阅读说明：本技术 一种320目以细金属结合剂金刚石弹性磨块及其制备方法 (Elastic diamond grinding block with 320-mesh fine metal binding agent and preparation method thereof ) 是由 冯海洲 张洪喜 刘益刚 乔翠娅 李博 任学军 于 2020-06-29 设计创作，主要内容包括：一种320目以细金属结合剂金刚石弹性磨块及其制备方法。其特征在于：其包括由上至下依次连接的刀头、橡胶垫块、卡座；所述刀头为金属粉末与金刚石的烧结体,所述金属粉末中包含有Cu-Sn-Bi-P预合金粉末,所述Cu-Sn-Bi-P预合金粉末通过雾化法制备而成,其按重量比例计,Sn为7~20%、Bi为8~30%、P为1~5%,余量为Cu；所述金刚石采用325目以细金刚石,金刚石体积浓度为10%~30%,投料系数0.9~1.0。其优点在于填补了金属结合剂金刚石磨块在320目以细的磨块领域的应用空白,大幅提高使用寿命,磨削加工过程中基本无磨削残余物,环保无污染。(A diamond elastic grinding block with 320 meshes of fine metal bond and a preparation method thereof. The method is characterized in that: the tool bit, the rubber cushion block and the clamping seat are sequentially connected from top to bottom; the tool bit is a sintered body of metal powder and diamond, the metal powder comprises Cu-Sn-Bi-P prealloying powder, the Cu-Sn-Bi-P prealloying powder is prepared through an atomization method, and the Cu-Sn-Bi-P prealloying powder comprises, by weight, 7-20% of Sn, 8-30% of Bi, 1-5% of P and the balance of Cu; the diamond is 325-mesh fine diamond, the volume concentration of the diamond is 10% -30%, and the feeding coefficient is 0.9-1.0. The method has the advantages of filling the application blank of the metal bond diamond grinding block in the field of grinding blocks with 320 meshes or less, greatly prolonging the service life, basically having no grinding residues in the grinding process, and being environment-friendly and pollution-free.)

1. A320-mesh diamond elastic grinding block with fine metal bond is characterized in that: the tool comprises a tool bit (1), a rubber cushion block (2) and a clamping seat (3) which are sequentially connected from top to bottom; the tool bit (1) is a sintered body of metal powder and diamond, the metal powder comprises Cu-Sn-Bi-P pre-alloy powder, the Cu-Sn-Bi-P pre-alloy powder is prepared by an atomization method, and the Cu-Sn-Bi-P pre-alloy powder comprises, by weight, 7-20% of Sn, 8-30% of Bi, 1-5% of P and the balance of Cu; the diamond adopts 320 meshes to be fine diamond.

2. The 320 mesh fine metal bond diamond resilient grinding block of claim 1, wherein: the laser particle size D50 of the average particle size of the Cu-Sn-Bi-P prealloyed powder is 5-15 mu m, and the D97 value of the coarse particle size is not more than 32 mu m.

3. The 320 mesh fine metal bond diamond resilient grinding block of claim 1, wherein: the Cu-Sn-Bi-P prealloyed powder is prepared by a water atomization method and comprises the following steps: sequentially adding Cu, Sn, Bi and P into a smelting furnace, electrifying for melting and refining, deoxidizing by adding carbon powder, pouring into a tundish when the superheat degree of molten liquid is adjusted to be 150-200 ℃, smashing molten steel by high-pressure water after molten steel passes through a ladle bottom hole, atomizing into powder under the condition of filling nitrogen protection, dehydrating the powder after atomization by vacuum filtration, drying in a drying box for 4-10 hours, reducing by using mixed hydrogen and nitrogen, sieving the reduced powder by using a sieve, and fully mixing the sieved powder in a powder batch machine.

