阅读说明：本技术 一种高速磨削砂轮用基体及其制备方法、超硬磨料砂轮 (Matrix for high-speed grinding wheel, preparation method of matrix and superhard abrasive grinding wheel ) 是由 李德启 李�东 苏永壁 刘永军 于 2020-05-26 设计创作，主要内容包括：本发明属于磨削磨具技术领域,具体涉及一种高速磨削砂轮用基体及其制备方法,还涉及一种超硬磨料砂轮。本发明的高速磨削砂轮用基体由以下质量百分比的原料制成：二元合金20～55％,单质金属5～15％,无机晶须5～40％,散热材料5～15％,玻璃纤维5～15％,石墨10～20％,粘接剂5～10％,润湿剂1～5％；所述二元合金为铁铜合金和/或镍钛合金；所述单质金属为锡、铜、银中的一种或多种；所述散热材料为氧化锌、二硫化钼、冰晶石中的至少一种。本发明的砂轮基体具有硬度高,刚性好,热膨胀系数小等优点,采用本发明的砂轮基体的砂轮在磨削速度大于120m/s时仍能保证基体不变形、不发生断裂,满足高速磨削的使用要求。(The invention belongs to the technical field of grinding tools, and particularly relates to a matrix for a high-speed grinding wheel and a preparation method thereof, and further relates to a superhard abrasive grinding wheel. The matrix for the high-speed grinding wheel is prepared from the following raw materials in percentage by mass: 20-55% of binary alloy, 5-15% of simple substance metal, 5-40% of inorganic whisker, 5-15% of heat dissipation material, 5-15% of glass fiber, 10-20% of graphite, 5-10% of adhesive and 1-5% of wetting agent; the binary alloy is an iron-copper alloy and/or a nickel-titanium alloy; the elementary metal is one or more of tin, copper and silver; the heat dissipation material is at least one of zinc oxide, molybdenum disulfide and cryolite. The grinding wheel base body has the advantages of high hardness, good rigidity, small thermal expansion coefficient and the like, and the grinding wheel adopting the grinding wheel base body can still ensure that the base body is not deformed and broken when the grinding speed is more than 120m/s, thereby meeting the use requirement of high-speed grinding.)

1. The matrix for the high-speed grinding wheel is characterized by being prepared from the following raw materials in percentage by mass: 20-55% of binary alloy, 5-15% of simple substance metal, 5-40% of inorganic whisker, 5-15% of heat dissipation material, 5-15% of glass fiber, 10-20% of graphite, 5-10% of adhesive and 1-5% of wetting agent; the binary alloy is an iron-copper alloy and/or a nickel-titanium alloy; the elementary metal is one or more of tin, copper and silver; the heat dissipation material is at least one of zinc oxide, molybdenum disulfide and cryolite.

2. The base for a high-speed grinding wheel according to claim 1, wherein the mass ratio of iron to copper in the iron-copper alloy is 85:15 or 70: 30, the mass ratio of nickel to titanium in the nickel-titanium alloy is 65: 35.

3. the substrate for a high-speed grinding wheel according to claim 1 or 2, wherein the binary alloy is an iron-copper alloy, and the elemental metal is copper or tin; or the binary alloy is nickel-titanium alloy, and the elementary metal is copper.

4. The base for a high-speed grinding wheel according to claim 1 or 2, wherein the particle size of the binary alloy is 200 to 1000 mesh, the particle size of the elemental metal is 200 to 1000 mesh, the particle size of the zinc oxide is 2000 to 10000 mesh, and the particle size of the graphite is 100 to 1500 mesh.

5. The substrate for a high-speed grinding wheel according to claim 1 or 2, wherein the inorganic whiskers are one or more of barium sulfate whiskers, calcium sulfate whiskers, and silicon carbide whiskers.

6. The substrate for a high-speed grinding wheel according to claim 5, wherein the inorganic whiskers have a diameter of 10 to 50 μm and an aspect ratio of 5 to 25.

7. The substrate for a high-speed grinding wheel according to claim 1 or 2, wherein the glass fiber has a diameter of 50 to 150 μm and an aspect ratio of 10 to 20.

