A metal bond diamond tool and a method of manufacturing the same

Abstract

The application discloses a metal binder diamond tool and a preparation method thereof, which is composed of the following components in parts by weight: 70-90 parts of a metal binder, 9-20 parts of diamond abrasive and 1-10 parts of nano-enhanced material, wherein the metal binder is prepared from Fe powder and Al powder, and the nano-enhanced material is one of nano-diamond, carbon nano-onion, nano-graphene and nano-carbon tube or a mixture of two or more thereof. The application uses low-cost Fe and Al elements as raw materials, mechanically alloyed in a certain proportion, and adds one kind of nano-enhanced material, so that the nano-enhanced material is uniformly dispersed in the binder as a reinforcing phase through a special rapid sintering process, thereby strengthening the strength and hardness of the binder, reducing the friction coefficient of the binder, and reducing the wear and grinding heat of the binder in the grinding process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of diamond tools, in particular to a metal bond diamond tool and a preparation method thereof. BACKGROUND

[0002] Metal bond diamond tools have been widely used in the machining of hard and brittle materials, such as ceramics, glass, concrete, stone, etc., due to their strong bonding strength, good formability, and long service life. Metal bond diamond tools are mainly composed of diamond abrasive particles and a binder. The binder can be classified into cobalt-based, copper-based, and iron-based binders. However, in order to improve the mechanical properties of the metal binder and the wetting state of the diamond, a large amount of alloying elements, including various heavy metal elements such as Ni, Co, Cu, Zn, Sn, Pb, and Cr, are often added to the metal binder. Although these alloying elements improve the performance of the metal binder, they can cause heavy metal pollution to the environment to some extent as the diamond tool wears out during the machining process. In recent years, the prices of non-ferrous metals have continued to rise, and the use of these elements will inevitably increase the preparation cost of the diamond tool. In addition, the specific gravity of the existing alloy binder is relatively high, resulting in a large weight of the diamond tool, high energy consumption, and high noise during machining.

[0003] Specifically, in order to meet the application of diamond tools in the fields of cutting, grinding of natural stone, ceramics, and concrete, as well as oil drilling, geological exploration, and mining, common metal binders generally use multi-alloying or heavy metals to enhance the mechanical properties of the binder and improve the wetting state of the diamond. Co, Ni, and Cu are the most commonly added alloying elements in metal binders. In addition, Cr and Zr are often added as strong carbide-forming elements to improve the wetting effect of the binder on the diamond. Fe-based binders are also multi-alloyed (Ni, Cu, Sn, Zn, and Mn) to improve their poor toughness and temperature sensitivity. Carbide (tungsten) based binders usually use WC, W2C, or W powder, and are doped with appropriate amounts of heavy metal components such as Cu, Sn, Zn, Co, or Ni. On the one hand, these elements may enter the ecosystem with the wear of the diamond tool, causing a certain degree of heavy metal pollution to the environment. On the other hand, the rising prices of non-ferrous metals have led to an increase in the preparation cost of the tool. In addition, the specific gravity of the existing metal binder is relatively high (8.0-10.2 g / cm 3 ), which also leads to high weight of large-size tools, high energy consumption and noise during machining, and high labor intensity of the operating personnel. SUMMARY

[0004] In view of the defects in the prior art, one of the purposes of the present application is to provide a metal binder diamond tool. The present application uses low-cost Fe and Al elements as raw materials, mechanically alloyed in a certain proportion, and adds a nano-enhanced material. During the sintering process, the nano-enhanced material acts as a reinforcing phase, uniformly dispersing in the binder, strengthening the strength and hardness of the binder, reducing the friction coefficient of the binder, and reducing the wear and grinding heat of the binder during grinding.

[0005] The second purpose of the present application is to provide a preparation method of a metal binder diamond tool. Based on the component formula design of the present application, a rapid sintering process is used to prepare the diamond tool. Through this process, the diamond tool of the formula can be rapidly densified and sintered. In this process, Fe and Al can quickly form a high-strength alloy containing intermetallic compounds, obtaining higher strength and hardness. At the same time, in this process, the nano-enhanced material can partially form a new reinforcing phase with the binder, further strengthening the binder, and also reducing the friction coefficient, reducing the thermal damage of the diamond, and reducing the sintering energy consumption.

