A powder metallurgy material and its preparation method

Abstract

The present invention discloses a powder metallurgy material and a preparation method thereof, belonging to the technical field of powder metallurgy. The raw materials include the following parts by weight: 0.5 - 1.1 parts of carbon nanotubes, 1.5 - 2.5 parts of copper, 1.8 - 3.2 parts of aluminum, 2.0 - 3.5 parts of nickel, 0.5 - 0.8 parts of titanium, 0.1 - 0.4 parts of pore-forming additive. Taking 100 parts as a reference, the balance is iron. Among them, the raw materials of the pore-forming additive include the following parts by weight: 30 - 50 parts of copper sulfate, 20 - 30 parts of titanium dioxide, 10 - 25 parts of silicon nitride, and 3 - 5 parts of potassium borohydride. In the technical solution of the present application, a pore-forming additive is creatively added to the iron-based powder metallurgy material. By reacting copper sulfate, titanium dioxide and silicon nitride in a reducing agent state, a porous material is generated, which can improve the porosity of the finished product in the processing of powder metallurgy materials; at the same time, combined with the billet sintering method of the present application, its hardness can also meet the ideal requirements.

Description

Technical Field

[0001] The invention relates to the technical field of powder metallurgy, and in particular to a powder metallurgy material and a preparation method thereof. Background Art

[0002] Powder metallurgy mainly refers to porous, semi-dense or fully dense materials made by powder metallurgy process. Powder metallurgy materials have unique chemical composition and physical and mechanical properties that cannot be obtained by traditional melting and casting processes, such as controllable porosity, uniform material structure, no macro segregation, and one-time molding.

[0003] In the prior art, the hardness of powder metallurgy materials is directly related to their porosity. The surface macroscopic hardness of powder metallurgy products decreases with the increase of porosity. This is because the matrix material is weakened by the pores. When measuring the hardness, the indenter presses on the metal matrix and the pores at the same time, resulting in a significant reduction in the volume resisting the indenter, thereby reducing the ability of the material surface to resist plastic deformation, and the measured hardness value is low. In general, as the porosity increases, the corresponding hardness of powder metallurgy materials will also decrease.

[0004] Therefore, how to provide a powder metallurgy material and a preparation method thereof to improve the porosity of the metal metallurgical material while ensuring the hardness requirement is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] To this end, the present invention provides a powder metallurgy material and a preparation method thereof to solve the related technical problems existing in the prior art.

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

[0007] According to a first aspect of the present invention, a powder metallurgy material is provided, comprising the following raw materials in parts by weight:

[0008] 0.5-1.1 parts of carbon nanotubes, 1.5-2.5 parts of copper, 1.8-3.2 parts of aluminum, 2.0-3.5 parts of nickel, 0.5-0.8 parts of titanium, 0.1-0.4 parts of pore-forming additives, based on 100 parts, the balance is iron.

[0009] Further, the following raw materials are included in parts by weight:

[0010] 0.8-1.0 parts of carbon nanotubes, 1.7-2.1 parts of copper, 2.2-3.1 parts of aluminum, 2.4-3.3 parts of nickel, 0.6-0.8 parts of titanium, 0.2-0.4 parts of pore-forming additives, based on 100 parts, the balance is iron.

[0011] Furthermore, the pore-forming additive comprises the following processing steps:

[0012] Among them, the raw materials include the following parts by weight: 30-50 parts of copper sulfate, 20-30 parts of titanium dioxide, 10-25 parts of silicon nitride, and 3-5 parts of potassium borohydride;

[0013] The processing steps include:

[0014] First, weigh the corresponding amounts of copper sulfate, titanium dioxide, silicon nitride, and potassium borohydride;

[0015] Secondly, put copper sulfate, titanium dioxide, and silicon nitride into deionized water, adjust the pH to 7-8 with sodium hydroxide, add potassium borohydride while stirring, control the temperature at 65-80 °C after the addition is completed, continue to stir for 1.5-4.0 h, centrifuge to collect the precipitate and wash it multiple times;

[0016] Thirdly, transfer the above precipitate to a tubular furnace, set the temperature at 130-160 °C and dry for 3-5 h, then gradually raise the temperature to 1100-1300 °C and heat for 3-12 h under argon protection;

[0017] Finally, after cooling, break up the above pore-forming additive, grind it into powder, and sieve it through a 300-mesh sieve.

