A grinding wheel based on high wear-resistant diamond micro powder and its preparation process

Abstract

This invention relates to the field of diamond grinding wheel technology, specifically to a grinding wheel based on high-wear-resistant diamond micropowder and its preparation process, comprising the following steps: Step 1, diamond modification: diamond is subjected to heat treatment, ion implantation, and metal plating sequentially to obtain modified diamond; Step 2, grinding wheel preparation: the modified diamond is mixed with a binder, pressed, and sintered to obtain the grinding wheel. This invention prepares modified diamond by sequentially subjecting it to water-gas reaction, silicon and titanium ion implantation, and vacuum chromium plating. This improves the wear resistance, strength, and oxidation resistance of diamond, enhances the bonding strength between diamond and the binder, and improves the electrical and thermal conductivity of diamond, facilitating subsequent processes. The diamond bonds to the binder through a surface layer, further improving the wear resistance and mechanical properties of the prepared grinding wheel.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of diamond grinding wheels, in particular to a grinding wheel based on high-wear-resistance diamond micro powder and a preparation process thereof. BACKGROUND

[0002] The grinding wheel, as a kind of fixed mold, is formed by binding agent and abrasive, has certain strength, is most widely used in the application of the grinding tool and is used most. Diamond is one kind of abrasive, compared with ordinary abrasive, has higher hardness, wear resistance, micro-blade and heat conduction performance, so that it can be applied to the metal grinding field. The sintering temperature of some existing diamond grinding wheels mixed with ceramic binder is high, which is easy to cause graphitization of diamond, so that the grinding performance of the prepared diamond grinding wheel is negatively affected, the bonding strength between the binder and the diamond is low, which hinders the use performance, and also causes certain harm in use safety. Therefore, the application provides a grinding wheel based on high-wear-resistance diamond micro powder and a preparation process thereof. SUMMARY

[0003] The application aims to provide a grinding wheel based on high-wear-resistance diamond micro powder and a preparation process thereof to solve the problems in the background.

[0004] In order to solve the above technical problems, the application provides the following technical scheme: a preparation process of a grinding wheel based on high-wear-resistance diamond micro powder, which comprises the following process steps:

[0005] Step 1, modification of diamond:

[0006] The diamond is sequentially subjected to heat treatment, ion implantation and metal plating to obtain modified diamond;

[0007] Step 2, preparation of the grinding wheel:

[0008] The modified diamond is mixed with a binder, pressed, sintered to obtain the grinding wheel.

[0009] Further, the step 1 comprises the following process:

[0010] The diamond is placed in a heating furnace, heated to 700-800 DEG C, water vapor is introduced, the flow rate is 5*10 -4 m 3 / s, the reaction time is 30-120 min to obtain diamond A;

[0011] The diamond A is subjected to ion implantation, sequentially silicon ion implantation and titanium ion implantation;

[0012] The process of silicon ion implantation is as follows: the implantation source is silicon, the ion beam current intensity is 2.5-7.5 mu A / cm 2 , the implantation amount is 2.0*10 16~1.0×10 17 ion / cm 2 Vacuum degree 1.0×10 -3 ~6×10 -2 Pa;

[0013] The titanium ion implantation process is as follows: the implantation source is titanium, and the ion beam current intensity is 4.5–8.5 μA / cm. 2 Injection volume 3.0 × 10 17 ~5.0×10 17 ion / cm 2 Vacuum degree 3.0×10 -3 ~6×10 -2 Pa; forms an injection layer to obtain diamond B;

[0014] Diamond B is mixed with chromium powder, wetted with anhydrous ethanol, placed in a mold and sealed, and vacuum-deposited to form a metallic chromium layer, thus obtaining modified diamond with a surface layer.

[0015] Furthermore, the process conditions for vacuum coating are: temperature 850–900℃, holding time 200–240 min;

[0016] The mass ratio of diamond B to chromium powder is 10:(3-5).

[0017] Diamond: 3000 mesh, sourced from Henan Yellow River Whirlwind Co., Ltd.

[0018] Chromium powder: electrolytic method, particle size 1μm, sourced from Zhejiang Yamei Nanotechnology Co., Ltd.

[0019] In the above technical solution, at high temperature, diamond reacts with water vapor to produce water gas, generating carbon monoxide and hydrogen gas, which etch the diamond surface and eliminate sp. 2 Carbon, CH bonds, and unstable graphite clusters increase the number of C=O bonds that facilitate interfacial bonding; pits appear on the

[100] and

[111] crystal planes of diamond, and gradually expand with increasing processing temperature, allowing the diamond obtained after treatment to increase its surface area while maintaining its excellent mechanical properties. In subsequent processes, this can improve the surface interfacial bonding of diamond, increase its contact area with the prepared surface layer and binder, improve bonding strength, and promote the extension of grinding wheel service life and the improvement of strength and wear resistance.