8. A method for producing a substrate for a high-speed grinding wheel according to any one of claims 1 to 7, comprising the steps of: mixing the raw materials according to the mass percentage, and drying to obtain a mixture; and carrying out hot-pressing sintering on the mixture, and then cooling.

9. The method for producing a substrate for a high-speed grinding wheel according to claim 8, wherein the drying temperature is 50 to 100 ℃ and the drying time is 10 to 90 minutes.

10. The method for manufacturing a base body for a high-speed grinding wheel according to claim 8, wherein the pressure of the hot-press sintering is 2 to 20MPa, the temperature is 550 to 600 ℃, and the time is 5 to 80 min.

11. The method for manufacturing the base body for the high-speed grinding wheel according to any one of claims 8 to 10, wherein the temperature reduction is specifically: and cooling by adopting a ventilation and blowing mode, wherein the ventilation and cooling is carried out pneumatically, the air temperature is 40-60 ℃, the air flow temperature is 5-10 m/s, and the time is 10-25 min.

12. A superabrasive grinding wheel using the substrate for high-speed grinding as set forth in any one of claims 1 to 7.

Technical Field

The invention belongs to the technical field of grinding tools, and particularly relates to a matrix for a high-speed grinding wheel and a preparation method thereof, and further relates to a superhard abrasive grinding wheel.

Background

High-speed grinding (the grinding speed is more than 80m/s) is an efficient and high-performance processing method, and compared with ordinary grinding, the high-speed grinding has the advantages of being good in grinding efficiency, processing precision and grinding wheel abrasion. At present, a common high-speed grinding tool is a superhard abrasive grinding wheel, the superhard abrasive grinding wheel fully exerts the advantages of high hardness and high sharpness of superhard abrasives (diamond and cubic boron nitride) in a high-speed grinding process, and the workpiece to be processed is precisely and efficiently processed.

Superabrasive wheels are generally composed of two major parts, an abrasive layer and a matrix supporting the abrasive layer. The abrasive layer is generally composed of super-hard abrasive, binder (adhesive and functional filler), and air holes. In the high-speed grinding process, a base matched with the abrasive layer is necessary to fully exert the high-speed sharp grinding of the abrasive layer.

The existing common superhard abrasive grinding wheel base body is generally a steel base body, an aluminum base body, a bakelite base body, a carbon fiber base body and the like. In the high-speed grinding process, the steel matrix, the aluminum matrix and the bakelite matrix are deformed to different degrees and are easy to separate from the grinding material layer; although the carbon fiber matrix is not easy to deform, because high-speed grinding can produce a large amount of heat, repeated use can cause fatigue, finally cause damage, fracture easily for the dynamic balance precision of emery wheel is out of tolerance, easily produces the shake line when causing the emery wheel grinding work piece, and causes the strain of lathe main shaft.

Therefore, the existing base body is easy to deform, separate from the abrasive layer, break and the like in the high-speed grinding process, so that the use requirement of high-speed grinding cannot be met.

Disclosure of Invention

The invention aims to provide a base body for a high-speed grinding wheel, which is not easy to deform and has good dynamic balance in the high-speed grinding process and can be applied to a grinding wheel with the grinding speed of more than 120 m/s.

The invention also aims to provide a preparation method of the matrix for the high-speed grinding wheel.

The invention also aims to provide a superhard abrasive grinding wheel adopting the matrix for the high-speed grinding wheel.

In order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows:

a matrix for a high-speed grinding wheel is prepared from the following raw materials in percentage by mass: 20-55% of binary alloy, 5-15% of simple substance metal, 5-40% of inorganic whisker, 5-15% of heat dissipation material, 5-15% of glass fiber, 10-20% of graphite, 5-10% of adhesive and 1-5% of wetting agent; the binary alloy is an iron-copper alloy and/or a nickel-titanium alloy; the elementary metal is one or more of tin, copper and silver; the heat dissipation material is at least one of zinc oxide, molybdenum disulfide and cryolite; the adhesive is at least one of paraffin, phenolic resin and water glass.