[0018] Furthermore, the carbon nanotubes, copper, aluminum, nickel, titanium, and iron all pass through a 300-mesh sieve.

[0019] According to the second aspect of the present invention, a preparation method of a powder metallurgy material is provided for producing the powder metallurgy material as described above, including the following steps:

[0020] (1) Mixing: Put each raw material component of the powder metallurgy material into a mixer to make the raw materials evenly mixed;

[0021] (2) Cold pressing and forming: Add the raw materials mixed in step (1) into the mold cavity, press and form, and then demold;

[0022] (3) Sintering: Sinter and form the blank obtained by demolding in step (2) in a sintering furnace under nitrogen protection.

[0023] Furthermore, in step 1), the mixing stirring speed is 130-150 rpm, and the stirring time is 1-2 h.

[0024] Furthermore, in step 2), the cold pressing and forming pressure is 750-850 Mpa, and the cold pressing and forming holding time is 20-40 min.

[0025] Furthermore, in step 3), it includes:

[0026] Preheating stage: Preheat the blank after cold pressing and forming, the preheating temperature is 110-130 °C, and the preheating time is 20 min;

[0027] Heating stage: The heating rate is 35 - 50 °C / min. After heating to 850 °C, keep the temperature for 45 min.

[0028] Sintering stage: The heating rate is 100 °C / min. After heating to 1250 - 1320 °C, keep the temperature for 2 - 3 h.

[0029] Furthermore, in step 3), the nitrogen pressure is 0.3 - 0.5 Mpa.

[0030] According to the third aspect of the present invention, a bearing is provided, which is prepared by using the preparation method of the above powder metallurgy material.

[0031] The present invention has the following advantages:

[0032] In the technical solution of the present application, a pore-forming additive is creatively added to the iron-based powder metallurgy material. It reacts by combining copper sulfate, titanium dioxide and silicon nitride under the state of a reducing agent to generate a porous material, which can improve the porosity of the finished product during the processing of the powder metallurgy material; at the same time, combined with the blank sintering method of the present application, its hardness can also meet the ideal requirements. Specific Embodiments

[0033] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] In order to solve the problem that the porosity and hardness affect each other in the prior art, the present application creatively adds a pore-forming additive alone. Thus, while ensuring that the raw material composition processing meets the hardness requirements, the added pore-forming additive is used to increase the porosity, and the finished product achieves better technical effects.

[0035] According to the first aspect of the present invention, a powder metallurgy material is provided, which comprises the following raw materials in parts by weight:

[0036] 0.5 - 1.1 parts of carbon nanotubes, 1.5 - 2.5 parts of copper, 1.8 - 3.2 parts of aluminum, 2.0 - 3.5 parts of nickel, 0.5 - 0.8 parts of titanium, 0.1 - 0.4 parts of pore-forming additive. Based on 100 parts, the balance is iron.

[0037] Furthermore, it comprises the following raw materials in parts by weight:

[0038] 0.8 - 1.0 parts of carbon nanotubes, 1.7 - 2.1 parts of copper, 2.2 - 3.1 parts of aluminum, 2.4 - 3.3 parts of nickel, 0.6 - 0.8 parts of titanium, 0.2 - 0.4 parts of pore-forming additive, based on 100 parts, the balance being iron.