[0020] Ion beam implantation is used to sequentially ionize silicon and titanium, accelerate them under an electric field to obtain high energy, and then inject them into the diamond surface. This fills and improves the surface defects of the diamond, makes its crystal lattice arrangement more regular, increases its crystallinity, and promotes the densification of the diamond surface structure. Silicon, entering the diamond lattice, can form covalent bonds with it and react with titanium metal at the interface to form titanium-silicon compounds, enhancing the adhesion between the diamond surface and the metal surface layer, and improving the bonding strength between the modified diamond and the binder. Titanium reacts with diamond at the interface to form a dense titanium carbide interface shell, maintaining the strength of the binder after sintering, thereby improving the wear resistance, strength, and oxidation resistance of the diamond, and improving the bonding strength between the diamond and the binder. Simultaneously, the introduction of silicon reduces the reaction between titanium and diamond, forming titanium silicon carbide, which prevents the titanium carbide interface layer between diamond particles from contacting and merging, thus facilitating the dispersion of the modified diamond.

[0021] Then, the diamond obtained in the previous step is vacuum coated to form a layer of metallic chromium on the diamond surface. The injection layer serves as an intermediate layer, which can alleviate the difference in thermal expansion between the diamond and metallic chromium, promote the dense coating of metallic chromium on the diamond surface, enhance the bond between the modified diamond and the binder, and improve the holding force of the diamond in the manufactured grinding wheel. It can also improve the electrical and thermal conductivity of the diamond, which is beneficial to the subsequent processes. This allows the diamond to bond with the binder through the surface layer, which can further improve the wear resistance and mechanical properties of the manufactured grinding wheel.

[0022] Furthermore, the mixing process of the diamond and the binder is as follows:

[0023] Modified diamond, hollow alumina microspheres, yttrium oxide, and anhydrous ethanol were mixed and ultrasonically stirred for 20–30 min. Sodium dodecylbenzenesulfonate was added and ultrasonically stirred for 50–60 min. Tetraethyl orthosilicate was added and ultrasonically stirred for 160–200 min. The pH of the system was adjusted to 4.0–4.5 using 1M nitric acid. Acetylacetone was added and ultrasonically stirred until clear to obtain liquid C.

[0024] Deionized water and anhydrous ethanol were mixed, and aluminum nitrate, boric acid and sodium nitrate were added. The mixture was stirred until homogeneous to obtain liquid D.

[0025] Liquid D was slowly added to liquid C and stirred at 70–78°C until it became gel-like. It was then aged at room temperature for 24 hours. After drying at 210–250°C for 8–24 hours, it was oxidized, ball-milled, and passed through a 200-mesh sieve. Finally, it was calcined to obtain a mixture of modified diamond and binder.

[0026] Furthermore, the ultrasonic stirring process conditions are: 40–50 kHz, 300–360 r / min.

[0027] Furthermore, the oxidation is performed using micro-arc oxidation, with process conditions of: current density 8–10 A / dm³. 2 Frequency 500-700Hz, duty cycle 10-20%, oxidation time 20-22min, electrolyte temperature 20-30℃;

[0028] The electrolyte consists of 50 g / L sodium phosphate, 4 g / L sodium tungstate, and 30 g / L sodium hexametaphosphate.

[0029] Furthermore, the calcination process conditions are as follows: calcination at 120–150℃ for 60 min, calcination at 180–200℃ for 60 min, calcination at 400–420℃ for 60 min, and calcination at 550–570℃ for 360 min.

[0030] Furthermore, the mixture is prepared from the following components by mass: 100 parts modified diamond, 3-9 parts hollow alumina microspheres, 1 part sodium dodecylbenzenesulfonate, 7-12 parts tetraethyl orthosilicate, 18-26 parts aluminum nitrate, 40-50 parts boric acid, 8-12 parts sodium nitrate, and 2.0-2.5 parts yttrium oxide.

[0031] In liquid C, the ratio of modified diamond to anhydrous ethanol is 0.25 g / 100 mL;

[0032] In solution D, the ratio of aluminum nitrate, deionized water, and anhydrous ethanol is 5g:100mL:100mL.

[0033] Furthermore, in step 2, the pressing is cold pressing, and the process conditions are: pressure 20-25 MPa, duration 30-60 min; and then it is dried at 60-80℃ for 10-12 h.

