阅读说明：本技术 钎焊混合料及由其制备金刚石钎焊串珠的方法 (Brazing mixture and method for preparing diamond brazing bead string by using same ) 是由 佘直昌 周斌 杨跃飞 唐汇德 甄春刚 覃光明 于 2021-11-03 设计创作，主要内容包括：一种钎焊混合料,包括：钎焊粉和/或细颗粒合金粉末、改性剂和成形剂,所述改性剂由碳化钨、二硼化钛、碳化钛或碳化铬中一种或两种与碳化二钼组成的高硬度粉末,其用量为钎焊粉或细颗粒合金粉末质量的5～20％(W/W)；所述成形剂为占钎焊粉末或细颗粒合金粉末质量的2.5～4.5％的石蜡、PEG、PVA、丙烯酸树脂中的一种或两种溶液。该钎焊混合料加入碳化二钼与碳化钨、二硼化钛、碳化钛或碳化铬等,以调节胎体的耐磨性,同时可改善烧结效果；便于快速调节胎体中的金刚石浓度,可以实现高效切割。本发明还公开了一种制备金刚石钎焊串珠的方法,通过高效球磨、去应力、脱氧、造粒等,改变钎焊粉末粒度与形貌,改善混合料的压制性能,以冷压成形方式快速制备钎焊串珠。(A brazing compound comprising: the brazing powder and/or fine-particle alloy powder, the modifier and the forming agent are/is high-hardness powder consisting of one or two of tungsten carbide, titanium diboride, titanium carbide and chromium carbide and dimolybdenum carbide, and the dosage of the high-hardness powder is 5-20% (W/W) of the mass of the brazing powder or the fine-particle alloy powder; the forming agent is one or two solutions of paraffin, PEG, PVA and acrylic resin accounting for 2.5-4.5% of the mass of the brazing powder or the fine-particle alloy powder. The brazing mixture is added with dimolybdenum carbide, tungsten carbide, titanium diboride, titanium carbide or chromium carbide and the like to adjust the wear resistance of the matrix and improve the sintering effect; the diamond concentration in the matrix is convenient to rapidly adjust, and efficient cutting can be realized. The invention also discloses a method for preparing the diamond brazing bead, which changes the granularity and the appearance of brazing powder, improves the pressing performance of a mixture and quickly prepares the brazing bead in a cold pressing forming mode through efficient ball milling, stress removal, deoxidation, granulation and the like.)

1. A brazing compound comprising: the brazing powder and/or fine-particle alloy powder, the modifier and the forming agent are characterized in that the modifier is high-hardness powder consisting of one or two of tungsten carbide, titanium diboride, titanium carbide and chromium carbide and dimolybdenum carbide, and the dosage of the high-hardness powder is 5-20% (W/W) of the mass of the brazing powder or the fine-particle alloy powder; the forming agent is one or two solutions of paraffin, PEG, PVA and acrylic resin accounting for 2.5-4.5% of the mass of the brazing powder or the fine-particle alloy powder.

2. A method of making a diamond braze bead, the method comprising the steps of:

firstly, preparing a brazing mixture: the braze compound is as recited in claim 1;

secondly, mixing the brazing mixture with the diamond: mixing the granulated material obtained in the step one with diamond for 0.3-1 h to obtain a mixture to be pressed;

thirdly, forming a bead string pressed compact;

fourthly, sintering the beads: and the diamond beads are degreased and sintered in a vacuum atmosphere.

3. The method of making a diamond braze bead according to claim 2, wherein the braze powder is a copper alloy braze powder or a nickel alloy braze powder, and the preparation of the braze compound comprises the steps of:

1) the brazing powder is prepared by grinding 200-mesh brazing powder to 300-400-mesh by adopting a planetary ball mill under the regulation of vacuum and inert gas protection, and then performing stress relief annealing at the temperature of 600-720 ℃ in vacuum or hydrogen atmosphere;

2) uniformly mixing the powder prepared in the step 1) with high-hardness powder, adding a forming agent, crushing or stirring for granulation, and passing through a 30-200-mesh screen after a solvent is volatilized to obtain a granulated material for later use; and crushing and screening the materials on the screen to obtain granulation materials, and granulating the material powder below the screen in a hot melting or solvent adding mode to obtain the granulation materials with the required granularity.

4. The method of making a diamond braze bead according to claim 2, wherein the preparation of the braze compound includes the steps of:

1) ball-milling fine-particle alloy powder containing carbide elements, then preserving heat at the temperature of 600-720 ℃ in vacuum or hydrogen atmosphere for 1-1.5 hours to remove stress and deoxidize; mixing with high hardness powder; or mixing fine alloy powder containing carbide elements with the grain size of less than or equal to 400 meshes with high-hardness powder;

2) uniformly mixing the powder prepared in the step 1) with a forming agent, and granulating to obtain 30-200-mesh granules.

5. The method for preparing diamond braze beads according to claim 4, wherein 5-25% of 200-mesh atomized brazing powder is added in the step 1).

6. The method for preparing diamond brazing beads according to claim 2, wherein in the second step, the concentration of the diamond is 30-200%, and 0.5-1.5% of a release agent in mass fraction of powder is added.