[0039] Further, the pore-forming additive includes the following processing steps:

[0040] Among them, the raw materials include the following parts by weight: 30 - 50 parts of copper sulfate, 20 - 30 parts of titanium dioxide, 10 - 25 parts of silicon nitride, and 3 - 5 parts of potassium borohydride;

[0041] The processing steps include:

[0042] First, weigh the corresponding amounts of copper sulfate, titanium dioxide, silicon nitride, and potassium borohydride;

[0043] Secondly, put copper sulfate, titanium dioxide, and silicon nitride into deionized water, adjust the pH to 7 - 8 with sodium hydroxide, add potassium borohydride while stirring, control the temperature at 65 - 80 °C after the addition is completed, continue stirring for 1.5 - 4.0 h, centrifuge to collect the precipitate and wash it repeatedly;

[0044] Thirdly, transfer the above precipitate to a tube furnace, set the temperature at 130 - 160 °C and dry for 3 - 5 h, then gradually raise the temperature to 1100 - 1300 °C and heat under argon protection for 3 - 12 h;

[0045] Finally, after cooling, break up the above pore-forming additive, grind it into powder and pass through a 300-mesh sieve.

[0046] Further, the carbon nanotubes, copper, aluminum, nickel, titanium, and iron all pass through a 300-mesh sieve.

[0047] According to the second aspect of the present invention, there is provided a preparation method of a powder metallurgy material for producing the above powder metallurgy material, including the following steps:

[0048] (1) Mixing: Put each raw material component of the powder metallurgy material into a mixer to make the raw materials evenly mixed;

[0049] (2) Cold pressing and forming: Add the raw materials mixed in step (1) into the mold cavity, carry out pressing and forming and then demold;

[0050] (3) Sintering: Sinter and form the blank obtained by demolding in step (2) in a sintering furnace under nitrogen protection.

[0051] Further, in step 1), the mixing and stirring speed is 130 - 150 rpm, and the stirring time is 1 - 2 h.

[0052] Further, in step 2), the cold pressing forming pressure is 750 - 850 Mpa, and the cold pressing forming holding time is 20 - 40 min.

[0053] Further, in step 3), it includes:

[0054] Preheating stage: Preheat the blank after cold pressing forming. The preheating temperature is 110 - 130 °C, and the preheating time is 20 min;

[0055] Heating-up stage: The heating-up rate is 35 - 50 °C / min. After heating up to 850 °C, keep it warm for 45 min;

[0056] Sintering stage: The heating-up rate is 100 °C / min. After heating up to 1250 - 1320 °C, keep it warm for 2 - 3 h.

[0057] Further, in step 3), the nitrogen pressure is 0.3 - 0.5 Mpa.

[0058] According to the third aspect of the present invention, a bearing is provided, which is prepared by using the preparation method of the above powder metallurgy material.

[0059] According to the inventive concept provided above, the present application provides the following embodiments to illustrate the technical effects of the present application.

[0060] Example 1

[0061] This example provides a preparation method of a powder metallurgy material for producing a powder metallurgy material, including the following steps:

[0062] Preparation of pore-forming additive: The raw materials include the following parts by weight: 35 parts of copper sulfate, 23 parts of titanium dioxide, 18 parts of silicon nitride, and 3 parts of potassium borohydride;

[0063] The processing steps include:

[0064] First, weigh the corresponding amounts of copper sulfate, titanium dioxide, silicon nitride, and potassium borohydride;

[0065] Secondly, put copper sulfate, titanium dioxide, and silicon nitride into deionized water, adjust the pH to 7 - 8 with sodium hydroxide, add potassium borohydride while stirring, control the temperature at 65 - 80 °C after adding, continue stirring for 2 h, centrifuge to collect the precipitate and wash it repeatedly;

[0066] Thirdly, transfer the above precipitate to a tube furnace, set the temperature at 150 °C and dry for 3 h, then gradually heat up to 1250 °C and heat under argon protection for 6 h;

[0067] Finally, after cooling, break up the above pore-forming additive, grind it into powder, and pass it through a 300-mesh sieve.

[0068] Preparation of other raw materials: The raw materials include the following parts by weight:

[0069] 0.8 parts of carbon nanotubes, 2.5 parts of copper, 1.8 parts of aluminum, 2.0 parts of nickel, 0.8 parts of titanium. Taking 100 parts as a reference, the balance is iron. Pass each raw material component: carbon nanotubes, copper, aluminum, nickel, titanium and iron through a 300-mesh sieve.