[0034] Furthermore, in step 2, the sintering process conditions are: sintering temperature 670-750℃, holding time 60-90min; followed by furnace cooling.

[0035] Hollow alumina microspheres: particle size 0.2mm, sourced from Zhengzhou Kun'ao Refractory Materials Co., Ltd.

[0036] Yttrium oxide: nanoscale, sourced from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0037] In the above technical solution, modified diamond is mixed with binder raw materials and dried. The aluminum nitrate in the raw materials is decomposed and then oxidized to oxidize the metallic chromium layer on the surface of the modified diamond. The generated chromium oxide can promote the transformation of the crystalline phase of aluminum oxide to the α phase, forming a multiphase ceramic of chromium oxide and aluminum oxide, which can improve the hardness and wear resistance of the prepared binder.

[0038] Then, a co-pressing and sintering process is performed, mixing the binder raw materials with modified diamond and sintering to form an oxide ceramic. This oxide ceramic possesses good elasticity and toughness, contributing to improved impact resistance of the manufactured grinding wheel. The addition of the rare earth element oxide yttrium oxide enhances oxygen exchange efficiency during the oxidation process, accelerates the formation of the chromium oxide film, promotes film densification, and forms a hard film layer, thereby improving the grinding wheel's strength and wear resistance. Hollow alumina microspheres are also added to the binder raw materials. After sintering, the manufactured grinding wheel forms pores, which reduces grinding heat, facilitates chip removal, prevents wheel clogging, and improves grinding performance.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] 1. The present invention discloses a process for preparing a grinding wheel based on high wear-resistant diamond micropowder. Modified diamond is prepared by sequentially subjecting diamond to a water-gas reaction, silicon and titanium ion implantation, and vacuum chromium plating. This process improves the wear resistance, strength, and oxidation resistance of the diamond, enhances the bonding strength between the diamond and the binder, and improves the electrical and thermal conductivity of the diamond, facilitating subsequent processes. The diamond adheres to the binder through a surface layer, further improving the wear resistance and mechanical properties of the prepared grinding wheel.

[0041] 2. The present invention provides a process for preparing a grinding wheel based on high wear-resistant diamond micro powder. The process involves mixing and drying modified diamond with binder raw materials, decomposing aluminum nitrate in the raw materials to form aluminum oxide, and then oxidizing the metallic chromium layer on the surface of the modified diamond. The generated chromium oxide can promote the transformation of the crystalline phase of aluminum oxide to the α phase, forming a multiphase ceramic of chromium oxide and aluminum oxide, thereby improving the hardness and wear resistance of the prepared binder. Detailed Implementation

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] In the following specific implementation,

[0044] Diamond: 3000 mesh, sourced from Henan Yellow River Whirlwind Co., Ltd.

[0045] Chromium powder: electrolytic method, particle size 1μm, sourced from Zhejiang Yamei Nanotechnology Co., Ltd.

[0046] Hollow alumina microspheres: particle size 0.2mm, sourced from Zhengzhou Kun'ao Refractory Materials Co., Ltd.

[0047] Yttrium oxide: nanoscale, sourced from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0048] The electrolyte consists of 50 g / L sodium phosphate, 4 g / L sodium tungstate, and 30 g / L sodium hexametaphosphate.

[0049] Example 1: A process for preparing a grinding wheel based on high wear-resistant diamond micro powder, comprising the following steps:

[0050] Step 1, Modification of diamond:

[0051] The diamond was placed in a heating furnace and heated to 700°C. Steam was then introduced at a flow rate of 5 × 10⁻⁶. -4 m 3 / s, react for 120min to obtain diamond A;

[0052] Diamond A was subjected to ion implantation, and silicon ion implantation was performed: the implantation source was silicon, and the ion beam current intensity was 2.5 μA / cm. 2 Injection volume 2.0 × 10 16 ion / cm 2 Vacuum degree 1.0×10 -3 Pa; Titanium ion implantation: The implantation source is titanium, and the ion beam current intensity is 4.5 μA / cm. 2 Injection volume 3.0 × 10 17 ion / cm 2 Vacuum degree 3.0×10 -3 Pa; forms an injection layer to obtain diamond B;

[0053] Diamond B was mixed with chromium powder at a mass ratio of 10:3. Anhydrous ethanol was added for wetting, the mixture was placed in a mold and sealed, and vacuum coating was performed. The process conditions were: temperature 850℃, holding time 200min, to form a metallic chromium layer and obtain modified diamond with a surface layer.