[0006] One of the purposes of the present application is achieved by the following technical solutions:

[0007] A metal binder diamond tool is composed of the following components by weight: 70-90 parts of a metal binder, 9-20 parts of a diamond abrasive, and 1-10 parts of a nano-enhanced material. The metal binder uses Fe powder and Al powder as raw materials, and the mass ratio of Fe powder to Al powder is 7:1-1:1. The nano-enhanced material is one or a mixture of two or more of nano-diamond, carbon nano-onion, nano-graphene, and nano-carbon tube.

[0008] Further, the mass ratio between the metal binder, the diamond abrasive and the nano-enhanced material is 80:19:1-7:2:1.

[0009] Further, the particle size range of the Fe powder and the Al powder is 10-100 μm.

[0010] Further, the particle size range of the nano-enhanced material is 5-100 nm.

[0011] The second purpose of the present application is achieved by the following technical solutions:

[0012] A preparation method of a metal binder diamond tool, comprising the following steps:

[0013] 1) Preparation of nano-suspension: add nano-enhanced material to alcohol solution, then add stearic acid, and ultrasonic dispersion to prepare uniform nano-suspension;

[0014] 2) Preparation of the mechanical alloying powder: mix the Fe powder and the Al powder according to the formula amount, and perform mechanical alloying ball milling treatment on the mixed powder to obtain the mechanical alloying powder;

[0015] 3) Mixing of raw materials: mix the nanosuspension, the mechanical alloying powder and the diamond abrasive according to the formula amount, and put them into a ball mill for fully mixing, vacuum drying, and obtaining the mixed powder;

[0016] 4) Cold pressing forming: perform cold pressing forming on the mixed powder to obtain a green body;

[0017] 5) Rapid sintering treatment: heat the green body to 900-1200℃, keep the temperature for 1-120s, then cool to 500-900℃, keep the temperature for 5-40min, and then cool to room temperature with the sintering furnace, to obtain the diamond tool, the sintering pressure in the heating stage is 20-100MPa, and the protective atmosphere is argon or nitrogen.

[0018] Further, in the preparation step of the nanosuspension, the nano-reinforcing material is added into the alcohol solution according to 1-10% of the mass fraction, the stearic acid is added into the alcohol solution according to 1-10% of the mass fraction, and the ultrasonic dispersion time is 0.5-2h.

[0019] Further, in the preparation step of the mechanical alloying powder, the mechanical alloying ball milling treatment adopts a rotating speed of 150-350r / min, and the ball milling time is 3-15h.

[0020] Further, in the mixing step of the raw materials, the rotating speed of the ball mill is 100-350r / min, the ball milling time is 0.5-5h, and the ball-to-material ratio is 5:1-15:1.

[0021] Further, in the cold pressing forming step, the cold pressing pressure is 100-250MPa, and the green body density is 40-60%.

[0022] Further, in the rapid sintering treatment step, the heating rate in the heating stage is 30-50℃ / min, and the cooling rate in the cooling stage is 30-60℃ / min.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] The metal binder diamond tool of the present application uses simple and low-cost Fe powder and Al powder as the raw materials of the binder, mechanically alloys the Fe powder and the Al powder in a certain proportion, and simultaneously adds a nano-enhancing material. During the sintering process, the nano-enhancing material plays three roles: (1) the nano-particles are uniformly dispersed in the metal binder as the enhancing phase, effectively improving the strength and hardness of the diamond tool; (2) part of the nano-enhancing material reacts with Fe and Al or the compound of Fe and Al to form a new enhancing phase, further strengthening the strength and hardness of the binder; and (3) another part of the nano-enhancing material is uniformly dispersed in the binder and used to reduce the friction coefficient of the binder, which is conducive to reducing the wear and grinding heat of the binder during grinding. The present application significantly reduces the types and contents of alloying elements, reduces the risk of heavy metal pollution and the cost of materials, and also reduces the density of the binder. The obtained metal binder has excellent mechanical properties, and the prepared diamond tool has excellent processing performance.