7. The method for preparing diamond braze beads according to claim 2, wherein the specific operation of the third step is as follows: and D, cold pressing and forming the mixture to be pressed in the step II on a press, wherein the powder is directly pressed on the steel matrix during pressing, and the forming pressure is 100-350 MPa.

8. The method of manufacturing diamond braze beads according to claim 2, wherein in step three, the substrate is 45# steel and is treated with copper plating or nickel plating; the outer side of the base body is provided with a radial groove, and one side of the end part of the radial groove extends out of a circular step; after pressing, the powder was attached to the surface of the substrate.

9. The method for preparing diamond brazing beads according to claim 2, wherein the brazing mixture is copper alloy brazing powder or fine-particle copper alloy powder, the sintering vacuum degree is less than or equal to 0.002Pa, and the sintering temperature is 880-940 ℃; the working parameters of the specific degreasing and sintering phases are as follows:

10. the method for preparing diamond brazing beads according to claim 2, wherein the brazing mixture is nickel alloy brazing powder, the vacuum degree is less than or equal to 0.05Pa, and the sintering temperature is 1020-1080 ℃; the working parameters of the specific degreasing and sintering phases are as follows:

Technical Field

The invention relates to the field of manufacturing of brazed diamond tools, in particular to a brazing mixture and a method for preparing diamond brazed beads by using the same.

Background

At present, the commonly used diamond beads mainly comprise two types of sintered diamond beads and brazed diamond beads, wherein the sintered diamond beads have longer service life but low cutting efficiency, the brazed diamond beads have high cutting efficiency but short actual service life, the service life and the cutting efficiency of the sintered diamond beads and the brazed diamond beads are different, and in some aspects, the service life of the beads and the cutting efficiency have opposite property; in part, sintered diamond beads have a usage complementarity with brazed diamond beads.

The diamond is in a covalent bond structure, and the interfacial energy between the diamond and the common metal is higher, so that high-strength interfacial bonding is difficult to form between the diamond and the common metal. Therefore, how to improve the bonding force between diamond and the matrix is the focus of diamond tool research. The most common ways to improve the bonding force between diamond and the matrix mainly comprise diamond plating, diamond roughening treatment, adding active elements into the matrix, selecting matrix metal with increased matrix specific volume during sintering and cooling, improving the sintering way and the like, wherein the bonding force between the diamond and the matrix can be effectively improved by adding active carbide elements.

At present, based on good wettability of copper, nickel and diamond, active elements such as Ti, Cr, Mo and W are added to the copper or nickel by means of flowing and diffusion of high-temperature molten liquid of the copper or nickel so as to form carbide with the diamond, so that the interface bonding force between a matrix and the diamond is improved. The existing brazing diamond bead takes brazing powder or brazing paste as a matrix raw material, is generally prepared in a powder scattering or paste coating and multiple feeding mode, has low production efficiency, is difficult to produce in large batch and has high production cost.

CN 111687509A discloses a vacuum brazing diamond compound abrasive and application thereof in manufacturing a multilayer diamond vacuum repent welding tool, wherein the compound abrasive is prepared by mixing Cu-Sn-Cr-Ti-Fe-Ni mixed metal powder, a framework material and diamond, and the compound abrasive has good forming performance, is suitable for diamond brazing sintering in filling, coating and other modes, is not suitable for compression molding, has low production efficiency and is difficult to meet the requirement of mass production.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the defects of the prior art are overcome, the brazing mixture which is suitable for cold press molding, simple in preparation process and convenient for diamond concentration adjustment is provided, the feeding mode of the existing brazing powder is further changed, and meanwhile, the invention discloses a preparation method of the brazing mixture.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a brazing compound comprising: the brazing powder and/or fine-particle alloy powder, the modifier and the forming agent are/is high-hardness powder consisting of one or two of tungsten carbide, titanium diboride, titanium carbide and chromium carbide and dimolybdenum carbide, and the dosage of the high-hardness powder is 5-20% (W/W) of the mass of the brazing powder or the fine-particle alloy powder; the forming agent is one or two solutions of paraffin, PEG, PVA and acrylic resin accounting for 2.5-4.5% of the mass of the brazing powder or the fine-particle alloy powder.

The brazing powder is copper alloy brazing powder or nickel alloy brazing powder; the preparation method of the brazing mixture comprises the following steps: the method comprises the following steps:

1) the brazing powder is prepared by grinding 200-mesh brazing powder to 300-400-mesh by adopting a planetary ball mill under the regulation of vacuum and inert gas protection, and then performing stress relief annealing at the temperature of 600-720 ℃ in vacuum or hydrogen atmosphere;

2) uniformly mixing the powder prepared in the step 1) with high-hardness powder, adding a forming agent, crushing or stirring for granulation, and passing through a 30-200-mesh screen (0.075 mm-0.6 mm) after a solvent is volatilized to obtain a granulated material for later use; and granulating the material powder below the screen by hot melting or adding a solvent to obtain the granulated material with the required granularity.