[0054] Step 2, Grinding wheel preparation:

[0055] Modified diamond, hollow alumina microspheres, yttrium oxide, and anhydrous ethanol were mixed and ultrasonically stirred for 20 min. Sodium dodecylbenzenesulfonate was added and ultrasonically stirred for 50 min. Tetraethyl orthosilicate was added and ultrasonically stirred for 160 min. The pH of the system was adjusted to 4.0 using 1M nitric acid. Acetylacetone was added and ultrasonically stirred until clear to obtain liquid C. The ultrasonic stirring conditions were: 40 kHz, 300 r / min; the ratio of modified diamond to anhydrous ethanol was 0.25 g / 100 mL.

[0056] Mix deionized water and anhydrous ethanol, add aluminum nitrate, boric acid and sodium nitrate, stir well to obtain liquid D; the ratio of aluminum nitrate, deionized water and anhydrous ethanol is 5g:100mL:100mL.

[0057] Liquid D was slowly added to liquid C and placed at 70°C, stirred until gel-like, and aged at room temperature for 24 hours; then dried at 210°C for 24 hours; micro-arc oxidation was performed under the following conditions: current density 8 A / dm³. 2 The oxidation process was carried out at a frequency of 500 Hz, a duty cycle of 10%, an oxidation time of 20 min, and an electrolyte temperature of 20 ℃. The mixture was ball-milled and passed through a 200-mesh sieve. Calcination was then performed under the following conditions: calcination at 120 ℃ for 60 min, 180 ℃ for 60 min, 400 ℃ for 60 min, and 550 ℃ for 360 min, yielding a mixture of modified diamond and a binder. The mixture was prepared from the following mass components: 100 parts modified diamond, 3 parts hollow alumina microspheres, 1 part sodium dodecylbenzenesulfonate, 7 parts tetraethyl orthosilicate, 18 parts aluminum nitrate, 40 parts boric acid, 8 parts sodium nitrate, and 2.0 parts yttrium oxide.

[0058] The process involves cold pressing, with a pressure of 20 MPa and a duration of 60 min; followed by drying at 60°C for 12 h; sintering, with a sintering temperature of 670°C and a holding time of 90 min; and then cooling in the furnace to obtain the grinding wheel.

[0059] Example 2: A process for preparing a grinding wheel based on high wear-resistant diamond micro powder, comprising the following steps:

[0060] Step 1, Modification of diamond:

[0061] The diamond was placed in a heating furnace and heated to 750°C. Steam was then introduced at a flow rate of 5 × 10⁻⁶. -4 m 3 / s, react for 75min, to obtain diamond A;

[0062] Diamond A was subjected to ion implantation, and silicon ion implantation was performed: the implantation source was silicon, and the ion beam current intensity was 2.5–7.5 μA / cm. 2 Injection volume 6.0 × 10 16 ion / cm 2 Vacuum degree 3×10 -2 Pa; Titanium ion implantation: The implantation source is titanium, and the ion beam current intensity is 6.5 μA / cm. 2 Injection volume 4.0 × 10 17 ion / cm 2 Vacuum degree 3×10 -2 Pa; forms an injection layer to obtain diamond B;

[0063] Diamond B was mixed with chromium powder at a mass ratio of 10:4. Anhydrous ethanol was added for wetting, the mixture was placed in a mold and sealed, and vacuum coating was performed. The process conditions were: temperature 875℃, holding time 220min, to form a metallic chromium layer and obtain modified diamond with a surface layer.

[0064] Step 2, Grinding wheel preparation:

[0065] Modified diamond, hollow alumina microspheres, yttrium oxide, and anhydrous ethanol were mixed and ultrasonically stirred for 25 min. Sodium dodecylbenzenesulfonate was added and ultrasonically stirred for 55 min. Tetraethyl orthosilicate was added and ultrasonically stirred for 180 min. The pH of the system was adjusted to 4.2 using 1M nitric acid. Acetylacetone was added and ultrasonically stirred until clear to obtain liquid C. The ultrasonic stirring conditions were: 45 kHz, 330 r / min; the ratio of modified diamond to anhydrous ethanol was 0.25 g / 100 mL.

[0066] Mix deionized water and anhydrous ethanol, add aluminum nitrate, boric acid and sodium nitrate, stir well to obtain liquid D; the ratio of aluminum nitrate, deionized water and anhydrous ethanol is 5g:100mL:100mL.