4. The 320 mesh fine metal bond diamond resilient grinding block of claim 1, wherein: the Cu-Sn-Bi-P prealloying powder is produced and prepared by a water-gas combined atomization method, and comprises the following steps: sequentially adding Cu, Sn, Bi and P into a smelting furnace, electrifying for melting and refining, deoxidizing by adding carbon powder, pouring into a tundish when the superheat degree of molten liquid is adjusted to be 150-200 ℃, crushing molten steel by combining high-purity nitrogen flow and high-pressure water after passing through a ladle bottom hole, dehydrating the atomized powder by vacuum filtration, drying in a drying box for 4-10 hours, reducing by using mixed hydrogen and nitrogen, sieving the reduced powder by using a sieve screen, and fully mixing the sieved powder in a powder batch machine.

5. The 320-mesh fine metal bond diamond resilient grinding block of claim 3 or 4, wherein: the reduction of the hydrogen-nitrogen mixture is carried out in a stepping pushing boat reduction furnace, the volume ratio of hydrogen in the hydrogen-nitrogen mixture is 75%, the reduction temperature of the hydrogen-nitrogen mixture is 400-650 ℃, the pushing boat amount in the stepping pushing boat reduction furnace is 5-10 kg/boat, the pushing speed is 5-10 minutes/boat, and the screen is a 500-mesh screen.

6. The 320 mesh fine metal bond diamond resilient grinding block of claim 1, wherein: the clamping seat (3), the rubber cushion block (2) and the tool bit (1) are bonded through high-strength glue.

7. The 320 mesh fine metal bond diamond resilient grinding block of claim 1, wherein: the top surface and the bottom surface of the tool bit (1) are both cambered surfaces.

8. The 320 mesh fine metal bond diamond resilient grinding block of claim 1, wherein: the tool bit (1) sets up a plurality ofly to along rubber cushion (2) up end middle part linear arrangement, leave the equidistance clearance between the tool bit (1) that faces mutually, every tool bit (1) both ends are fillet transition.

9. The 320 mesh fine metal bond diamond resilient grinding block of claim 1, wherein: the cutter head (1) is of an integral structure, the width of the cutter head (1) is gradually reduced from one end to the other end of the cutter head, and the peripheries of the tops of all the cutter heads (1) are in round angle transition.

10. A method for preparing a 320 mesh fine metal bond diamond resilient abrasive grain as claimed in any one of claims 1 to 9, wherein: comprises the steps of

1) Adding a wetting agent into the metal powder and the diamond, and fully mixing;

2) putting the mixed material into a graphite die, and sintering by adopting a powder metallurgy method to prepare a grinding block cutter head (1);

3) sequentially bonding the clamping seat (3), the rubber cushion block (2) and the tool bit (3) by high-strength glue to prepare a diamond grinding block;

4) and performing edging treatment to obtain a finished product of the diamond elastic grinding block.

Technical Field

The invention relates to the technical field of grinding tools, in particular to a 320-mesh diamond elastic grinding block with fine metal bond and a preparation method thereof, which are mainly applied to surface grinding and polishing of natural stone, artificial stone and ceramic materials.

Background

At present, the fine (320 meshes or finer) grinding blocks for grinding and polishing hard and brittle materials such as ceramics, stones and the like are all resin grinding blocks or magnesia grinding blocks, and have the following defects: the service life is short, each group has the service life of 2-3 hours, and needs to be replaced frequently, so that the grinding efficiency is low, and the labor cost is high; a large amount of waste water and waste residue are generated in the grinding and polishing process, the environmental pollution is great, and the treatment cost of processing residues is high. Therefore, in these engineering application fields, development of a highly efficient and environmentally friendly grinding block having a long service life and less grinding residue is demanded.

The metal bond grinding block is also applied to the market of a coarse grinding block (36-180 meshes) due to the advantages of long service life, small pollution and the like, but the mature metal bond grinding block applied to the market at present can only be used for 180 meshes, a small number of 240-mesh metal bond grinding blocks made of specific materials can also be applied, but the number is very small, and the 320-mesh fine grinding block cannot use metal bond, and only resin or magnesia bond with extremely short service life can be adopted.

