A cemented carbide bearing for hard rock deep drilling and a method for manufacturing the same

Abstract

The application relates to the technical field of hard alloy materials, and discloses a hard alloy bearing for hard rock deep drilling and a preparation method thereof, which comprises the following preparation steps: mixing tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing fillers, obtaining mixed materials after ball milling; placing the mixed materials in a bearing mold to press into a preform; placing the preform in a sintering furnace to sinter, cooling to room temperature, and obtaining the hard alloy bearing through post-processing, grinding and polishing. The reinforcing fillers can be adsorbed to the surface of the alloy powder, so that the alloy powder is adhered to form a dense structure; the reinforcing fillers can improve the heat resistance of the reinforced hard alloy bearing, can also absorb and weaken the stress generated by external force, and can enhance the compressive strength of the alloy bearing; in addition, the reinforcing fillers can supplement the carbon content in the alloy, avoid additional carbon loss caused by the high oxygen content in the alloy bearing during the preparation process, and affect the mechanical properties of the alloy bearing.

Description

Technical Field

[0001] The present invention relates to the technical field of cemented carbide materials, in particular to a cemented carbide bearing for hard rock deep drilling and a preparation method thereof. Background Art

[0002] Cemented carbide is a type of cemented carbide bearing produced by powder metallurgy, which uses refractory metal carbide (tungsten carbide) as the hard phase and transition metal elements (cobalt, nickel, iron, etc.) as the bonding phase. It has excellent wear resistance, compressive strength, hardness, labor strength and load-bearing capacity, as well as good plasticity and impact toughness. As a bearing material, it is widely used in the field of deep hard rock drilling.

[0003] During the powder metallurgy process, cemented carbide bearings have the problem of poor structural uniformity. Their hardness, toughness and strength are low, making it difficult for them to withstand the impact strength brought by deep hard rock drilling. As the depth of deep hard rock drilling increases, the formation temperature becomes higher, and the heat is difficult to diffuse in the cemented carbide bearings, causing the cemented carbide bearings to deteriorate and affecting their service life. Summary of the Invention

[0004] The present invention provides a cemented carbide bearing for hard rock deep drilling and a preparation method thereof, which solves the problems of poor structural uniformity of cemented carbide bearings and difficulty in heat diffusion in the cemented carbide bearings, which leads to deterioration of the cemented carbide bearings.

[0005] The technical solution of the present invention:

[0006] A method for preparing a cemented carbide bearing for hard rock deep drilling comprises the following steps:

[0007] S1. The tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler are mixed and ball-milled to obtain a mixture;

[0008] S2. The mixture is placed in a bearing mold and pressed into a preform;

[0009] S3. The preform is placed in a sintering furnace, sintered, cooled to room temperature, and post-processed, ground, and polished to obtain a cemented carbide bearing;

[0010] The reinforcing filler is obtained by surface treating the composite material with carboxymethyl cellulose and then mixing and reacting it with sulfonated lignin.

[0011] The composite material is made by adhering nano-silicon nitride to the surface of silicon carbide nanosheets through tannic acid, then mixing it with glucose, carbonizing it at high temperature, and then intercalating it into the interlayers of graphene oxide.

[0012] Furthermore, in step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:(5-6):(2-4):(4-6):(6-8):(1-3):(5-6).

[0013] Furthermore, in step S1, the ball mill is used, the ball-to-material ratio is (8-10):1, the rotation speed is 200-300 r / min, and the ball milling time is 15-20 h.

[0014] Furthermore, in step S2, the pressing pressure is 300-350 MPa, and the pressing time is 30-40 s.

[0015] Furthermore, in step S3, the sintering temperature is 1300-1380°C, the sintering time is 2-4h, the sintering pressure is 40-50Pa, and the sintering is carried out in a nitrogen atmosphere with a nitrogen introduction rate of 50-60mL / min.

[0016] Furthermore, the reinforcing filler is specifically prepared by the following steps:

[0017] A1. Add tannic acid to ethanol and stir until completely dissolved. Add silicon carbide nanosheets and stir. Add nano-silicon nitride and continue stirring. Filter, wash, and dry to obtain nano-silicon nitride-loaded silicon carbide nanosheets.

[0018] A2. The silicon carbide nanosheets loaded with nano-silicon nitride, glucose, and citric acid were added to ethanol, hydrochloric acid was added, stirred, filtered, washed, dried, potassium hydroxide solution was added, nitrogen was introduced, carbonized, cooled to room temperature, removed, washed, and dried to obtain modified silicon carbide nanosheets;

[0019] A3. Graphene oxide was added to deionized water, stirred evenly, modified silicon carbide nanosheets were added, and after ultrasonic treatment, the mixture was filtered, washed, and dried to obtain a composite material;

[0020] A4. Add carboxymethyl cellulose to deionized water and stir evenly. Add the composite material and stir. Add sulfonated lignin and hydrochloric acid. After stirring for reaction, filter, wash, and dry to obtain a reinforcing filler.