[0067] Liquid D was slowly added to liquid C and placed at 75°C, stirred until gel-like, and aged at room temperature for 24 hours; then dried at 210–250°C for 16 hours; micro-arc oxidation was performed under the following conditions: current density 9 A / dm³. 2 The oxidation process was carried out at a frequency of 600 Hz, a duty cycle of 15%, an oxidation time of 21 min, and an electrolyte temperature of 25 ℃. The mixture was ball-milled and passed through a 200-mesh sieve. Calcination was then performed under the following conditions: calcination at 135 ℃ for 60 min, 190 ℃ for 60 min, 410 ℃ for 60 min, and 560 ℃ for 360 min, yielding a mixture of modified diamond and a binder. The mixture was prepared from the following mass components: 100 parts modified diamond, 6 parts hollow alumina microspheres, 1 part sodium dodecylbenzenesulfonate, 9 parts tetraethyl orthosilicate, 22 parts aluminum nitrate, 45 parts boric acid, 10 parts sodium nitrate, and 2.2 parts yttrium oxide.

[0068] The process involves cold pressing, with a pressure of 22 MPa and a duration of 45 min; followed by drying at 70°C for 11 h; sintering, with a sintering temperature of 710°C and a holding time of 75 min; and then cooling in the furnace to obtain the grinding wheel.

[0069] Example 3: A process for preparing a grinding wheel based on high wear-resistant diamond micro powder, comprising the following steps:

[0070] Step 1, Modification of diamond:

[0071] The diamond was placed in a heating furnace and heated to 800°C. Steam was then introduced at a flow rate of 5 × 10⁻⁶. -4 m 3 / s, react for 30min to obtain diamond A;

[0072] Diamond A was subjected to ion implantation, and silicon ion implantation was performed: the implantation source was silicon, and the ion beam current intensity was 7.5 μA / cm. 2 Injection volume 1.0 × 10 17 ion / cm 2 Vacuum degree 6×10 -2 Pa; Titanium ion implantation: The implantation source is titanium, and the ion beam current intensity is 8.5 μA / cm. 2 Injection volume 5.0 × 10 17 ion / cm 2 Vacuum degree 6×10 -2 Pa; forms an injection layer to obtain diamond B;

[0073] Diamond B was mixed with chromium powder at a mass ratio of 10:5. Anhydrous ethanol was added for wetting, the mixture was placed in a mold and sealed, and vacuum coating was performed. The process conditions were: temperature 900℃, holding time 200min, to form a metallic chromium layer and obtain modified diamond with a surface layer.

[0074] Step 2, Grinding wheel preparation:

[0075] Modified diamond, hollow alumina microspheres, yttrium oxide, and anhydrous ethanol were mixed and ultrasonically stirred for 30 min. Sodium dodecylbenzenesulfonate was added and ultrasonically stirred for 60 min. Tetraethyl orthosilicate was added and ultrasonically stirred for 200 min. The pH of the system was adjusted to 4.5 using 1M nitric acid. Acetylacetone was added and ultrasonically stirred until clear to obtain liquid C. The ultrasonic stirring conditions were: 50 kHz, 360 r / min; the ratio of modified diamond to anhydrous ethanol was 0.25 g / 100 mL.

[0076] Mix deionized water and anhydrous ethanol, add aluminum nitrate, boric acid and sodium nitrate, stir well to obtain liquid D; the ratio of aluminum nitrate, deionized water and anhydrous ethanol is 5g:100mL:100mL.

[0077] Liquid D was slowly added to liquid C and placed at 78°C, stirred until gel-like, and aged at room temperature for 24 hours; then dried at 250°C for 8 hours; micro-arc oxidation was performed under the following conditions: current density 10 A / dm³. 2 The oxidation process was carried out at a frequency of 700 Hz, a duty cycle of 20%, an oxidation time of 22 min, and an electrolyte temperature of 30 ℃. The mixture was ball-milled and passed through a 200-mesh sieve. Calcination was performed under the following conditions: calcination at 150 ℃ for 60 min, calcination at 200 ℃ for 60 min, calcination at 420 ℃ for 60 min, and calcination at 570 ℃ for 360 min, yielding a mixture of modified diamond and a binder. The mixture was prepared from the following mass components: 100 parts modified diamond, 9 parts hollow alumina microspheres, 1 part sodium dodecylbenzenesulfonate, 12 parts tetraethyl orthosilicate, 26 parts aluminum nitrate, 50 parts boric acid, 12 parts sodium nitrate, and 2.5 parts yttrium oxide.

[0078] The process involves cold pressing, with a pressure of 25 MPa and a duration of 30 min; followed by drying at 80°C for 10 h; sintering, with a sintering temperature of 750°C and a holding time of 60 min; and then cooling in the furnace to obtain the grinding wheel.