[0070] The specific processing steps of the powder metallurgy material are as follows:

[0071] (1) Mixing: Put each raw material component of the powder metallurgy material into a mixer to make the raw materials evenly mixed; the mixing and stirring speed is 135 rpm, and the stirring time is 1.5 h.

[0072] (2) Cold pressing and forming: Add the mixed raw materials in step (1) into the mold cavity, press and form them and then demold; the cold pressing and forming pressure is 795 Mpa, and the cold pressing and forming holding time is 30 min.

[0073] (3) Sintering: Under the protection of nitrogen, sinter and form the blank obtained by demolding in step (2) in the nitrogen atmosphere of the sintering furnace. The nitrogen pressure is 0.3 Mpa, including:

[0074] Preheating stage: Preheat the blank after cold pressing and forming. The preheating temperature is 115 °C, and the preheating time is 20 min;

[0075] Heating-up stage: The heating-up rate is 40 °C / min. After heating up to 850 °C, hold for 45 min;

[0076] Sintering stage: The heating-up rate is 100 °C / min. After heating up to 1263 °C, hold for 3 h.

[0077] Detect the hardness and density of the finished product. The specific detection results are shown in Table 1.

[0078] Example 2

[0079] This example provides a preparation method of a powder metallurgy material for producing a powder metallurgy material, including the following steps:

[0080] Preparation of pore-forming additives: The raw materials include the following parts by weight: 40 parts of copper sulfate, 20 parts of titanium dioxide, 23 parts of silicon nitride and 4 parts of potassium borohydride;

[0081] The processing steps include:

[0082] First, weigh the corresponding amounts of copper sulfate, titanium dioxide, silicon nitride and potassium borohydride;

[0083] Secondly, put copper sulfate, titanium dioxide and silicon nitride into deionized water, adjust the pH to 7 - 8 with sodium hydroxide, add potassium borohydride while stirring, control the temperature at 65 - 80 °C after adding, continue stirring for 2.5 h, centrifuge to collect the precipitate and wash it repeatedly;

[0084] Thirdly, transfer the above precipitate to a tube furnace, set the temperature at 145 °C and dry for 4 h, then gradually raise the temperature to 1180 °C and heat under argon protection for 10 h;

[0085] Finally, after cooling, break up the above pore-forming additive, grind it into powder and sieve it through a 300 - mesh sieve.

[0086] Preparation of other raw materials: including the following raw materials by weight:

[0087] 1.0 parts of carbon nanotubes, 2.1 parts of copper, 2.2 parts of aluminum, 3.3 parts of nickel, 0.6 parts of titanium, based on 100 parts, the balance is iron. Sieve each raw material component: carbon nanotubes, copper, aluminum, nickel, titanium and iron through a 300 - mesh sieve.

[0088] The specific processing steps of the powder metallurgy material are as follows:

[0089] (1) Mixing: Put each raw material component of the powder metallurgy material into a mixer to mix the raw materials evenly; the mixing and stirring speed is 145 rpm and the stirring time is 1 h.

[0090] (2) Cold pressing and forming: Add the mixed raw materials in step (1) into the mold cavity, press and form and then demold; the cold pressing and forming pressure is 832 Mpa and the cold pressing and forming holding time is 25 min.

[0091] (3) Sintering: Sinter and form the blank obtained by demolding in step (2) under nitrogen protection in a nitrogen atmosphere in a sintering furnace, the nitrogen pressure is 0.4 Mpa, including:

[0092] Preheating stage: Preheat the blank after cold pressing and forming, the preheating temperature is 120 °C and the preheating time is 20 min;

[0093] Heating-up stage: The heating-up rate is 45 °C / min, heat up to 850 °C and then hold for 45 min;

[0094] Sintering stage: The heating-up rate is 100 °C / min, heat up to 1282 °C and then hold for 2.5 h.

[0095] Detect the hardness and density of the finished product, and the specific detection results are shown in Table 1.