[0021] Furthermore, during the above-mentioned reaction A1, tannic acid contains a large number of phenolic hydroxyl groups and has good adhesion properties, so that nano-silicon nitride adheres to the surface of silicon carbide nanosheets through tannic acid, thereby obtaining silicon carbide nanosheets loaded with nano-silicon nitride.

[0022] Furthermore, in the above-mentioned A2 reaction process, citric acid is used as a linker, so that glucose is coated on the surface of the silicon carbide nanosheet loaded with nano-silicon nitride through citric acid. After high-temperature carbonization, the glucose is thermally decomposed to form a dense carbon layer. Potassium hydroxide solution is used as an activator to form pores on the surface of the dense carbon layer, thereby realizing the synthesis of a porous carbon structure on the surface of the silicon carbide nanosheet loaded with nano-silicon nitride, and obtaining a modified silicon carbide nanosheet.

[0023] Furthermore, during the above-mentioned reaction A3, the interlayer gaps of graphene oxide are abundant, and ultrasonic treatment can weaken the bonding force between the graphene oxide layers, so that the modified silicon carbide nanosheets are intercalated between the graphene oxide layers to form a composite material.

[0024] Furthermore, in the above-mentioned A4 reaction process, carboxymethyl cellulose serves as a binder, and the carboxyl groups it contains can bond with the oxygen-containing functional groups on the surface of the composite material through hydrogen bonds, so that the carboxymethyl cellulose is coated on the surface of the composite material; the carboxyl groups contained in the carboxymethyl cellulose can combine with the hydroxyl groups of the sulfonated lignin, so that the sulfonated lignin is cross-linked to form a network structure coated on the surface of the composite material, serving as a reinforcing filler.

[0025] Furthermore, in step A1, the ratio of tannic acid, ethanol, silicon carbide nanosheets and nano-silicon nitride is (0.2-0.4) g: (35-45) mL: (1-1.4) g: (0.6-1) g.

[0026] Furthermore, in step A2, the amount ratio of the nano-silicon nitride-loaded silicon carbide nanosheets, glucose, citric acid, ethanol, hydrochloric acid and potassium hydroxide solution is (1-2) g: (2-3) g: (0.4-0.6) g: (90-110) mL: (1-2) mL: (4-6) mL.

[0027] Furthermore, in step A3, the ratio of graphene oxide, deionized water, and modified silicon carbide nanosheets is (1-2) g: (80-120) mL: (1-1.4) g.

[0028] Furthermore, in step A4, the ratio of carboxymethyl cellulose, deionized water, composite material, sulfonated lignin and hydrochloric acid is (0.6-1) g: (75-85) mL: (1.4-1.8) g: (1.5-2.5) g: (1-3) mL.

[0029] The present invention has the following beneficial effects:

[0030] (1) In the technical solution of the present invention, nano-silicon nitride is adhered to the surface of silicon carbide nanosheets through tannic acid. On the one hand, nano-silicon nitride has a high thermal conductivity and can improve the heat dissipation rate of cemented carbide bearings, thereby avoiding the problem that as the depth of deep drilling in hard rock increases, the formation temperature becomes high and the heat is difficult to diffuse in the cemented carbide bearings, resulting in deterioration of the cemented carbide bearings and affecting the service life of the cemented carbide bearings. On the other hand, silicon carbide nanosheets, as a carrier of nano-silicon nitride, can improve the dispersibility of nano-silicon nitride in the alloy and improve the structural uniformity of the alloy.

[0031] (2) In the technical solution of the present invention, a porous carbon structure is synthesized on the surface of silicon carbide nanosheets loaded with nano-silicon nitride. On the one hand, the synthesized porous carbon has high adsorption performance and can adsorb and fix nano-silicon nitride, thereby preventing the nano-silicon nitride from falling off when the cemented carbide bearing is used under high wear resistance and high pressure, causing cracks in the alloy bearing. The high specific surface area and pore structure of the porous carbon can enhance the heat conduction path of the cemented carbide bearing and improve the heat dissipation performance. On the other hand, the nano-silicon nitride adsorbed into the pores of the porous carbon serves as the supporting skeleton of the porous carbon, avoiding the collapse of the cavities of the porous carbon. In addition, during the sintering process, the carbon element contained in the porous carbon can form a metal carbide reinforcement phase with the molten metal powder, filling the gaps in the alloy bearing, thereby improving the density of the alloy bearing and enhancing the mechanical strength of the alloy bearing.