The reason is that the existing metal bond sintered tyre body has the contradiction that the mechanical property and the wear property are difficult to be blended: if the matrix is required to maintain enough holding force on the diamond (the matrix has good mechanical property: high strength), the hardness of the matrix is high (more than HRB 70) and the wear resistance is strong, so that the fine-particle diamond cannot be edged or the edging height is insufficient, and the grinding block cannot be used due to the absence of grinding force; if the hardness and the abrasiveness of the matrix are reduced, the sintering density and the strength of the matrix are reduced, and the diamond cannot be effectively held, so that the failure is caused. The contradiction is a key restriction bottleneck which always prevents the application of the 320-mesh fine metal bond diamond grinding block in the industry, and needs to be overcome. How to obtain the sintered matrix with high density, low hardness, moderate strength, fine structure and strong self-sharpening abrasion stripping capability is the key for solving the contradiction, which depends on the component design, the preparation process and the performance regulation of the metal bond powder. Therefore, the method for preparing the 320-mesh fine grinding block by using the fine particle powder with good sintering performance of the matrix, low sintering hardness (less than or equal to HRB 70) and strong self-sharpening abrasion capability is an effective technical approach for solving the contradiction and is also an urgent need for industrial development.

Meanwhile, in the structural form, the existing metal bond grinding block is formed by mechanically combining an integral sintered block formed by mixing metal powder and diamond with an inelastic hard base, a certain pressure is required to be applied to the grinding block to keep the grinding block in close contact with the surface to be processed when the grinding block works, and the working grinding surface of the grinding block is in rigid contact with the surface to be processed, so that the rigid contact cannot effectively release the complex stress state of the surface of the object to be processed slowly, and the problems of mechanical scratch, friction blackening, pressure-induced fracture and the like of the surface to be processed are easily caused.

Disclosure of Invention

In order to overcome the defects of the background technology, the invention provides a diamond elastic grinding block with 320 meshes of fine metal bond and a preparation method thereof.

The technical scheme adopted by the invention is as follows: a320-mesh fine metal bond diamond elastic grinding block comprises a tool bit, a rubber cushion block and a clamping seat which are sequentially connected from top to bottom; the tool bit is a sintered body of metal powder and diamond, the metal powder comprises Cu-Sn-Bi-P prealloying powder, the Cu-Sn-Bi-P prealloying powder is prepared through an atomization method, and the Cu-Sn-Bi-P prealloying powder comprises, by weight, 7-20% of Sn, 8-30% of Bi, 1-5% of P and the balance of Cu; the diamond adopts 320 meshes to be fine diamond.

The laser particle size D50 of the average particle size of the Cu-Sn-Bi-P prealloyed powder is 5-15 mu m, and the D97 value of the coarse particle size is not more than 32 mu m.

The Cu-Sn-Bi-P prealloyed powder can be prepared by a water atomization method, and comprises the following steps: sequentially adding Cu, Sn, Bi and P into a smelting furnace, electrifying for melting and refining, deoxidizing by adding carbon powder, pouring into a tundish when the superheat degree of molten liquid is adjusted to be 150-200 ℃, smashing molten steel by high-pressure water after molten steel passes through a ladle bottom hole, atomizing into powder under the condition of filling nitrogen protection, dehydrating the powder after atomization by vacuum filtration, drying in a drying box for 4-10 hours, reducing by using mixed hydrogen and nitrogen, sieving the reduced powder by using a sieve, and fully mixing the sieved powder in a powder batch machine.