[0079] Comparative Example 1: A process for preparing a grinding wheel based on high wear-resistant diamond micro powder, comprising the following steps:

[0080] Step 1, Modification of diamond:

[0081] The diamond was placed in a heating furnace and heated to 700°C. Steam was then introduced at a flow rate of 5 × 10⁻⁶. -4 m 3 / s, react for 120min to obtain diamond A;

[0082] Diamond A was subjected to ion implantation, and silicon ion implantation was performed: the implantation source was silicon, and the ion beam current intensity was 2.5 μA / cm. 2 Injection volume 2.0 × 10 16 ion / cm 2 Vacuum degree 1.0×10 -3 Pa; Titanium ion implantation: The implantation source is titanium, and the ion beam current intensity is 4.5 μA / cm. 2 Injection volume 3.0 × 10 17 ion / cm 2 Vacuum degree 3.0×10 -3 Pa; forms an injection layer to obtain modified diamond with a surface layer;

[0083] Step 2 is the same as in Example 1, and a grinding wheel is obtained.

[0084] Comparative Example 2: A process for preparing a grinding wheel based on high wear-resistant diamond micro powder, comprising the following steps:

[0085] Step 1, Modification of diamond:

[0086] The diamond was placed in a heating furnace and heated to 700°C. Steam was then introduced at a flow rate of 5 × 10⁻⁶. -4 m 3 / s, react for 120min to obtain diamond A;

[0087] Diamond A was mixed with chromium powder, and the mass ratio of diamond B to chromium powder was 10:3. Anhydrous ethanol was added to wet the mixture, and the mixture was placed in a mold and sealed. Vacuum coating was then performed under the following conditions: temperature 850℃, holding time 200min, to form a metallic chromium layer and obtain modified diamond with a surface layer.

[0088] Step 2 is the same as in Example 1, and a grinding wheel is obtained.

[0089] Comparative Example 3: A process for preparing a grinding wheel based on high wear-resistant diamond micro powder, comprising the following process steps:

[0090] Diamond, hollow alumina microspheres, yttrium oxide, and anhydrous ethanol were mixed and ultrasonically stirred for 20 min. Sodium dodecylbenzenesulfonate was added and ultrasonically stirred for 50 min. Tetraethyl orthosilicate was added and ultrasonically stirred for 160 min. The pH of the system was adjusted to 4.0 using 1M nitric acid. Acetylacetone was added and ultrasonically stirred until clear to obtain liquid C. The ultrasonic stirring conditions were: 40 kHz, 300 r / min; the ratio of modified diamond to anhydrous ethanol was 0.25 g / 100 mL.

[0091] Mix deionized water and anhydrous ethanol, add aluminum nitrate, boric acid and sodium nitrate, stir well to obtain liquid D; the ratio of aluminum nitrate, deionized water and anhydrous ethanol is 5g:100mL:100mL.

[0092] Liquid D was slowly added to liquid C and placed at 70°C, stirred until gel-like, and aged at room temperature for 24 hours; then dried at 210°C for 24 hours; micro-arc oxidation was performed under the following conditions: current density 8 A / dm³. 2 The oxidation process was carried out at a frequency of 500 Hz, a duty cycle of 10%, an oxidation time of 20 min, and an electrolyte temperature of 20 ℃. The mixture was ball-milled and passed through a 200-mesh sieve. Calcination was performed under the following conditions: calcination at 120 ℃ for 60 min, 180 ℃ for 60 min, 400 ℃ for 60 min, and 550 ℃ for 360 min, yielding a mixture of modified diamond and a binder. The mixture was prepared from the following mass components: 100 parts diamond, 3 parts hollow alumina microspheres, 1 part sodium dodecylbenzenesulfonate, 7 parts tetraethyl orthosilicate, 18 parts aluminum nitrate, 40 parts boric acid, 8 parts sodium nitrate, and 2.0 parts yttrium oxide.

[0093] The process involves cold pressing, with a pressure of 20 MPa and a duration of 60 min; followed by drying at 60°C for 12 h; sintering, with a sintering temperature of 670°C and a holding time of 90 min; and then cooling in the furnace to obtain the grinding wheel.