[0032] (3) In the technical solution of the present invention, modified silicon carbide nanosheets are intercalated between graphene oxide layers. On the one hand, the nano silicon nitride and porous carbon between the layers of the formed layered composite material serve as heat conduction channels, further enhancing the heat conduction path of the cemented carbide bearing and improving the heat dissipation performance. In addition, the formed layered composite material can absorb and reduce the stress generated by external forces, thereby enhancing the compressive strength of the alloy bearing. On the other hand, the alloy powder melt can be adsorbed between the layers of the layered composite material, so that the composite filler is evenly dispersed in the alloy, thereby improving the density of the alloy bearing.

[0033] (4) In the technical solution of the present invention, carboxymethyl cellulose is coated on the surface of the layered composite material and then reacts with sulfonated lignin to form a cross-linked network structure coated on the surface of the layered composite material. On the one hand, sulfonated lignin and carboxymethyl cellulose contain a large number of hydroxyl groups, which can be adsorbed on the surface of the alloy powder to improve the density of the alloy powder. On the other hand, during the sintering process, the lignin-based cross-linked network structure is carbonized to form a dense cross-linked carbon network structure, which can supplement the carbon content in the alloy and avoid additional carbon loss during the preparation of the alloy bearing due to the high oxygen content, thereby affecting the mechanical properties of the alloy bearing. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0035] The raw materials used in the embodiments of the present application are shown as follows, and all the reagents used are analytical grade.

[0036] The average particle size of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder and graphite powder is 2.5 um.

[0037] The silicon carbide nanosheet has a sheet diameter of 10 um and is a brand of Deke Island Gold, Beijing Deke Island Gold Technology Co., Ltd.

[0038] The nano-silicon nitride has a particle size of 20 nm and is purchased from Hubei Langbo Wan Biological Medicine Co., Ltd.

[0039] The graphene oxide has a sheet diameter of 10 um and is purchased from Hangzhou Zemeng New Material Co., Ltd.

[0040] Embodiment 1

[0041] A preparation method of a cemented carbide bearing for hard rock deep drilling, comprising the following preparation steps:

[0042] S1. mixing tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing fillers, and obtaining a mixture after ball milling;

[0043] S2. placing the mixture in a bearing mold for pressing into a preform;

[0044] S3. placing the preform in a sintering furnace for sintering, cooling to room temperature, and obtaining the cemented carbide bearing after post-processing, grinding and polishing.

[0045] In step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing fillers is 100:5:2:4:6:1:5;

[0046] In step S1, a ball mill is used for ball milling, the ball-to-material ratio is 8:1, the rotation speed is 200 r / min, and the ball milling time is 15 h;

[0047] In step S2, the pressing pressure is 300 MPa, and the pressing time is 30 s;

[0048] In step S3, the sintering temperature is 1300℃, the sintering time is 2 h, the sintering pressure is 40 Pa, the sintering is carried out in a nitrogen atmosphere, and the nitrogen inlet rate is 50 mL / min.

[0049] The reinforcing filler is specifically prepared by the following steps:

[0050] A1. Add 0.2 g of tannic acid to 35 mL of ethanol and stir until completely dissolved. Then add 1 g of silicon carbide nanosheets and stir at 70°C for 40 minutes. Then add 0.6 g of nano-silicon nitride and continue stirring for 40 minutes. The mixture is filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain silicon carbide nanosheets loaded with nano-silicon nitride.

[0051] A2. 1 g of silicon nitride nanosheets loaded with silicon carbide nanosheets, 2 g of glucose, and 0.4 g of citric acid were added to 90 mL of ethanol. 1 mL of 36% hydrochloric acid was added and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 4 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain modified silicon carbide nanosheets.

[0052] A3. 1 g of graphene oxide was added to 80 mL of deionized water and stirred. 1 g of modified silicon carbide nanosheets was added and ultrasonicated at 40 kHz for 20 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 80°C for 10 min to obtain a composite material.

[0053] A4. Add 0.6 g of carboxymethyl cellulose to 75 mL of deionized water and stir well. Then add 1.4 g of the composite material and stir for 30 minutes. Then add 1.5 g of sulfonated lignin and 1 mL of 36% hydrochloric acid. Stir and react at 60°C for 20 minutes. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 minutes to obtain the reinforcing filler.

[0054] Example 2

[0055] A method for preparing a cemented carbide bearing for hard rock deep drilling comprises the following steps:

[0056] S1. The tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler are mixed and ball-milled to obtain a mixture;

[0057] S2. The mixture is placed in a bearing mold and pressed into a preform;

[0058] S3. Place the prefabricated body in a sintering furnace for sintering, cool to room temperature, and then post-process, grind, and polish to obtain a cemented carbide bearing.

[0059] Wherein, in step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:5.5:3:5:7:2:5.5;

[0060] In step S1, the ball mill is used, the ball-to-material ratio is 9:1, the rotation speed is 250 r / min, and the ball milling time is 18 h;

[0061] In step S2, the pressing pressure is 330 MPa and the pressing time is 35 s;

[0062] In step S3, the sintering temperature is 1340° C., the sintering time is 3 h, the sintering pressure is 45 Pa, and the sintering is carried out in a nitrogen atmosphere with a nitrogen introduction rate of 55 mL / min.