The Cu-Sn-Bi-P prealloyed powder can also be produced by adopting a water-gas combined atomization method, and comprises the following steps: sequentially adding Cu, Sn, Bi and P into a smelting furnace, electrifying for melting and refining, deoxidizing by adding carbon powder, pouring into a tundish when the superheat degree of molten liquid is adjusted to be 150-200 ℃, crushing molten steel by combining high-purity nitrogen flow and high-pressure water after passing through a ladle bottom hole, dehydrating the atomized powder by vacuum filtration, drying in a drying box for 4-10 hours, reducing by using mixed hydrogen and nitrogen, sieving the reduced powder by using a sieve screen, and fully mixing the sieved powder in a powder batch machine.

The reduction of the hydrogen-nitrogen mixture is carried out in a stepping pushing boat reduction furnace, the volume ratio of hydrogen in the hydrogen-nitrogen mixture is 75%, the reduction temperature of the hydrogen-nitrogen mixture is 400-650 ℃, the pushing boat amount in the stepping pushing boat reduction furnace is 5-10 kg/boat, the pushing speed is 5-10 minutes/boat, and the screen is a 500-mesh screen.

The Cu-Sn-Bi-P pre-alloy powder adopts a high-temperature liquid smelting and atomizing method, soft Bi element with low melting point and P element capable of forming a brittle phase with Cu are introduced into Cu-Sn binary alloy, and a mechanical mixture of Cu, Sn and Bi atom clusters and brittle Cu6Sn5 and Cu3P compounds is formed inside powder particles, so that a traditional copper-based alloy system is broken through to form a new product.

The Cu-Sn binary alloy can form a solid solution with high strength and good toughness (the Cu content is usually less than or equal to 15%) according to different weight proportions of the Cu-Sn binary alloy and the Cu-Sn binary alloy, and can also form a mixture phase system of the solid solution with low strength and high brittleness and a hard brittle phase Cu6Sn5 and the like (the Cu content is usually more than 15%).

Cu and Bi are basically not in solid solution, a cooling aggregate is a segregation mixed phase of the Cu and the Bi, solid powder with Bi region segregation is obtained under the atomization quenching condition by increasing the Bi content, soft Bi with a low melting point has good solid-phase lubrication effect, the sintering temperature of Cu-Sn binary alloy powder can be reduced, the sintering hardness is remarkably reduced, particularly, when the soft Bi and Cu form a segregation structure, the solid lubrication effect is more favorably exerted, and therefore the mixed sintered phase of the solid solution and the brittle phase with low sintering temperature, high brittleness and low toughness is obtained, and the abrasive property of a powder sintering matrix is weakened/reduced.

On the basis of Cu-Sn-Bi, 1-5% of P element is added, and brittle compounds such as Cu3P and the like can be formed between Cu and P to further reduce the sintering temperature, refine the sintering structure and obtain a brittle phase Cu3P, so that the brittle wear behavior of the powder sintered matrix is enhanced, and the wear stripping speed is accelerated.

The Cu-Sn-Bi-P prealloying powder is a refined sintered physical phase structure which is high in compactness, low in sintering temperature, low in hardness, high in brittleness and easy to abrade and strip, so that the prepared 320-mesh fine metal binding agent diamond elastic grinding block not only can keep enough holding force of a matrix on diamond, but also is easy to rapidly abrade by self sharpening, enables the diamond to be continuously sharpened, improves the sharpness of a tool, can replace the application of the existing magnesia binding agent or resin binding agent in the 320-mesh fine diamond grinding block, and is long in service life, green and pollution-free.

The clamping seat, the rubber cushion block and the tool bit are formed by bonding high-strength glue, the rubber cushion block has elasticity, the grinding block is in elastic contact with a working grinding surface of the grinding block when in working, the elastic deformation of the rubber can be utilized to buffer/reduce and adjust grinding machining stress, good contact between the grinding block and a machined surface can be kept, the machined surface can be protected from being worn, and therefore grinding quality is effectively improved, and grinding yield is remarkably improved.