[0096] Example 3

[0097] This example provides a preparation method of a powder metallurgy material for producing a powder metallurgy material, including the following steps:

[0098] Preparation of pore-forming additive: The raw materials include the following parts by weight: 45 parts of copper sulfate, 25 parts of titanium dioxide, 21 parts of silicon nitride, and 4.5 parts of potassium borohydride;

[0099] The processing steps include:

[0100] First, weigh the corresponding amounts of copper sulfate, titanium dioxide, silicon nitride, and potassium borohydride;

[0101] Second, put copper sulfate, titanium dioxide, and silicon nitride into deionized water, adjust the pH to 7 - 8 with sodium hydroxide, add potassium borohydride while stirring, control the temperature at 65 - 80 °C after adding, continue stirring for 3.5 h, centrifuge to collect the precipitate and wash it multiple times;

[0102] Third, transfer the above precipitate to a tubular furnace, set the temperature at 135 °C and dry for 4.8 h, then gradually heat up to 1300 °C and heat under argon protection for 5 h;

[0103] Finally, after cooling, break up the above pore-forming additive, grind it into powder, and sieve it through a 300 - mesh sieve.

[0104] Preparation of other raw materials: The raw materials include the following parts by weight:

[0105] 0.6 part of carbon nanotubes, 1.7 parts of copper, 2.7 parts of aluminum, 3.0 parts of nickel, 0.5 part of titanium. Taking 100 parts as a reference, the balance is iron. Pass each raw material component: carbon nanotubes, copper, aluminum, nickel, titanium, and iron through a 300 - mesh sieve.

[0106] The specific processing steps of the powder metallurgy material are as follows:

[0107] (1) Mixing: Put each raw material component of the powder metallurgy material into a mixer to make the raw materials evenly mixed; the mixing and stirring speed is 130 rpm, and the stirring time is 2 h.

[0108] (2) Cold pressing and forming: Add the raw materials mixed in step (1) into the mold cavity, press and form, and then demold; the cold pressing and forming pressure is 846 Mpa, and the cold pressing and forming holding time is 22 min.

[0109] (3) Sintering: Sinter and form the blank obtained by demolding in step (2) under nitrogen protection in a sintering furnace with a nitrogen atmosphere, the nitrogen pressure is 0.4 Mpa, including:

[0110] Preheating stage: Preheat the blank after cold pressing and forming, the preheating temperature is 125 °C, and the preheating time is 20 min;

[0111] Heating-up stage: The heating-up rate is 37 °C / min, heat up to 850 °C and then hold for 45 min;

[0112] Sintering stage: The heating rate is 100 °C / min. After heating to 1295 °C, keep it warm for 2.3 h.

[0113] Perform hardness and density tests on the finished product. For specific test results, please refer to Table 1.

[0114] Example 4

[0115] This example provides a preparation method of a powder metallurgy material for producing a powder metallurgy material, including the following steps:

[0116] Preparation of pore-forming additives: The raw materials include the following parts by weight: 50 parts of copper sulfate, 27 parts of titanium dioxide, 15 parts of silicon nitride, and 5 parts of potassium borohydride;

[0117] The processing steps include:

[0118] First, weigh the corresponding amounts of copper sulfate, titanium dioxide, silicon nitride, and potassium borohydride;

[0119] Secondly, put copper sulfate, titanium dioxide, and silicon nitride into deionized water, adjust the pH to 7-8 with sodium hydroxide, add potassium borohydride while stirring, control the temperature at 65-80 °C after the addition, continue stirring for 4 h, centrifuge to collect the precipitate and wash it repeatedly;

[0120] Thirdly, transfer the above precipitate to a tubular furnace, set the temperature at 155 °C and dry for 3.5 h, and then gradually heat up to 1200 °C and heat under argon protection for 8 h;

[0121] Finally, after cooling, break up the above pore-forming additives, grind them into powder, and pass through a 300-mesh sieve.

[0122] Preparation of other raw materials: The raw materials include the following parts by weight:

[0123] 1.1 parts of carbon nanotubes, 1.5 parts of copper, 3.1 parts of aluminum, 2.4 parts of nickel, 0.6 parts of titanium. Based on 100 parts, the balance is iron. Pass each raw material component: carbon nanotubes, copper, aluminum, nickel, titanium, and iron through a 300-mesh sieve.