[0063] The reinforcing filler is specifically prepared by the following steps:

[0064] A1. Add 0.3 g of tannic acid to 40 mL of ethanol and stir until completely dissolved. Then add 1.2 g of silicon carbide nanosheets and stir at 70°C for 40 minutes. Then add 0.8 g of nano-silicon nitride and continue stirring for 40 minutes. The mixture is filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain silicon carbide nanosheets loaded with nano-silicon nitride.

[0065] A2. 1.5 g of nano-silicon nitride-loaded silicon carbide nanosheets, 2.5 g of glucose, and 0.5 g of citric acid were added to 100 mL of ethanol. 1.5 mL of 36% hydrochloric acid was added and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain modified silicon carbide nanosheets.

[0066] A3. 1.5 g of graphene oxide was added to 100 mL of deionized water and stirred. 1.2 g of modified silicon carbide nanosheets was added and ultrasonicated at 40 kHz for 20 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 80 ° C for 10 min to obtain a composite material.

[0067] A4. Add 0.8 g of carboxymethyl cellulose to 80 mL of deionized water and stir well. Then add 1.6 g of the composite material and stir for 30 minutes. Then add 2 g of sulfonated lignin and 2 mL of 36% hydrochloric acid. Stir and react at 60°C for 20 minutes. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 minutes to obtain the reinforcing filler.

[0068] Example 3

[0069] A method for preparing a cemented carbide bearing for hard rock deep drilling comprises the following steps:

[0070] S1. The tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler are mixed and ball-milled to obtain a mixture;

[0071] S2. The mixture is placed in a bearing mold and pressed into a preform;

[0072] S3. Place the prefabricated body in a sintering furnace for sintering, cool to room temperature, and then post-process, grind, and polish to obtain a cemented carbide bearing.

[0073] Wherein, in step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:6:4:6:8:3:6;

[0074] In step S1, the ball mill is used, the ball-to-material ratio is 10:1, the rotation speed is 300 r / min, and the ball milling time is 20 h;

[0075] In step S2, the pressing pressure is 350 MPa and the pressing time is 40 s;

[0076] In step S3, the sintering temperature is 380° C., the sintering time is 4 h, the sintering pressure is 50 Pa, and the sintering is carried out in a nitrogen atmosphere with a nitrogen introduction rate of 60 mL / min.

[0077] The reinforcing filler is specifically prepared by the following steps:

[0078] A1. Add 0.4 g of tannic acid to 45 mL of ethanol and stir until completely dissolved. Then add 1.4 g of silicon carbide nanosheets and stir at 70°C for 40 minutes. Then add 1 g of nano-silicon nitride and continue stirring for 40 minutes. The mixture is filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain silicon carbide nanosheets loaded with nano-silicon nitride.

[0079] A2. 2 g of silicon nitride nanosheets loaded with silicon carbide nanosheets, 3 g of glucose, and 0.6 g of citric acid were added to 110 mL of ethanol. 2 mL of 36% hydrochloric acid was added and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 6 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain modified silicon carbide nanosheets.

[0080] A3. 2 g of graphene oxide was added to 120 mL of deionized water and stirred. 1.4 g of modified silicon carbide nanosheets was added and ultrasonicated at 40 kHz for 20 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 80 ° C for 10 min to obtain a composite material.

[0081] A4. Add 1 g of carboxymethyl cellulose to 85 mL of deionized water and stir until well combined. Then, add 1.8 g of the composite material and stir for 30 minutes. Then, add 2.5 g of sulfonated lignin and 3 mL of 36% hydrochloric acid. Stir and react at 60°C for 20 minutes. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 minutes to obtain the reinforcing filler.

[0082] Comparative Example 1

[0083] A method for preparing a cemented carbide bearing for hard rock deep drilling comprises the following steps:

[0084] S1. The tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler are mixed and ball-milled to obtain a mixture;

[0085] S2. The mixture is placed in a bearing mold and pressed into a preform;

[0086] S3. Place the prefabricated body in a sintering furnace for sintering, cool to room temperature, and then post-process, grind, and polish to obtain a cemented carbide bearing.

[0087] Wherein, in step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:6:4:6:8:3:6;

[0088] In step S1, the ball mill is used, the ball-to-material ratio is 10:1, the rotation speed is 300 r / min, and the ball milling time is 20 h;

[0089] In step S2, the pressing pressure is 350 MPa and the pressing time is 40 s;

[0090] In step S3, the sintering temperature is 380° C., the sintering time is 4 h, the sintering pressure is 50 Pa, and the sintering is carried out in a nitrogen atmosphere with a nitrogen introduction rate of 60 mL / min.