The top surface and the bottom surface of the tool bit are both arc surfaces, the radius of the top arc surface is matched with the swing radius of the swing arm of the grinding machine, the bottom arc surface is matched with the radian of the rubber cushion block, and the radius of the top arc surface of the grinding block is matched with the swing radius of the swing arm of the grinding machine, so that the grinding block can be effectively kept in a linear contact state with the surface of a processed workpiece all the time in the grinding swing working process, and the grinding sharpness of the grinding block can be obviously improved; the design that bottom cambered surface and rubber cushion radian match can effectively improve the inseparable bonding strength between the two, prevents that the abrasive brick from often taking place the phenomenon that bonding surface fracture and drop between with the rubber cushion when long-time during operation to guarantee the effective life of abrasive brick.

The tool bit can set up a plurality ofly to along rubber cushion up end middle part linear arrangement, leave the equidistance clearance between the tool bit adjacent mutually, increased the chip removal space when polishing, further guarantee the continuous working ability of abrasive brick, every tool bit both ends are the fillet transition, can effectively avoid the edge scratch, guarantee good polishing quality.

The cutter head can also be of an integral structure, the width of the cutter head is gradually reduced from one end of the cutter head to the other end of the cutter head, the cutter head has better overall stability, the cutter head can be synchronously worn on different grinding and polishing radiuses due to the change of the width, the peripheries of the tops of all the cutter heads are in round-corner transition, the edge scratch can be effectively avoided, and the excellent grinding and polishing quality is ensured.

The preparation method of the 320-mesh fine metal bond diamond elastic grinding block comprises the following specific steps:

1) adding a wetting agent into the metal powder and the diamond, and fully mixing;

2) loading the mixed material into a graphite die, and sintering by adopting a powder metallurgy method to prepare a grinding block cutter head;

3) sequentially bonding the clamping seat, the rubber cushion block and the tool bit by using high-strength glue to prepare a diamond grinding block;

4) and performing edging treatment to obtain a finished product of the diamond elastic grinding block.

The invention has the beneficial effects that:

1. the Cu-Sn-Bi-P prealloying powder has the characteristics of fine granularity, low sintering temperature, fine structure, high density, low hardness, high brittleness, easy abrasion and peeling and the like, not only can keep enough holding force of a matrix on diamond, but also is easy to rapidly and self-sharpen abrade, so that the diamond can be continuously sharpened, the sharpness of a tool is improved, the mutual adjustment between the mechanical property and the abrasion property of a metal binding agent sintered matrix is realized, and the application blank of a metal binding agent diamond grinding block in the field of 320-mesh fine grinding blocks is filled;

2. the service life of the resin elastic grinding block is more than 20 times of that of the traditional resin elastic grinding block, the frequency of replacing the grinding block manually can be greatly reduced, the production efficiency is obviously improved, and the labor cost is reduced;

3. the abrasion loss of the tire body in unit time is extremely low, and abrasion dust pollution is hardly generated in the continuous working process, so that the pollution of a large amount of slurry generated by the traditional resin binder grinding block is completely avoided, and the green and environment-friendly production is basically realized;

4. nearly pure abrasive dust of a processed workpiece generated in the grinding and polishing process can be recycled, so that the processing cost is reduced, the environmental pollution caused by pollution discharge is greatly reduced, and the technical upgrading and the environment-friendly production in the related production field are greatly promoted.

Drawings

FIG. 1 is a scanning electron microscope image of Cu-Sn-Bi-P prealloyed powder particles.

FIG. 2 is a scanning electron microscope morphology of a Cu-Sn-Bi-P prealloyed powder sintered structure.

FIG. 3 is a scanning electron microscope topography of Cu-Sn-Bi-P pre-alloyed powder sintered structure diamond-impregnated.

Fig. 4 is a schematic structural diagram of a seven-metal bond diamond elastic grinding block in an embodiment of the invention.

Fig. 5 is a schematic structural diagram of a nine-metal bond diamond elastic grinding block according to an embodiment of the invention.

Detailed Description