[0124] The specific processing steps of the powder metallurgy material are as follows:

[0125] (1) Mixing: Put each raw material component of the powder metallurgy material into a mixer to mix the raw materials evenly; the mixing and stirring speed is 141 rpm, and the stirring time is 1.3 h.

[0126] (2) Cold pressing and forming: Add the raw materials mixed in step (1) into the mold cavity, perform pressing and forming, and then demold; the cold pressing and forming pressure is 790 Mpa, and the cold pressing and forming holding time is 36 min.

[0127] (3) Sintering: The blank obtained by demolding in step (2) is sintered and formed in a nitrogen atmosphere in a sintering furnace under nitrogen protection, with a nitrogen pressure of 0.5 Mpa, including:

[0128] Preheating stage: The blank after cold pressing is preheated, with a preheating temperature of 126 °C and a preheating time of 20 min;

[0129] Heating-up stage: The heating-up rate is 46 °C / min, and after heating up to 850 °C, it is held for 45 min;

[0130] Sintering stage: The heating-up rate is 100 °C / min, and after heating up to 1313 °C, it is held for 2 h.

[0131] The finished product is subjected to hardness and density tests, and the specific test results are shown in Table 1.

[0132] Comparative Example 1

[0133] This Comparative Example 1 follows the preparation method of Example 1, but without adding a pore-forming additive. Specifically as follows:

[0134] This comparative example provides a preparation method of a powder metallurgy material for producing a powder metallurgy material, including the following steps:

[0135] Preparation of raw materials: The raw materials include the following parts by weight:

[0136] 0.8 parts of carbon nanotubes, 2.5 parts of copper, 1.8 parts of aluminum, 2.0 parts of nickel, 0.8 parts of titanium. Taking 100 parts as a reference, the balance is iron. All raw material components: carbon nanotubes, copper, aluminum, nickel, titanium and iron are passed through a 300-mesh sieve.

[0137] The specific processing steps of the powder metallurgy material are as follows:

[0138] (1) Mixing: Put the raw material components of the powder metallurgy material into a mixer to mix the raw materials evenly; the mixing and stirring speed is 135 rpm, and the stirring time is 1.5 h.

[0139] (2) Cold pressing: Add the mixed raw materials in step (1) into the mold cavity, and perform cold pressing and then demolding; the cold pressing pressure is 795 Mpa, and the cold pressing holding time is 30 min.

[0140] (3) Sintering: The blank obtained by demolding in step (2) is sintered and formed in a nitrogen atmosphere in a sintering furnace under nitrogen protection, with a nitrogen pressure of 0.3 Mpa, including:

[0141] Preheating stage: The blank after cold pressing is preheated, with a preheating temperature of 115 °C and a preheating time of 20 min;

[0142] Heating stage: The heating rate is 40 °C / min. After heating to 850 °C, keep it warm for 45 min;

[0143] Sintering stage: The heating rate is 100 °C / min. After heating to 1263 °C, keep it warm for 3 h.

[0144] Conduct hardness and density tests on the finished product. For the specific test results, please refer to Table 1.

[0145] Table 1: Hardness and density test results of Examples 1-4 and Comparative Example 1

[0146]

[0147] As can be seen from Table 1 above, in Examples 1-4 with pore-forming additives added, as the addition amount increases, the density of the finished product continuously decreases, indicating an increase in porosity. In Comparative Example 1 without addition, the density is significantly higher than that of Examples 1-4. At the same time, in the case of adding pore-forming additives, the hardness of Examples 1-4 continuously decreases, but in terms of the overall decreasing trend, the decrease amplitude is not large. Of course, in Comparative Example 1 without pore-forming additives, its hardness is the highest, but compared with Example 1 with pore-forming additives added, under the same proportion, its hardness decreases less and its density decreases more, achieving the expected experimental effect.

[0148] In the technical solution of this application, a pore-forming additive is creatively added to the iron-based powder metallurgy material. It reacts by reacting copper sulfate, titanium dioxide and silicon nitride in the state of a reducing agent to generate a porous material, which can improve the porosity of the finished product in the processing of powder metallurgy materials; at the same time, combined with the blank sintering method of this application, its hardness can also meet the ideal requirements.