[0091] The reinforcing filler is specifically prepared by the following steps:

[0092] A1. 45 mL of ethanol and 1.4 g of silicon carbide nanosheets were stirred at 70°C for 40 min. 1 g of nano-silicon nitride was added and stirred for another 40 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain nano-silicon nitride-loaded silicon carbide nanosheets.

[0093] A2. 2 g of silicon nitride nanosheets loaded with silicon carbide nanosheets, 3 g of glucose, and 0.6 g of citric acid were added to 110 mL of ethanol. 2 mL of 36% hydrochloric acid was added and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 6 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain modified silicon carbide nanosheets.

[0094] A3. 2 g of graphene oxide was added to 120 mL of deionized water and stirred. 1.4 g of modified silicon carbide nanosheets was added and ultrasonicated at 40 kHz for 20 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 80 ° C for 10 min to obtain a composite material.

[0095] A4. Add 1 g of carboxymethyl cellulose to 85 mL of deionized water and stir until well combined. Then, add 1.8 g of the composite material and stir for 30 minutes. Then, add 2.5 g of sulfonated lignin and 3 mL of 36% hydrochloric acid. Stir and react at 60°C for 20 minutes. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 minutes to obtain the reinforcing filler.

[0096] Comparative Example 2

[0097] A method for preparing a cemented carbide bearing for hard rock deep drilling comprises the following steps:

[0098] S1. The tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler are mixed and ball-milled to obtain a mixture;

[0099] S2. The mixture is placed in a bearing mold and pressed into a preform;

[0100] S3. Place the prefabricated body in a sintering furnace for sintering, cool to room temperature, and then post-process, grind, and polish to obtain a cemented carbide bearing.

[0101] Wherein, in step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:6:4:6:8:3:6;

[0102] In step S1, the ball mill is used, the ball-to-material ratio is 10:1, the rotation speed is 300 r / min, and the ball milling time is 20 h;

[0103] In step S2, the pressing pressure is 350 MPa and the pressing time is 40 s;

[0104] In step S3, the sintering temperature is 380 DEG C, the sintering time is 4h, the sintering pressure is 50Pa, the sintering is carried out under nitrogen atmosphere, and the nitrogen flow rate is 60mL / min.

[0105] The reinforcing filler is prepared by the following steps:

[0106] A1. 0.4g tannic acid was added into 45mL ethanol, stirred until completely dissolved, 1.4g silicon carbide nanosheet was added, stirred at 70 DEG C for 40min, filtered, washed with deionized water for 3 times, dried in an oven at 70 DEG C for 10min, to obtain silicon carbide nanosheet composite;

[0107] A2. 2g silicon carbide nanosheet composite, 3g glucose and 0.6g citric acid were added into 110mL ethanol, 2mL 36% hydrochloric acid was added, stirred at 70 DEG C for 30min, filtered, washed with deionized water for 3 times, dried in an oven at 70 DEG C for 10min, placed in a tube furnace, 6mL 30% potassium hydroxide solution was added, nitrogen was introduced, carbonized at 800 DEG C for 4h, cooled to room temperature, taken out, washed with deionized water for 3 times, dried in an oven at 70 DEG C for 10min, to obtain modified silicon carbide nanosheet;

[0108] A3. 2g graphene oxide was added into 120mL deionized water, stirred uniformly, 1.4g modified silicon carbide nanosheet was added, ultrasonically treated at 40KHz for 20min, filtered, washed with deionized water for 3 times, dried in an oven at 80 DEG C for 10min, to obtain composite material;

[0109] A4. 1g carboxymethyl cellulose was added into 85mL deionized water, stirred uniformly, 1.8g composite material was added, stirred for 30min, 2.5g sulfonated lignin and 3mL 36% hydrochloric acid were added, stirred and reacted at 60 DEG C for 20min, filtered, washed with deionized water for 3 times, dried in an oven at 70 DEG C for 10min, to obtain reinforcing filler.

[0110] Comparative example 3

[0111] A preparation method of a cemented carbide bearing for hard rock deep drilling, comprising the following preparation steps:

[0112] S1. tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler were mixed, and after ball milling, a mixture was obtained;

[0113] S2. the mixture was placed in a bearing mold for pressing into a preform;

[0114] S3. the preform was placed in a sintering furnace for sintering, and cooled to room temperature, and after treatment, grinding and polishing, a cemented carbide bearing was obtained.

[0115] Wherein, in step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:6:4:6:8:3:6;

[0116] In step S1, the ball mill is used, the ball-to-material ratio is 10:1, the rotation speed is 300 r / min, and the ball milling time is 20 h;

[0117] In step S2, the pressing pressure is 350 MPa and the pressing time is 40 s;

[0118] In step S3, the sintering temperature is 380° C., the sintering time is 4 h, the sintering pressure is 50 Pa, and the sintering is carried out in a nitrogen atmosphere with a nitrogen introduction rate of 60 mL / min.