[0025] The preparation method of the metal binder diamond tool of the present application is based on the composition formula design of the above binder, and a special rapid sintering process is used to prepare the diamond tool. The rapid reaction and densification are carried out at a high temperature, and the complete reaction is carried out at a low temperature. Through the process, the diamond tool of the formula can be rapidly densified and sintered. Fe and Al in the process can quickly form a high-strength alloy containing metal bond compounds, obtain high strength and hardness, and under the process, the nano-enhancing material can partially form a new enhancing phase with the binder, further strengthen the binder, and also reduce the friction coefficient, reduce the thermal damage of the diamond, and reduce the sintering energy consumption. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a micro-morphology comparison diagram of the binder in Comparative Example 1 and Example 1.

[0027] Figure 2 is a comparison diagram of the friction coefficients of the binder in Comparative Example 1 and Example 1 before and after grinding.

[0028] Figure 3 is a micro-morphology comparison diagram of the diamond tool in Comparative Example 1 and Example 1 before and after grinding.

[0029] Figure 4 is the micro-morphology of the binder in Example 3.

[0030] Figure 5 is a micro-morphology comparison diagram of the diamond tool in Example 3 before and after grinding.

[0031] Figure 6 is a micro-morphology comparison diagram of the Al2O3 ceramic in Example 3 before and after grinding. DETAILED DESCRIPTION

[0032] The application will be further described below in conjunction with the specific embodiments. It should be noted that the embodiments described below or the technical features between the embodiments can be combined in any manner to form new embodiments without conflict.

[0033] A metal binder diamond tool is prepared from the following components by weight: 70-90 parts of a metal binder, 9-20 parts of a diamond abrasive, and 1-10 parts of a nano-enhancing material, which are mixed in a mass ratio of 80:19:1-7:2:1. The metal binder is prepared from Fe powder and Al powder as raw materials, the mass ratio of the Fe powder to the Al powder being 7:1-1:1, the diamond abrasive is diamond grit, and the nano-enhancing material is at least one of nano-diamond, carbon nano-onion, nano-graphene, and nano-carbon tube. As a preferred embodiment, the nano-enhancing material is selected from one of nano-diamond, carbon nano-onion, nano-graphene, and nano-carbon tube.

[0034] It should be noted that the nano-enhancing material should be selected from a nano-material with high hardness and high elastic modulus, for example, the tensile strength of nano-graphene is 130 GPa, and the elastic modulus is 0.5-1 TPa; the Young's modulus of nano-carbon tube is 1000 GPa, and the elastic modulus is 1 TPa.

[0035] Specifically, the particle size range of the Fe powder is 10-100 μm, the particle size range of the Al powder is 10-100 μm, and the particle size range of the nano-enhancing material is 5-100 nm.

[0036] The preparation method of the metal binder diamond tool includes the following steps:

[0037] 1) Preparation of a nano-suspension: a nano-enhancing material powder with a particle size range of 5-100 nm is selected, the nano-enhancing material being at least one of nano-diamond, carbon nano-onion, nano-graphene, and nano-carbon tube, the nano-enhancing material is added to an alcohol solution, stearic acid is further added, and ultrasonic dispersion is performed for 0.5-2 h to prepare a uniformly dispersed nano-suspension; as a preferred embodiment, the nano-enhancing material is added to the alcohol solution in a mass fraction of 1-10%, and the stearic acid is added to the alcohol solution in a mass fraction of 1-10%;

[0038] 2) Preparation of a mechanically alloyed powder: Fe powder with a particle size range of 10-100 μm and Al powder with a particle size range of 10-100 μm are mixed in a mass ratio of 7:1-1:1, and the mixed powder is subjected to mechanical alloying ball milling treatment to obtain a mechanically alloyed powder, wherein the mechanical alloying ball milling is performed at a rotation speed of 150-350 r / min, and the ball milling time is 3-15 h.

[0039] 3) Raw material mixing: the above prepared nanosuspension, mechanical alloying powder and diamond abrasive are preliminarily mixed according to a mass ratio of 80:19:1-7:2:1, and then put into a ball mill for sufficient mixing, wherein the rotation speed of the ball mill is 100-350 r / min, the ball milling time is 0.5-5 h, the ball-to-material ratio is 5:1-15:1, and the volume of the material in the ball mill tank is ensured to be less than two-thirds of the volume of the ball mill tank; the ball-milled material is vacuum dried at 70°C for 0.5-2 h to obtain uniformly mixed powder;

[0040] 4) Cold pressing forming: the above uniformly mixed powder is put into a cold pressing mold for cold pressing forming, and the cold pressing pressure is 100-250 MPa to obtain a green body, and the green body has a green body density of 40-60%;

[0041] 5) Rapid sintering treatment: the above obtained green body is sintered according to a specially designed process, the green body is placed in a sintering furnace, first heated to 900-1200°C at a heating rate of 30-50°C / min, and then cooled to 500-900°C at a cooling rate of 30-60°C / min, and then kept at 500-900°C for 5-40 min, and the sintering pressure in the heating stage is 20-100 MPa, and the protective atmosphere is argon or nitrogen, and then the sintering furnace is cooled to room temperature to obtain a diamond tool.