According to the matrix for the high-speed grinding wheel, the used binary alloy is a main metal phase structure material, two metal elements in the binary alloy can generate metal phase change in the preparation process of the matrix, and other raw materials are firmly held together to form a matrix skeleton structure with proper strength and hardness. Thus, binary alloys are among the primary binders and base structures that support the matrix for high speed grinding wheels of the present invention. The single metal further increases the toughness of the binary alloy phase-changed integral matrix, reduces the brittleness of the integral matrix and prevents brittle fracture during high-speed rotation; the elemental metal also increases the density of the overall matrix, thereby increasing the strength and hardness of the overall matrix.

The inorganic whisker and the glass fiber have two functions: firstly, a network skeleton structure is formed in an organization structure together with binary alloy, so that the overall material has good strength and toughness, and the impact toughness and the fracture strength are increased; secondly, the crystal whisker has certain heat conduction and radiation effects, and the heat transfer and dispersion effects of the matrix are good when the grinding machine is used for high-load grinding, so that the reduction of local mechanical strength caused by heat concentration is avoided.

The heat dissipation material has good heat conduction performance, and is also uniformly dispersed in a metal phase as inorganic non-metal particles, so that the brittleness of a metal matrix can be reduced, and the impact toughness can be improved.

The graphite is used for increasing the heat conductivity of the binary alloy when the raw materials react, and is used as an intermediate medium to uniformly disperse heat and promote the reaction to be uniformly carried out.

The adhesive is a temporary adhesive, and the raw materials are uniformly dispersed and mixed in the preparation process. Preferably, the adhesive is at least one of paraffin, phenolic resin and water glass. The wetting agent is used for fully wetting the surfaces of the raw materials, and the raw materials are uniformly combined. Preferably, the wetting agent has viscosity at a lower temperature (namely, a low-temperature active wetting agent), loses viscosity at a temperature of 40 ℃, is a temporary wetting agent, can fully wet the surfaces of binary alloy and simple substance metal particles, is more favorable for bonding of an adhesive, enables the mixing uniformity of all raw materials to be realized, and ensures the tissue uniformity of the grinding wheel matrix. The low-temperature active wetting agent is selected to play a temporary wetting role, reduce the surface activity of various raw materials and facilitate the uniformity of mixed materials, and the wetting agent loses activity along with the rise of reaction temperature so as to ensure that the rest raw materials fully react. Further preferably, the wetting agent used in the present invention is one or more of mixed cresol, vulcanized oil and glycerin.

In the matrix for the high-speed grinding wheel, all main raw materials are coordinated with each other, so that a good metallographic structure is formed. The grinding wheel matrix has the advantages of high hardness, good rigidity, small thermal expansion coefficient, uniform structure and good dynamic balance performance, and the mechanical properties of the grinding wheel matrix are far superior to those of common metal matrixes (aluminum, copper, steel and the like) and carbon fiber matrixes in all aspects. The grinding wheel base body is suitable for the superhard abrasive grinding wheels adopting different bonding agents (ceramic, resin and metal bonding agents), and the grinding wheel adopting the grinding wheel base body can still ensure that the base body is not deformed and broken when the grinding speed is more than 120m/s, so that the use requirement of high-speed grinding is met.

Preferably, the matrix for the high-speed grinding wheel is prepared from the following raw materials in percentage by mass: 20-25% of binary alloy, 10-15% of simple substance metal, 30-35% of inorganic whisker, 5-10% of heat dissipation material, 5% of glass fiber, 10% of graphite, 6-7% of adhesive and 3-4% of wetting agent.

The mass ratio of iron to copper in the iron-copper alloy is 85:15 or 70: 30, the mass ratio of nickel to titanium in the nickel-titanium alloy is 65: 35.

Further preferably, the binary alloy is an iron-copper alloy, and the elemental metal is copper or tin; or the binary alloy is nickel-titanium alloy, and the elementary metal is copper. The binary alloy and the simple substance metal combination are adopted, so that the structural uniformity of a metal phase is improved, and the strength, toughness and hardness of the whole matrix are improved.

In the matrix for the high-speed grinding wheel, the binary alloy, the simple substance metal and the heat dissipation material are all powder materials in order to ensure the mixing uniformity of all raw materials.