[0149] Although the present invention has been described in detail above with general descriptions and specific examples, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A powder metallurgy material, characterized in that, Comprising the following raw materials in parts by weight: 0.5 - 1.1 parts of carbon nanotubes, 1.5 - 2.5 parts of copper, 1.8 - 3.2 parts of aluminum, 2.0 - 3.5 parts of nickel, 0.5 - 0.8 parts of titanium, 0.1 - 0.4 parts of pore-forming additive, based on 100 parts, the balance being iron; The pore-forming additive comprises the following processing steps: Wherein the raw materials Comprise the following parts by weight: 30 - 50 parts of copper sulfate, 20 - 30 parts of titanium dioxide, 10 - 25 parts of silicon nitride, and 3 - 5 parts of potassium borohydride; The processing steps include: First, weigh the corresponding amounts of copper sulfate, titanium dioxide, silicon nitride, and potassium borohydride; Secondly, put copper sulfate, titanium dioxide, and silicon nitride into deionized water, adjust the pH to 7 - 8 with sodium hydroxide, add potassium borohydride while stirring, control the temperature at 65 - 80 °C after adding, continue stirring for 1.5 - 4.0 h, centrifuge to collect the precipitate and wash it several times; Thirdly, transfer the above precipitate to a tube furnace, set the temperature at 130 - 160 °C and dry for 3 - 5 h, then gradually increase the temperature to 1100 - 1300 °C and heat for 3 - 12 h under argon protection to obtain the pore-forming additive; Finally, after cooling, break up the above pore-forming additive, grind it into powder, and pass through a 300-mesh sieve.

2. The powder metallurgy material according to claim 1, characterized in that, Comprising the following raw materials in parts by weight: 0.8 - 1.0 parts of carbon nanotubes, 1.7 - 2.1 parts of copper, 2.2 - 3.1 parts of aluminum, 2.4 - 3.3 parts of nickel, 0.6 - 0.8 parts of titanium, 0.2 - 0.4 parts of pore-forming additive, based on 100 parts, the balance being iron.

3. The powder metallurgy material according to claim 1, characterized in that, The carbon nanotubes, copper, aluminum, nickel, titanium, and iron all pass through a 300-mesh sieve.

4. A method for preparing a powder metallurgy material, characterized in that, For producing the powder metallurgy material as described in claim 1, comprising the following steps: (1) Mixing: Put each raw material component of the powder metallurgy material into a mixer to make the raw materials evenly mixed; (2) Cold pressing and forming: Add the raw materials mixed in step (1) into the mold cavity, press and form, and then demold; (3) Sintering: Sinter the blank obtained by demolding in step (2) in a sintering furnace under nitrogen protection.

5. The preparation method of the powder metallurgy material according to claim 4, characterized in that, Wherein, In step 1), the mixing stirring speed is 130 - 150 rpm, and the stirring time is 1 - 2 h.

6. The preparation method of the powder metallurgy material according to claim 4, characterized in that, Wherein, In step 2), the cold pressing and forming pressure is 750 - 850 Mpa, and the cold pressing and forming holding time is 20 - 40 min.

7. The preparation method of the powder metallurgy material according to claim 4, characterized in that, Wherein, In step 3), it includes: Preheating stage: Preheat the blank after cold pressing and forming, the preheating temperature is 110 - 130 °C, and the preheating time is 20 min; Heating-up stage: The heating-up rate is 35 - 50 °C / min, heat up to 850 °C and then hold for 45 min; Sintering stage: The heating-up rate is 100 °C / min, heat up to 1250 - 1320 °C and then hold for 2 - 3 h.

8. The preparation method of the powder metallurgy material according to claim 4, characterized in that, Wherein, In step 3), the nitrogen pressure is 0.3 - 0.5 Mpa.

9. A bearing, characterized in that, Prepared by using the preparation method of the powder metallurgy material according to any one of claims 4 - 8.

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