[0042] In combination with the above, the rapid sintering treatment step includes three stages, which are in turn a heating stage, a cooling stage and a natural cooling stage. Specifically, the temperature of the green body in the heating stage can reach 900-1200°C, at which high temperature, the material in the green body rapidly reacts to densify, and at this time, the holding time is short; in the cooling stage, the temperature in the sintering furnace is 500-900°C, and the holding time is long, at which time the material reacts completely at a lower temperature; the present application controls the sintering reaction of the green body by adjusting the sintering temperature and holding time, at 900-1200°C, Fe and Al in the green body can quickly form a high-strength alloy containing metallic bond, thereby obtaining higher strength and hardness, at the same time, at this temperature, the nano-enhanced material can react with the binder to form a new reinforcing phase, but due to the short holding time at this temperature, the nano-enhanced material will not all react with the binder, and a part of the unreacted nano-enhanced material will be dispersed in the binder, these uniformly dispersed unreacted nano-enhanced materials in the binder can reduce the friction coefficient of the binder, which is beneficial to reducing the wear and grinding heat of the binder in the grinding process.

[0043] The present application uses nano-reinforced materials instead of traditional heavy metal alloy elements to improve the mechanical properties of the binder and the wetting state of the diamond, specifically uses low-cost raw materials, namely Fe powder and Al powder, to prepare an environmentally friendly, simple composition and lightweight metal binder diamond tool by mixing in a certain proportion and using an optimized rapid sintering process.

[0044] The present application uses Fe and Al as the basis and adopts nano-reinforced methods to propose a metal binder diamond tool without using multi-alloying and heavy metal elements, which greatly reduces the heavy metal pollution caused by the diamond tool during preparation and use, and also reduces the harm to the health of production and operating personnel. Secondly, the present application also reduces the material cost of preparing the diamond tool and the weight of the diamond tool, reduces the labor intensity of the operating personnel, and reduces the power consumption and noise of the equipment. In addition, for the composition of the binder, a special rapid sintering process is used, which can not only reduce the sintering temperature and reduce the thermal damage to the diamond, but also maintain the high holding force of the binder to the diamond, reduce the energy consumption and preparation cost.

[0045] Embodiment 1

[0046] A preparation method of a metal binder diamond tool, comprising the following steps:

[0047] 1) Preparation of nano-suspension: nano-diamond is selected as the nano-reinforced material, and the particle size range is 50 nm; the nano-reinforced material is added to an alcohol solution, a stearic acid dispersant is further added, and ultrasonic dispersion is performed for 0.5 h to prepare a uniformly dispersed nano-suspension, wherein the nano-reinforced material is added to the alcohol solution in a mass fraction of 1%;

[0048] 2) Preparation of mechanical alloying powder: Fe powder with a particle size of 40 μm and Al powder with a particle size of 40 μm are preliminarily mixed in a mass ratio of 4:3, and the mixed powder is subjected to mechanical alloying ball milling treatment to obtain a mechanical alloying powder, wherein the mechanical alloying ball milling adopts a rotation speed of 250 r / min, and the ball milling time is 6 h;

[0049] 3) Mixing of raw materials: 85 parts of the above mechanical alloying powder, 13 parts of diamond abrasive and 2 parts of the above nano-suspension are preliminarily mixed, the particle size of the diamond abrasive is 50-60 mesh, and then the mixture is put into a ball mill for thorough mixing, wherein the rotation speed of the ball mill is 100 r / min, the ball milling time is 1.5 h, the ball-to-powder ratio is 10:1, and the volume of the material in the ball milling tank is ensured to be less than two-thirds of the volume of the ball milling tank; the ball-milled material is vacuum dried at 70℃ for 0.5 h to obtain uniformly mixed powder;

