oxygen content of 0.69%, which were too high.

[0087] Comparative Example 6

[0088] Compared with Example 7, Comparative Example 6 adjusted the metal oxide in step S1 to 10 parts, while keeping other parts unchanged. The resulting cobalt powder had a Fisher particle size of 1.2 μm and an oxygen content of 0.52%, which were too high.

[0089] Example 1 0.33 0.42 Example 2 0.35 0.45 Example 3 0.49 0.39 Example 4 0.44 0.39 Example 5 0.42 0.42 Example 6 0.41 0.44 Example 7 0.32 0.37 Comparative Example 1 0.91 0.66 Comparative Example 2 1.05 0.41 Comparative Example 3 1.1 0.45 Comparative Example 4 1.02 0.55 Comparative Example 5 0.89 0.69 Comparative Example 6 1.2 0.52

[0090] According to the article "Impact Resistance of Ceramic Tools" by Wang Xiuying, published in the third issue (total issue 136) of "Chinese Ceramics" in 1994, the impact strength and wear resistance of ceramic tools were tested using this method. The ceramic tools prepared using this invention showed an increase in impact strength of 0.03-0.08 J / cm. 2 Furthermore, it increases the wear resistance speed by 200-600 revolutions.

[0091] In summary, compared to Example 7, Comparative Example 1 had a lower reaction temperature for the cobalt powder raw material, resulting in a higher oxygen content; Comparative Example 2 had a higher loading per boat, resulting in a higher Fisher particle size; and Comparative Example 3 had a smaller mesh size for the vibrating screen, resulting in a higher Fisher particle size. Comparative Example 4 did not add any metal oxides compared to Example 7, Comparative Example 5 added fewer metal oxides compared to Example 7, and Comparative Example 6 added more metal oxides compared to Example 7. All Comparative Examples 4-5 resulted in an increase in both oxygen content and Fisher particle size.

[0092] More specifically, Comparative Example 5 did not contain any metal oxides compared to Example 7, and the ceramic tool produced using the cobalt powder obtained in Comparative Example 5 had an impact resistance of 1.5 J / cm. 2 The wear resistance rating is 9000 revolutions. Compared to Comparative Example 5, the impact strength of the ceramic tool in Example 1 is 1.55 J / cm². 2 The wear resistance rating is 9300 revolutions. Compared to Comparative Example 5, the impact strength of the ceramic tool in Example 2 is 1.58 J / cm². 2The wear resistance rating is 9600 revolutions. Compared to Comparative Example 5, the impact strength of the ceramic tool in Example 3 is 1.53 J / cm². 2 The wear resistance rating is 9200 revolutions. Compared to Comparative Example 5, the impact strength of the ceramic tool in Example 4 is 1.57 J / cm². 2 The wear resistance rating is 9500 revolutions. Compared to Comparative Example 5, the impact strength of the ceramic tool in Example 5 is 1.56 J / cm². 2 The wear resistance rating is 9500 revolutions. Compared to Comparative Example 5, the impact strength of the ceramic tool in Example 6 is 1.54 J / cm². 2 The wear resistance rating is 9400 revolutions. Compared to Comparative Example 5, the impact strength of the ceramic tool in Example 7 is 1.55 J / cm². 2 The wear resistance rating is 9300 revolutions.

[0093] In summary, the addition of metal oxides allows the product to be mixed and contacted with zirconium or chromium oxides, the required components for ceramic tools, during pre-processing. This allows for further optimization of the content range of each component in the later stages of ceramic tool preparation, shortening the preparation time and reducing the cost of ceramic tool production. Failure to use, or exceeding or falling below the normal range of metal oxide values, will result in increased Fisher particle size and oxygen content. As can be seen from Examples 1-7 and Comparative Examples 1-6, even small changes in parameters will affect the final Fisher particle size and oxygen content of the cobalt powder. In this invention, a one-time deoxygenation with hydrogen effectively reduces the oxygen content. Combined with the use of an air jet mill and an ultrasonic vibrating screen, this effectively reduces the Fisher particle size. The stabilizer and dispersant do not participate in the reaction in this invention; they only play their basic stabilizing and dispersing roles during the reaction process, respectively. During ball milling, the addition of stabilizers, dispersants, and metal oxides effectively reduces the ball milling time of the ceramic powder mixture by 25-45 minutes.

[0094] It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

Claims

1. A method for preparing cobalt powder for ceramic tools, characterized in that, Includes the following steps: S1. Preparation of the mixture: Using cobalt powder as the main raw material, add stabilizer, dispersant and metal oxide, ball mill and batch, and dry in an oven at a low temperature of 30℃-45℃ to obtain the mixture; S2. Preparation of crude sponge cobalt: The mixture prepared in step S1 is loaded into a boat tray, and then hydrogen deoxygenation reduction is carried out. The temperature is raised to 400-550℃, the hydrogen flow rate is 4-6m³ / h, and after reduction for 8-10 hours, it is cooled to obtain crude sponge cobalt. S3. Preparation of cobalt powder: The crude sponge cobalt prepared in step S2 is first subjected to mechanical or airflow crushing, and then ultrasonic vibration classification. The final product cobalt powder has a Fisher particle size of 0.3-0.5 μm and an oxygen content of 0.3-0.45%. The metal oxide is selected from one or more of zirconium dioxide, chromium trioxide, chromium trioxide, and chromium dioxide; In step S1, the weight parts of each component in the mixture are as follows: 85-90 parts of cobalt powder raw material, 1-5 parts of stabilizer, 0.5-2 parts of dispersant, and 3-8 parts of metal oxide. The cobalt powder raw material is selected from one of cobalt oxalate, cobalt carbonate, and cobalt tetroxide; the stabilizer is selected from one or more of calcium stearate, lithium stearate, and dibutyltin dilaurate; and the dispersant is selected from one or more of polyacrylic acid, oleic acid, and fish oil.

2. The method for preparing cobalt powder for ceramic tools according to claim 1, characterized in that, In step S2, When the cobalt powder raw material is cobalt oxalate, the temperature is raised to 450-500℃; When the cobalt powder raw material is cobalt carbonate, the temperature is raised to 400-480℃; When the cobalt powder raw material is cobalt tetroxide, the temperature is raised to 450-550℃.

3. The method for preparing cobalt powder for ceramic tools according to claim 1, characterized in that, S3. Preparation of cobalt powder: The crude sponge cobalt is first crushed by an air jet mill at a frequency of 50-60Hz, then sieved by an ultrasonic vibrating screen, and finally dried and batch processed to obtain cobalt powder.

4. A cobalt powder for ceramic tools, characterized in that, It is prepared by the method for preparing cobalt powder for ceramic tools as described in any one of claims 1-3.

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