[0094] Comparative Example 4: A process for preparing a grinding wheel based on high wear-resistant diamond micro powder, comprising the following steps:

[0095] Diamond and anhydrous ethanol were mixed and ultrasonically stirred for 20 min; sodium dodecylbenzenesulfonate was added and ultrasonically stirred for 50 min; tetraethyl orthosilicate was added and ultrasonically stirred for 160 min; the pH of the system was adjusted to 4.0 using 1M nitric acid; acetylacetone was added and ultrasonically stirred until clear to obtain liquid C; the ultrasonic stirring conditions were: 40 kHz, 300 r / min; the ratio of modified diamond to anhydrous ethanol was 0.25 g / 100 mL;

[0096] Mix deionized water and anhydrous ethanol, add aluminum nitrate, boric acid and sodium nitrate, stir well to obtain liquid D; the ratio of aluminum nitrate, deionized water and anhydrous ethanol is 5g:100mL:100mL.

[0097] Liquid D was slowly added to liquid C and placed at 70°C, stirred until gel-like, and aged at room temperature for 24 hours; then dried at 210°C for 24 hours; micro-arc oxidation was performed under the following conditions: current density 8 A / dm³. 2 The oxidation process was carried out at a frequency of 500 Hz, a duty cycle of 10%, an oxidation time of 20 min, and an electrolyte temperature of 20 ℃. The mixture was ball-milled and passed through a 200-mesh sieve. Calcination was then performed under the following conditions: calcination at 120 ℃ for 60 min, 180 ℃ for 60 min, 400 ℃ for 60 min, and 550 ℃ for 360 min, yielding a mixture of modified diamond and a binder. The mixture was prepared from the following mass components: 100 parts diamond, 1 part sodium dodecylbenzenesulfonate, 7 parts tetraethyl orthosilicate, 18 parts aluminum nitrate, 40 parts boric acid, and 8 parts sodium nitrate.

[0098] The process involves cold pressing, with a pressure of 20 MPa and a duration of 60 min; followed by drying at 60°C for 12 h; sintering, with a sintering temperature of 670°C and a holding time of 90 min; and then cooling in the furnace to obtain the grinding wheel.

[0099] Experiment: Grinding wheels obtained in Examples 1-3 and Comparative Examples 1-4 were used to prepare samples. Their performance was tested and the test results were recorded.

[0100] Bending strength test: GB / T 10700 was used as the reference standard. A universal testing machine was used to test the bending strength of the specimen using the three-point bending method. The loading speed of the indenter was 0.5 mm / min, and the test span was 20 mm.

[0101] Bond strength test: Modified diamond and dried binder raw material are loaded into a mold and placed at the left and right ends of the mold respectively and in contact. Then, oxidation, calcination, pressing and sintering processes are carried out to obtain a sample. Three-point bending resistance test is performed on the contact surface between diamond and binder in the sample, and the data obtained is recorded as the bond strength.

[0102] Grinding performance test: A reciprocating friction and wear tester was used. The friction surface size of the sample was 40mm×10mm. The friction object was cast iron. The friction load was 1.5kg. The friction time was 30min. The working speed was 20m / min. The ratio of the wear mass of cast iron to that of the sample was calculated and recorded as the wear ratio.

[0103] Flexural strength (MPa) Bond strength (MPa) Abrasion ratio Example 1 983 95 43.8 Example 2 967 93 44.8 Example 3 950 90 46.1 Comparative Example 1 971 84 37.3 Comparative Example 2 964 81 40.6 Comparative Example 3 882 73 32.9 Comparative Example 4 905 69 28.6

[0104] Based on the data in the table above, the following conclusions can be clearly drawn:

[0105] The grinding wheels obtained in Examples 1-3 are compared with those obtained in Comparative Examples 1-4. The test results show that...

[0106] Compared with the comparative examples, the grinding wheels obtained in Examples 1-3 have higher bending strength, bonding strength and wear ratio data, which fully demonstrates that the present invention has achieved the improvement of the bonding strength between diamond and the binder, the strength of the grinding wheel and the wear resistance.

[0107] Compared to Example 1, the modified diamond in Comparative Example 1 was obtained through heat treatment and ion implantation; the modified diamond in Comparative Example 2 was obtained through heat treatment and vacuum chromium plating. The diamond in Comparative Example 3 was not modified; based on Comparative Example 3, the binder raw material in Comparative Example 4 did not contain hollow alumina microspheres or yttrium oxide. The grinding wheels obtained in Comparative Examples 1-4 showed a decrease in bending strength, bonding strength, and wear ratio. This indicates that the modification of diamond, the mixing process with the binder, and the setting of the required components in this invention can promote the improvement of the bonding strength between diamond and the binder and improve the strength and wear resistance of the resulting grinding wheels.

[0108] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process method article or apparatus.