[0119] The reinforcing filler is specifically prepared by the following steps:

[0120] A1. Add 0.4 g of tannic acid to 45 mL of ethanol and stir until completely dissolved. Then add 1.4 g of silicon carbide nanosheets and stir at 70°C for 40 minutes. Then add 1 g of nano-silicon nitride and continue stirring for 40 minutes. The mixture is filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain silicon carbide nanosheets loaded with nano-silicon nitride.

[0121] A2. 2 g of graphene oxide was added to 120 mL of deionized water and stirred. 1.4 g of silicon carbide nanosheets loaded with nano-silicon nitride was added and ultrasonicated at 40 kHz for 20 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 80°C for 10 min to obtain a composite material.

[0122] A3. Add 1 g of carboxymethyl cellulose to 85 mL of deionized water and stir well. Then add 1.8 g of the composite material and stir for 30 minutes. Then add 2.5 g of sulfonated lignin and 3 mL of 36% hydrochloric acid. Stir and react at 60°C for 20 minutes. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 minutes to obtain the reinforcing filler.

[0123] Comparative Example 4

[0124] A method for preparing a cemented carbide bearing for hard rock deep drilling comprises the following steps:

[0125] S1. The tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler are mixed and ball-milled to obtain a mixture;

[0126] S2. The mixture is placed in a bearing mold and pressed into a preform;

[0127] S3. Place the prefabricated body in a sintering furnace for sintering, cool to room temperature, and then post-process, grind, and polish to obtain a cemented carbide bearing.

[0128] Wherein, in step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:6:4:6:8:3:6;

[0129] In step S1, the ball mill is used, the ball-to-material ratio is 10:1, the rotation speed is 300 r / min, and the ball milling time is 20 h;

[0130] In step S2, the pressing pressure is 350 MPa and the pressing time is 40 s;

[0131] In step S3, the sintering temperature is 380° C., the sintering time is 4 h, the sintering pressure is 50 Pa, and the sintering is carried out in a nitrogen atmosphere with a nitrogen introduction rate of 60 mL / min.

[0132] The reinforcing filler is specifically prepared by the following steps:

[0133] A1. Add 0.4 g of tannic acid to 45 mL of ethanol and stir until completely dissolved. Then add 1.4 g of silicon carbide nanosheets and stir at 70°C for 40 minutes. Then add 1 g of nano-silicon nitride and continue stirring for 40 minutes. The mixture is filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain silicon carbide nanosheets loaded with nano-silicon nitride.

[0134] A2. 2 g of silicon nitride nanosheets loaded with silicon carbide nanosheets, 3 g of glucose, and 0.6 g of citric acid were added to 110 mL of ethanol. 2 mL of 36% hydrochloric acid was added and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 6 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain modified silicon carbide nanosheets.

[0135] A3. Add 1 g of carboxymethyl cellulose to 85 mL of deionized water and stir well. Then add 1.8 g of modified silicon carbide nanosheets and stir for 30 minutes. Then add 2.5 g of sulfonated lignin and 3 mL of 36% hydrochloric acid. Stir and react at 60°C for 20 minutes. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 minutes to obtain a reinforcing filler.

[0136] Comparative Example 5

[0137] A method for preparing a cemented carbide bearing for hard rock deep drilling comprises the following steps:

[0138] S1. The tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler are mixed and ball-milled to obtain a mixture;

[0139] S2. The mixture is placed in a bearing mold and pressed into a preform;

[0140] S3. Place the prefabricated body in a sintering furnace for sintering, cool to room temperature, and then post-process, grind, and polish to obtain a cemented carbide bearing.

[0141] Wherein, in step S1, the mass ratio of tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:6:4:6:8:3:6;

[0142] In step S1, the ball mill is used, the ball-to-material ratio is 10:1, the rotation speed is 300 r / min, and the ball milling time is 20 h;

[0143] In step S2, the pressing pressure is 350 MPa and the pressing time is 40 s;

[0144] In step S3, the sintering temperature is 380° C., the sintering time is 4 h, the sintering pressure is 50 Pa, and the sintering is carried out in a nitrogen atmosphere with a nitrogen introduction rate of 60 mL / min.

[0145] The reinforcing filler is specifically prepared by the following steps:

[0146] A1. Add 0.4 g of tannic acid to 45 mL of ethanol and stir until completely dissolved. Then add 1.4 g of silicon carbide nanosheets and stir at 70°C for 40 minutes. Then add 1 g of nano-silicon nitride and continue stirring for 40 minutes. The mixture is filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain silicon carbide nanosheets loaded with nano-silicon nitride.