[0050] 4) Cold pressing: the above mixed uniform powder is put into a cold pressing mold for cold pressing, the cold pressing pressure is 150 MPa, and a green body with a green density of 45% is obtained;

[0051] 5) Rapid sintering treatment: the above obtained green body is sintered according to a specially designed process, the green body is placed in a sintering furnace, first heated to 1150°C at a heating rate of 50°C / min, kept for 10 seconds, then cooled to 750°C at a cooling rate of 30°C / min, kept for 15 min, the sintering pressure in the heating stage is 50 MPa, the protective atmosphere is nitrogen, then the sintering furnace is cooled to room temperature, and a diamond tool is obtained.

[0052] Comparative Example 1

[0053] A preparation method of a metal bond diamond tool, comprising the following steps:

[0054] 1) Preparation of mechanical alloying powder: Fe powder with a particle size of 40 μm and Al powder with a particle size of 40 μm are preliminarily mixed according to a mass ratio of 4:3, and the mixed powder is subjected to mechanical alloying ball milling treatment to obtain a mechanical alloying powder, wherein the mechanical alloying ball milling adopts a rotating speed of 250 r / min, and the ball milling time is 6 h;

[0055] 2) Mixing of raw materials: 85 parts of the above mechanical alloying powder and 13 parts of diamond abrasive are preliminarily mixed, the particle size of the diamond abrasive is 50-60 mesh, and then the mixture is put into a ball mill for sufficient mixing, wherein the rotating speed of the ball mill is 100 r / min, the ball milling time is 1.5 h, the ball-to-powder ratio is 10:1, and the volume of the material in the ball milling tank is ensured to be less than two-thirds of the volume of the ball milling tank; the ball-milled material is vacuum dried at 70°C for 0.5 h to obtain a uniformly mixed powder;

[0056] 3) Cold pressing: the above mixed uniform powder is put into a cold pressing mold for cold pressing, the cold pressing pressure is 150 MPa, and a green body with a green density of 45% is obtained;

[0057] 4) Rapid sintering treatment: the above obtained green body is sintered according to a specially designed process, the green body is placed in a sintering furnace, first heated to 1150°C at a heating rate of 50°C / min, kept for 10 seconds, then cooled to 750°C at a cooling rate of 30°C / min, kept for 15 min, the sintering pressure in the heating stage is 50 MPa, the protective atmosphere is nitrogen, then the sintering furnace is cooled to room temperature, and a diamond tool is obtained.

[0058] Comparative Example 1 and Example 1 only differ in the raw materials used, i.e. no nano-enhancing material is added in Comparative Example 1.

[0059] Effect evaluation and performance detection:

[0060] As Figure 1 shown, after using the rapid sintering process, it can be seen that the nano-reinforced material (referred to as nano material in the figure) refines the grain size of the binder, and at the same time, the nano-reinforced material reacts with the binder to form a new reinforcing phase, which greatly improves the mechanical properties of the metal binder. After testing, the hardness and bending strength of Comparative Example 1 are 95 HRB and 700 MPa respectively, and after adding the nano-reinforced material, the hardness of Example 1 is increased to 106.5 HRB, and the bending strength is increased to 800 MPa. At the same time, the density of Example 1 is measured to be 5.3 g / cm 3 .

[0061] As Figure 2 shown, compared with Comparative Example 1, the friction coefficient of Example 1 with nano-reinforced material is significantly reduced, and the diamond tool prepared by using Example 1 can be used to grind Al2O3 ceramic, and the grinding ratio can be increased from 400 to 650.

[0062] As Figure 3 shown, before grinding, compared with Comparative Example 1, the diamond in Example 1 is better embedded in the binder, and after grinding, only the diamond in Example 1 is broken, and no diamond is found to fall off, which indicates that the binder in Example 1 has better holding force on the diamond. At the same time, for Example 1, the Al2O3 ceramic after being ground is mainly in a typical brittle removal mechanism, and has a high surface quality after grinding, with a surface roughness (Ra) of only 0.12 μm.