The smaller the binary alloy particles are, the better the hardness and strength of the matrix for the high-speed grinding wheel can be improved, and the particle size of the preferred binary alloy is 200-1000 meshes. Further preferably, the particle size of the binary alloy is 200-500 meshes. In order to improve the mixing uniformity of the powder raw materials, the particle size of the used simple substance metal is preferably 200-1000 meshes, and the particle size of the used simple substance metal is further preferably 200-500 meshes. Preferably, the particle size of the heat dissipation material is 2000-10000 meshes, and further preferably, the particle size of the heat dissipation material is 2000-5000 meshes. Preferably, the particle size of the graphite is 100-1500 meshes. Further preferably, the graphite used has a particle size of 100 mesh, 500 mesh, 1200 mesh or 1500 mesh. More preferably, the graphite used is flake graphite.

In the matrix for a high-speed grinding wheel according to the present invention, the inorganic whiskers used are preferably ceramic whiskers and/or inorganic salt whiskers. Preferably, the inorganic salt whisker is one or more of barium sulfate whisker and calcium sulfate whisker. Preferably, the ceramic whiskers are silicon carbide whiskers.

The matching degree of the inorganic whisker and the glass fiber with other raw materials is improved by adjusting the size of the inorganic whisker and the glass fiber, the diameter of the preferable inorganic whisker is 10-50 mu m, and the length-diameter ratio is 5-25; further preferably, the inorganic whiskers have a diameter of 10 to 35 μm. Preferably, the diameter of the glass fiber is 50-150 μm, and the length-diameter ratio is 10-20; further preferably, the diameter of the glass fiber is 100 to 150 μm.

The preparation method of the matrix for the high-speed grinding wheel adopts the technical scheme that:

the preparation method of the matrix for the high-speed grinding wheel comprises the following steps: mixing the raw materials according to the mass percentage, and drying to obtain a mixture; and carrying out hot-pressing sintering on the mixture, and then cooling.

The preparation method of the matrix for the high-speed grinding wheel is simple and is beneficial to large-scale production.

In the preparation method of the matrix for the high-speed grinding wheel, the mixing method for mixing the raw materials can be adjusted according to the actual situation, and the raw materials are only required to be uniformly mixed. Preferably, the mixing is carried out by adopting a ball milling method, and the mixing time is 10-60 min.

After mixing, the adhesive and the wetting agent are removed in the drying process, so that the adhesive and the wetting agent can be prevented from generating micromolecular gas at high temperature in the subsequent sintering process to escape, and the matrix can be prevented from generating air holes or internal cavities. And the rest raw materials are kept in a dry state, which is beneficial to the implementation of the subsequent steps. Preferably, the drying temperature is 150-200 ℃ and the drying time is 10-90 min.

In the hot pressing sintering process, the base body is finally molded. Preferably, the pressure of the hot-pressing sintering is 2-20 MPa, the temperature is 550-600 ℃, and the time is 5-80 min.

The cooling is carried out in a ventilation and blowing mode, the ventilation and cooling are carried out pneumatically, the temperature of air is 40-60 ℃, the temperature of air flow is 5-10 m/s, and the time is 10-25 min. The base body is cooled all around by controlling the ventilation condition during cooling, so that the base body is slowly cooled, stress concentration is avoided when the temperature is directly cooled to the room temperature by hot-pressing sintering, and the base body is prevented from generating bubbling, cracking, cracks and other internal hidden injuries. The stress is slowly released in the cooling process, so that the yield of the base body is further ensured.

The technical scheme adopted by the superhard abrasive grinding wheel is as follows:

a superhard abrasive grinding wheel using the high-speed grinding substrate is disclosed.

The superhard abrasive grinding wheel with the high-speed grinding substrate still has a good grinding effect when the grinding speed is more than 120 m/s.

Drawings

FIG. 1 is a schematic cross-sectional view of a high-speed grinding substrate according to the present invention;

FIG. 2 is a schematic view of a high-speed grinding wheel produced using the high-speed grinding substrate of the present invention.

Detailed Description

The invention is further described with reference to the following specific embodiments and the accompanying drawings.

Embodiments of grinding wheel base body for high-speed grinding