[0147] A2. 2 g of silicon nitride nanosheets loaded with silicon carbide nanosheets, 3 g of glucose, and 0.6 g of citric acid were added to 110 mL of ethanol. 2 mL of 36% hydrochloric acid was added and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 6 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain modified silicon carbide nanosheets.

[0148] A3. 2 g of graphene oxide was added to 120 mL of deionized water and stirred. 1.4 g of modified silicon carbide nanosheets was added and ultrasonicated at 40 kHz for 20 min. The mixture was filtered, washed three times with deionized water, and dried in an oven at 80 ° C for 10 min to obtain a composite material.

[0149] A4. 1 g of carboxymethyl cellulose was added to 85 mL of deionized water, stirred uniformly, 1.8 g of the composite material was added, stirred for 30 min, filtered, washed with deionized water for 3 times, and dried in an oven at 70°C for 10 min to obtain the reinforced filler.

[0150] The performance of the cemented carbide bearings prepared in Examples 1-3 and Comparative Examples 1-5 was detected.

[0151] Mechanical property test: The yield strength and tensile strength of the cemented carbide bearings prepared above were determined according to GB / T228-2010 (Metallic materials - Tensile testing at ambient temperature).

[0152] Hardness (HRA) test: The hardness value of the cemented carbide bearings prepared above at room temperature was tested according to the standard GB / T3849.1-2015, and the cemented carbide bearings prepared above were placed at 1000°C, and the hardness value of the cemented carbide bearings at high temperature was tested.

[0153] The test results are shown in Table 1 below.

[0154] Table 1 Performance detection of cemented carbide bearings prepared in Examples 1-3 and Comparative Examples 1-5

[0155] Item Yield strength / MPa Tensile strength / MPa Room temperature hardness (HRA) Hardness at 1000°C (HRA) Example 1 1093 1108 65.9 55.3 Example 2 1105 1119 67.3 57.2 Example 3 1085 1097 63.7 53.1 Comparative Example 1 852 887 48.3 35.1 Comparative Example 2 786 793 45.7 31.7 Comparative Example 3 722 732 40.9 25.3 Comparative Example 4 766 771 43.7 28.6 Comparative Example 5 802 811 47.1 33.5

[0156] As can be seen from the data in Table 1, the cemented carbide bearings prepared in Examples 1-3 have high mechanical properties and temperature resistance.

[0157] In Comparative Example 1, the reinforced filler prepared by replacing tannic acid with an equal amount of ethanol was added to the cemented carbide bearing, and the mechanical properties and heat resistance decreased, which proved that the nano-silicon nitride adheres to the surface of the silicon carbide nanosheet through tannic acid, the nano-silicon nitride has high thermal conductivity, can improve the heat dissipation rate of the cemented carbide bearing, and is conducive to the formation of a composite layered material, improving the mechanical properties of the cemented carbide bearing.

[0158] In Comparative Example 2, the reinforced filler prepared by replacing nano-silicon nitride with silicon carbide nanosheet was added to the cemented carbide bearing, and the mechanical properties and heat resistance decreased, which proved that the nano-silicon nitride has high thermal conductivity, can improve the heat dissipation rate of the cemented carbide bearing, and can avoid the problem that as the drilling depth of the hard rock deep well increases, the temperature of the formation is high, and the heat is difficult to diffuse in the cemented carbide bearing, leading to degradation of the cemented carbide bearing and affecting the service life of the cemented carbide bearing.

[0159] In Comparative Example 3, the modified silicon carbide nanosheets are replaced with reinforcing fillers prepared by silicon carbide nanosheets loaded with nano-silicon nitride and added to the cemented carbide bearings. Its mechanical properties and heat resistance are reduced, which proves that the porous carbon structure synthesized on the surface of the silicon carbide nanosheets loaded with nano-silicon nitride can adsorb and fix nano-silicon nitride, thereby preventing the cemented carbide bearings from falling off when the nano-silicon nitride is used under high wear resistance and high pressure, causing cracks in the alloy bearings. During the sintering process, the carbon elements contained in the porous carbon can form a metal carbide reinforcement phase with the molten metal powder, filling the gaps in the alloy bearings, improving the density of the alloy bearings, and enhancing the mechanical strength of the alloy bearings.

[0160] In Comparative Example 4, the composite material is replaced with a reinforcing filler prepared from modified silicon carbide nanosheets and added to the cemented carbide bearing. Its mechanical properties and heat resistance are reduced, proving that the nano-silicon nitride and porous carbon between the layers of the layered composite material formed by intercalating the modified silicon carbide nanosheets into the graphene oxide layers serve as heat conduction channels, further enhancing the heat conduction path of the cemented carbide bearing and improving the heat dissipation performance. The formed layered composite material can absorb and reduce the stress generated by external forces, thereby enhancing the compressive strength of the alloy bearing.