[0063] The binder prepared in Example 1 has good affinity and wettability to diamond, which not only reduces the use of alloying elements, but also avoids heavy metal pollution and harm to the health of production and operating personnel, and also reduces the material cost and tool weight of the diamond tool; the nano-reinforced material strengthens the binder, and the reinforcing phase formed by the reaction of the nano-reinforced material and the binder strengthens the binder together, which improves the strength, hardness and wear resistance of the binder; through the special rapid sintering process, not only the sintering temperature and energy consumption of the diamond tool are reduced, but also the mechanical properties of the binder and the holding force on the diamond are maintained, and the thermal damage to the diamond is reduced.

[0064] In summary, after adding the nano-reinforced material, the obtained binder has more excellent mechanical properties, and the prepared diamond tool also has excellent machining performance.

[0065] Example 2

[0066] A preparation method of a metal binder diamond tool, comprising the following steps:

[0067] 1) Preparation of the nano-suspension: nano-graphene is selected as the nano-reinforcing material, the particle size of which is 50 nm. The nano-reinforcing material is added into an alcohol solution, and then stearic acid dispersant is added. The mixture is ultrasonically dispersed for 1 h to prepare a uniformly dispersed nano-suspension. In the process, the nano-reinforcing material is added into the alcohol solution in a mass fraction of 3%;

[0068] 2) Preparation of the mechanically alloyed powder: Fe powder with a particle size of 35 μm and Al powder with a particle size of 35 μm are preliminarily mixed in a mass ratio of 5:3. The mixed powder is subjected to mechanical alloying ball milling treatment to prepare a mechanically alloyed powder. In the process, the mechanical alloying ball milling is performed at a rotation speed of 300 r / min for 5 h;

[0069] 3) Mixing of the raw materials: 88 parts of the mechanically alloyed powder, 11 parts of diamond abrasive material, and 1 part of the nano-suspension are preliminarily mixed. The diamond abrasive material has a particle size of 50-60 mesh. The mixture is then put into a ball mill and mixed thoroughly. In the process, the ball mill is rotated at a speed of 150 r / min for 0.5 h. The volume of the material in the ball mill is ensured to be less than two-thirds of the volume of the ball mill. The milled material is vacuum dried at 70℃ for 1 h to obtain a uniformly mixed powder;

[0070] 4) Cold pressing: the uniformly mixed powder is put into a cold pressing mold and cold pressed at a pressure of 200 MPa to obtain a green body with a green density of 50%;

[0071] 5) Rapid sintering: the green body is sintered according to a specially designed process. The green body is placed in a sintering furnace, heated to 1100℃ at a heating rate of 45℃ / min, and then cooled to 800℃ at a cooling rate of 45℃ / min. The sintering pressure in the heating stage is 50 MPa, and the protective atmosphere is nitrogen. The sintering furnace is then cooled to room temperature to obtain a diamond tool.

[0072] Comparative Example 2

[0073] A method for preparing a metal bond diamond tool, comprising the following steps:

[0074] 1) Preparation of the mechanically alloyed powder: Fe powder with a particle size of 35 μm and Al powder with a particle size of 35 μm are preliminarily mixed in a mass ratio of 5:3. The mixed powder is subjected to mechanical alloying ball milling treatment to prepare a mechanically alloyed powder. In the process, the mechanical alloying ball milling is performed at a rotation speed of 300 r / min for 5 h;

[0075] 2) Raw material mixing: 88 parts of the mechanical alloying powder and 11 parts of diamond abrasive are preliminarily mixed, the particle size of the diamond abrasive is 50-60 mesh, and then the mixture is put into a ball mill, the rotation speed of the ball mill is 150 r / min, the ball milling time is 0.5 h, and the volume of the material in the ball mill is ensured to be less than two-thirds of the volume of the ball mill; the ball-milled material is vacuum dried at 70°C for 1 h to obtain uniformly mixed powder;

[0076] 4) Cold pressing: the uniformly mixed powder is put into a cold pressing mold for cold pressing, the cold pressing pressure is 200 MPa, and a green body with a density of 50% is obtained;

[0077] 5) Rapid sintering treatment: the green body obtained above is sintered according to a specially designed process, the green body is placed in a sintering furnace, first heated to 1100°C at a heating rate of 45°C / min, kept for 1 s, then cooled to 800°C at a cooling rate of 45°C / min, kept for 12 min, the sintering pressure in the heating stage is 50 MPa, the protective atmosphere is nitrogen, and then the sintering furnace is cooled to room temperature, and a diamond tool is obtained.