[0109] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for the preparation of a grinding wheel based on high wear resistance diamond micro powder, characterized by: The preparation process comprises the following steps: Step 1: modification of diamond The diamond is sequentially subjected to heat treatment, ion implantation, and metal plating to obtain modified diamond; Step 2: preparation of grinding wheel The modified diamond is mixed with a binder, pressed, and sintered to obtain a grinding wheel; The step 1 comprises the following process: The diamond is placed in a heating furnace, heated to 700-800℃, water vapor is introduced, the flow rate is 5x10 -4 m 3 / s, the reaction is carried out for 30-120 min, to obtain diamond A; The diamond A is subjected to ion implantation, sequentially silicon ion implantation and titanium ion implantation; The process of silicon ion implantation is as follows: the implantation source is silicon, ion beam intensity is 2.5-7.5 μA / cm 2 , implantation amount is 2.0×10 16 -1.0×10 17 ion / cm 2 , vacuum degree is 1.0×10 -3 -6×10 -2 Pa; The process of titanium ion implantation is as follows: the implantation source is titanium, the ion beam intensity is 4.5-8.5 μA / cm 2 , the implantation amount is 3.0×10 17 -5.0×10 17 ion / cm 2 , the vacuum degree is 3.0×10 -3 -6×10 -2 Pa; the implantation layer is formed to obtain diamond B; The diamond B is mixed with chromium powder, wetted with anhydrous ethanol, sealed in a mold, and subjected to vacuum plating to form a metal chromium layer, thereby obtaining modified diamond with a surface layer; In the step 2, the mixing process of diamond and binder is as follows: The modified diamond, hollow alumina microspheres, yttrium oxide, and anhydrous ethanol are mixed and ultrasonically stirred for 20-30 min; sodium dodecylbenzenesulfonate is added and ultrasonically stirred for 50-60 min; tetraethyl orthosilicate is added and ultrasonically stirred for 160-200 min; the pH of the system is adjusted to 4.0-4.5 using 1M nitric acid; acetylacetone is added and ultrasonically stirred until clear to obtain liquid C; Deionized water and anhydrous ethanol are mixed, and aluminum nitrate, boric acid, and sodium nitrate are added and stirred uniformly to obtain liquid D; Liquid D is slowly added to liquid C, and stirred at a temperature of 70-78°C until gel-like, and aged at room temperature for 24 h; dried at a temperature of 210-250°C for 8-24 h; oxidized, ball milled, and sieved through a 200 mesh sieve; calcined to obtain a mixture of modified diamond and binder.

2. The process for manufacturing a grinding wheel based on high abrasion resistance diamond micro powder according to claim 1, characterized in that: The process conditions for vacuum plating are as follows: temperature 850-900°C, and holding time 200-240 min. The mass ratio of diamond B to chromium powder is 10:(3-5).

3. The process for manufacturing a grinding wheel based on high abrasion resistance diamond micro powder as claimed in claim 1, wherein: The process conditions of the oxidation are: current density 8-10 A / dm 2 , frequency 500-700 Hz, duty cycle 10-20%, oxidation time 20-22 min, electrolyte temperature 20-30 °C; The electrolyte comprises 50 g / L sodium phosphate, 4 g / L sodium tungstate, and 30 g / L sodium hexametaphosphate.

4. The process for manufacturing a grinding wheel based on high abrasion resistance diamond micro powder as claimed in claim 1, wherein: The process conditions for calcination are as follows: calcination at 120-150°C for 60 min, at 180-200°C for 60 min, at 400-420°C for 60 min, and at 550-570°C for 360 min.

5. The process for manufacturing a grinding wheel based on high abrasion resistance diamond micro powder as claimed in claim 1, wherein: The mixture is prepared from the following components by mass: 100 parts of modified diamond, 3-9 parts of hollow alumina microspheres, 1 part of sodium dodecylbenzenesulfonate, 7-12 parts of tetraethyl orthosilicate, 18-26 parts of aluminum nitrate, 40-50 parts of boric acid, 8-12 parts of sodium nitrate, and 2.0-2.5 parts of yttrium oxide.

6. The process for manufacturing a grinding wheel based on high abrasion resistance diamond micro powder as claimed in claim 1, wherein: In the step 2, the pressing is cold pressing, and the process conditions are as follows: pressure 20-25 MPa, and time 30-60 min; and then dried at a temperature of 60-80°C for 10-12 h.

7. The process for manufacturing a grinding wheel based on high abrasion resistance diamond micro powder as claimed in claim 1, wherein: In the step 2, the sintering process conditions are as follows: sintering temperature 670-750°C, and holding time 60-90 min; and then cooled in the furnace.

8. A grinding wheel based on high wear-resistant diamond micro-powder prepared by the preparation process according to any one of claims 1-7.