[0161] In Comparative Example 5, a reinforcing filler prepared by replacing sulfonated lignin with carboxymethyl cellulose was added to a cemented carbide bearing, and its mechanical properties and heat resistance decreased, proving that the carboxymethyl cellulose was coated on the surface of the composite material and then reacted with the sulfonated lignin to form a cross-linked network structure coated on the surface of the composite material, which could be adsorbed to the surface of the alloy powder, thereby improving the density of the alloy powder. During the sintering process, the lignin-based cross-linked network structure was carbonized to form a dense cross-linked carbon network structure, which could supplement the carbon content in the alloy and avoid additional carbon loss during the preparation of the alloy bearing due to the high oxygen content, thereby affecting the mechanical properties of the alloy bearing.

[0162] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0163] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a cemented carbide bearing for hard rock deep drilling, characterized in that: The method comprises the following preparation steps: S1. The tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler are mixed and ball-milled to obtain a mixture; S2. The mixture is placed in a bearing mold and pressed into a preform; S3. The preform is placed in a sintering furnace, sintered, cooled to room temperature, and post-processed, ground, and polished to obtain a cemented carbide bearing; The reinforcing filler is obtained by mixing and reacting a composite material with sulfonated lignin after surface treatment with carboxymethyl cellulose; The composite material is obtained by adhering nano-silicon nitride to the surface of silicon carbide nanosheets through tannic acid, then mixing with glucose, carbonizing at high temperature, and intercalating between graphene oxide layers. The reinforcing filler is specifically prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add silicon carbide nanosheets and stir. Add nano-silicon nitride and continue stirring. Filter, wash, and dry to obtain nano-silicon nitride-loaded silicon carbide nanosheets. A2. The silicon carbide nanosheets loaded with nano-silicon nitride, glucose, and citric acid were added to ethanol, hydrochloric acid was added, stirred, filtered, washed, dried, potassium hydroxide solution was added, nitrogen was introduced, carbonized, cooled to room temperature, removed, washed, and dried to obtain modified silicon carbide nanosheets; A3. Graphene oxide was added to deionized water, stirred evenly, modified silicon carbide nanosheets were added, and after ultrasonic treatment, the mixture was filtered, washed, and dried to obtain a composite material; A4. Add carboxymethyl cellulose to deionized water and stir evenly. Add the composite material and stir. Add sulfonated lignin and hydrochloric acid. After stirring for reaction, filter, wash, and dry to obtain a reinforcing filler.

2. The method for preparing a cemented carbide bearing for hard rock deep drilling according to claim 1, characterized in that: In step A1, the ratio of the tannic acid, ethanol, silicon carbide nanosheets and nano-silicon nitride is (0.2-0.4) g: (35-45) mL: (1-1.4) g: (0.6-1) g.

3. The method for preparing a cemented carbide bearing for hard rock deep drilling according to claim 1, characterized in that: In step A2, the amount ratio of the silicon carbide nanosheets loaded with nano-silicon nitride, glucose, citric acid, ethanol, hydrochloric acid and potassium hydroxide solution is (1-2) g: (2-3) g: (0.4-0.6) g: (90-110) mL: (1-2) mL: (4-6) mL.

4. The method for preparing a cemented carbide bearing for hard rock deep drilling according to claim 1, characterized in that: In step A3, the ratio of the graphene oxide, deionized water, and modified silicon carbide nanosheets is (1-2) g: (80-120) mL: (1-1.4) g.

5. The method for preparing a cemented carbide bearing for hard rock deep drilling according to claim 1, characterized in that: In step A4, the ratio of the carboxymethyl cellulose, deionized water, composite material, sulfonated lignin and hydrochloric acid is (0.6-1) g: (75-85) mL: (1.4-1.8) g: (1.5-2.5) g: (1-3) mL.

6. The method for preparing a cemented carbide bearing for hard rock deep drilling according to claim 1, characterized in that: In step S1, the mass ratio of the tungsten carbide powder, aluminum powder, cobalt powder, nickel powder, iron powder, graphite powder and reinforcing filler is 100:(5-6):(2-4):(4-6):(6-8):(1-3):(5-6); The ball milling is performed using a ball mill with a ball-to-material ratio of (8-10):1, a rotation speed of 200-300 r / min, and a ball milling time of 15-20 h.

7. The method for preparing a cemented carbide bearing for hard rock deep drilling according to claim 1, characterized in that: In step S2, the pressing pressure is 300-350 MPa, and the pressing time is 30-40 s.

8. The method for preparing a cemented carbide bearing for hard rock deep drilling according to claim 1, characterized in that: In step S3, the sintering temperature is 1300-1380°C, the sintering time is 2-4 hours, the sintering pressure is 40-50 Pa, and the sintering is carried out in a nitrogen atmosphere with a nitrogen introduction rate of 50-60 mL / min.

9. A cemented carbide bearing produced by the method for producing a cemented carbide bearing for hard rock deep drilling according to any one of claims 1 to 8.