[0078] Comparative Example 2 and Example 2 only differ in the raw materials used, i.e. no nano-enhancing material is added in Comparative Example 2.

[0079] Effect evaluation and performance detection:

[0080] After using the rapid sintering process, the nano-enhancing material refines the grain size of the metal binder, and the nano material reacts with the binder to form a new reinforcing phase, greatly improving the mechanical properties of the metal binder. According to the test, the hardness and bending strength of Comparative Example 2 are 92 HRB and 600 MPa respectively, after adding the nano-enhancing material, the hardness of Example 2 is increased to 104 HRB, and the bending strength is increased to 850 MPa, at the same time, the density of Example 2 is only 5.6 g / cm 3 .

[0081] Compared with Comparative Example 2, the friction coefficient of Example 2 with nano-reinforced material is significantly reduced, and the diamond tool prepared by using Example 2 is used to grind Al2O3 ceramic, and the grinding ratio can be increased from 380.5 to 661. Before grinding, the diamond in Example 2 is better embedded in the binder, and after grinding, the diamond in Comparative Example 2 falls off a little, while the diamond in Example 2 only breaks and no falling off is found, and the binder in Example 2 has better holding force on the diamond. At the same time, for Example 2, the ground Al2O3 ceramic is mainly in typical brittle removal mechanism, and has high surface quality after grinding, with surface roughness (Ra) of only 0.12 μm. In summary, after adding nano-reinforced material, the binder obtained has more excellent mechanical properties, and the diamond tool prepared also has excellent processing performance.

[0082] Example 3

[0083] A preparation method of a metal binder diamond tool, comprising the following steps:

[0084] 1) Preparation of mechanically alloyed powder: Fe powder with a particle size of 75 μm and Al powder with a particle size of 75 μm are preliminarily mixed in a mass ratio of 6:1, and the mixed powder is subjected to mechanical alloying ball milling treatment to obtain a mechanically alloyed powder, wherein the mechanical alloying ball milling adopts a rotation speed of 250 r / min, and the ball milling time is 6 h;

[0085] 2) Mixing of raw materials: 88 parts of the above mechanically alloyed powder and 12 parts of diamond abrasive are preliminarily mixed, the particle size of the diamond abrasive is 50-60 mesh, and then put into a ball mill for sufficient mixing, wherein the rotation speed of the ball mill is 150 r / min, the ball milling time is 1 h, and the volume of the material in the ball milling tank is ensured to be not more than two-thirds of the volume of the ball milling tank; the ball-milled material is vacuum dried at 70℃ for 1 h to obtain a uniformly mixed powder;

[0086] 3) Cold pressing: the uniformly mixed powder is placed into a cold pressing mold for cold pressing, and the cold pressing pressure is 200 MPa to obtain a green body with a green body density of 50%;

[0087] 4) Rapid sintering treatment: the green body obtained above is sintered according to a specially designed process, the green body is placed in a sintering furnace, first heated to 1150℃ at a heating rate of 40℃ / min, kept for 1 second, then cooled to 850℃ at a cooling rate of 45℃ / min, kept for 10 min, and then cooled to room temperature with the sintering furnace to obtain a diamond tool.

[0088] As Figure 4As shown, after using a special rapid sintering process, no obvious pores or cracks were formed in the binder, resulting in a high degree of densification. Simultaneously, the hardness and flexural strength reached 108.4 HRB and 1104 MPa, respectively, which are superior to the mechanical properties of existing binders made solely from Fe and Al powders. The measured density was only 6.4 g / cm³. 3 Using diamond tools to grind Al2O3 ceramics, a grinding ratio of 70:2 can be achieved. Figure 5 As shown, before grinding, the diamond was well-bonded by the binder. After grinding, the diamond only fractured and did not fall off, indicating that the binder has good holding power for the diamond. Meanwhile, as... Figure 6 As shown, the ground Al2O3 ceramic exhibits a typical brittle removal mechanism, resulting in high surface quality with a surface roughness (Ra) of only 0.12 μm. In conclusion, even without the addition of nano-reinforcing materials, the binder obtained through rapid sintering processes possesses excellent mechanical properties, and the prepared diamond tools exhibit excellent machinability.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should fall within the protection scope of the present invention.

Claims

1. A metal bond diamond tool, characterized by, consists of components by weight parts: 70 90 parts of metal binder, 9 20 parts of diamond abrasive and 1 10 parts of nano-reinforced material, the metal binder is made of Fe powder and Al powder, the mass ratio of Fe powder and Al powder is 7:1 1:1, the nano-reinforced material is one or a mixture of two or more of nano-diamond, carbon nano-onion, nano-graphene and nano-carbon tube; The metal binder diamond tool is prepared by a preparation method comprising the following steps: 1) preparation of a nano-suspension: nano-enhancing materials are added to an alcohol solution, stearic acid is added, and ultrasonic dispersion is performed to prepare a uniformly dispersed nano-suspension; 2) preparation of a mechanically alloyed powder: Fe powder and Al powder are mixed according to a formula amount, and the mixed powder is subjected to mechanical alloying ball milling treatment to obtain a mechanically alloyed powder; 3) mixing of raw materials: the nano-suspension, the mechanically alloyed powder, and diamond abrasives are mixed according to a formula amount, and are fully mixed and uniformly distributed in a ball mill, and are vacuum dried to obtain uniformly mixed powder; 4) cold pressing: the uniformly mixed powder is cold pressed to obtain a green body; 5) fast sintering process: heating the green body to 900 1200°C, holding for 1 20s, and then cooling to 500 900°C, holding for 5 40min, and then cooling to room temperature with the sintering furnace, to obtain a diamond tool, the sintering pressure in the heating stage being 20 100MPa, and the protective atmosphere being argon or nitrogen.

2. A metal bond diamond tool according to claim 1, wherein The mass ratio between the metal binding agent, the diamond abrasive and the nano-reinforcement material is 80:19:1 7:2:

1.

3. A metal bond diamond tool according to claim 1, wherein The particle size range of the Fe powder and the Al powder is each 10 100 μm.

4. A metal bond diamond tool according to claim 1, wherein The nano-reinforcing material has a particle size range of 5 100 nm.

5. A method of producing the metal bond diamond tool according to any one of claims 1 to 4, characterized by, comprising the following steps: 1) preparation of a nano-suspension: nano-enhancing materials are added to an alcohol solution, stearic acid is added, and ultrasonic dispersion is performed to prepare a uniformly dispersed nano-suspension; 2) preparation of a mechanically alloyed powder: Fe powder and Al powder are mixed according to a formula amount, and the mixed powder is subjected to mechanical alloying ball milling treatment to obtain a mechanically alloyed powder; 3) mixing of raw materials: the nano-suspension, the mechanically alloyed powder, and diamond abrasives are mixed according to a formula amount, and are fully mixed and uniformly distributed in a ball mill, and are vacuum dried to obtain uniformly mixed powder; 4) cold pressing: the uniformly mixed powder is cold pressed to obtain a green body; 5) fast sintering process: heating the green body to 900 1200°C, holding for 1 20s, and then cooling to 500 900°C, holding for 5 40min, and then cooling to room temperature with the sintering furnace, to obtain a diamond tool, the sintering pressure in the heating stage being 20 100MPa, and the protective atmosphere being argon or nitrogen.

6. A method of making a metal-bonded diamond tool according to claim 5, wherein, In the preparation step of the nanosuspension, the nanoreinforcement material is added in an alcoholic solution at a mass fraction of 1 10% in an alcoholic solution, stearic acid is added in an alcoholic solution at a mass fraction of 1 10% in an alcoholic solution, the ultrasonic dispersion time is 0.5 2 h.

7. A method of making a metal-bonded diamond tool according to claim 5, wherein, In the step of preparing the mechanical alloying powder, the mechanical alloying ball milling treatment was carried out at a rotation speed of 150 350 r / min, and the ball milling time was 3 15 h.

8. A method of making a metal-bonded diamond tool according to claim 5, wherein, The rotational speed of the ball mill was 100 350 r / min, the ball milling time was 0.5 5 h, and the ball-to-material ratio was 5:1 15:

1.

9. A method of making a metal-bonded diamond tool according to claim 5, wherein, In the cold press forming step, the cold press pressure is 100 250 MPa, and the compact density of the compact is 40 60 %.

10. A method of making a metal-bonded diamond tool according to claim 5, wherein, In the step of rapid sintering treatment, the temperature rising stage adopts 30 50℃ / min of temperature rising rate, and the cooling stage adopts 30 60℃ / min of cooling rate.

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