In one exemplary embodiment, the method of preparing the brazing compound comprises: the method comprises the following steps:

1) the fine particle alloy powder is mixed with a titanium-containing compound and then ball milled, such as a powder of Cu: sn: ti ═ 70-80: (12-20): (6-11) mixing to prevent the problem of oxidation of single carbide, and ball-milling to obtain mixed powder with more uniform components, wherein the powder has fine granularity, better formability and better sintering activity; after screening, preserving the heat at the temperature of 600-720 ℃ for 1-1.5 hours in vacuum or hydrogen atmosphere for stress relief and deoxidation; then ball milling and mixing fine particle alloy powder containing carbide elements and high-hardness powder; or mixing fine alloy powder containing carbide elements with the grain size of less than or equal to 400 meshes with high-hardness powder;

2) uniformly mixing the powder prepared in the step 1) with a forming agent, and granulating to obtain 30-200-mesh granules.

Optionally, in the step 1), 5-25% of 200-mesh atomized brazing powder is added.

A method of making a diamond braze bead, the method comprising the steps of:

firstly, preparing a brazing mixture;

secondly, mixing the brazing mixture with the diamond: mixing the granulated material obtained in the step one with diamond for 0.3-1 h to obtain a mixture to be pressed; wherein the diamond concentration is 30-200%, and 0.5-1.5% of release agent in powder mass fraction is added;

thirdly, forming a bead pressing blank: the mixture to be pressed in the step two is subjected to cold pressing forming on a press, powder is directly pressed on the matrix during pressing, and the forming pressure is 100-;

fourthly, sintering the beads: the diamond bead is degreased and sintered in a vacuum atmosphere, the brazing mixture is copper alloy brazing powder or fine-particle copper alloy powder, the sintering vacuum degree is less than or equal to 0.002Pa, and the sintering temperature is 880-940 ℃; the brazing mixture is nickel alloy brazing powder, the vacuum degree is less than or equal to 0.05Pa, and the sintering temperature is 1020-1080 ℃.

In the third step, the matrix is 45# steel and is treated by copper plating or nickel plating. The radial grooves are formed in the outer side of the base body, so that the contact area of the powder and the base body can be increased, and sintering sagging is prevented; one side of the end part of the base body extends out of a round step which can support materials to prevent axial movement and can keep the integrity and regularity of the bead string after sintering. After pressing, the powder is attached to the surface of the matrix, so that the powder is convenient to transfer and is prevented from being damaged, and the matrix does not need to be placed subsequently.

The copper alloy bead is degreased and sintered in a vacuum atmosphere, the vacuum degree is less than or equal to 0.002Pa, and the specific process is as follows:

the nickel alloy bead brazing process is as follows, the vacuum degree is less than or equal to 0.05Pa, and the specific process is as follows:

the brazing mixture has the beneficial effects that:

the fluidity of the brazing mixture is good; and the uniformity of material performance, such as the mixture apparent density and the fluidity, is improved, thereby being beneficial to obtaining the bead string pressed compact with stable quality in the follow-up process.

The brazing mixture changes the granularity and the appearance of brazing powder through efficient ball milling, stress relief, deoxidation, granulation and the like, improves the pressing performance of the mixture, and quickly prepares brazing beads in a cold pressing forming mode.

Because carbide elements are not added in the existing brazing powder, the brazing powder is easy to react with oxygen in the air to form an oxide film, the oxide film is not beneficial to subsequent use, and certain requirements are met for powder storage and use.

The brazing mixture is convenient for quickly adjusting the diamond concentration in the matrix, and the problems that the diamond concentration is difficult to be edged and the service life is short in the later cutting stage of the conventional brazing bead are overcome, so that efficient cutting can be realized, and the service life cannot be reduced.

The brazing mixture and the method for preparing the diamond brazing bead by the method have the advantages that:

according to the brazing mixture, the high-hardness powder is added, wherein tungsten carbide, titanium diboride, titanium carbide or chromium carbide belongs to the high-hardness hard powder, so that the stability is high, and the wear resistance of the material can be greatly improved; dimolybdenum carbide is not as strong or even brittle as compared to other powders, but it has good affinity for the matrix metal. The combination of the two can improve the comprehensive performance of the tire body material.

The method adopts the special brazing mixture which is designed independently and is treated by a specific procedure, so that the stability of the bead string pressed compact is improved obviously.

The method is matched with bead sintering, a bead substrate with a radial groove on the surface is adopted, and one end of the substrate is provided with an annular step, so that the binding force of a matrix layer to the substrate can be increased, and meanwhile, the phenomenon that brazing filler metal sags during sintering and the like is prevented.

Drawings

FIG. 1 is a cross-sectional view of a substrate for use in a method of manufacturing a diamond bead according to the present invention;

in the figure: 1-substrate, 11-radial groove, 12-circular step.

Detailed Description

The invention is further explained with reference to the drawings and the embodiments.

Example 1

The brazing compound of the embodiment comprises: the brazing powder, the modifier and the forming agent are mixed, wherein the modifier is high-hardness powder consisting of tungsten carbide and molybdenum carbide according to the mass ratio of 1:1, and the dosage of the high-hardness powder is 10% (W/W) of the mass of the brazing powder; the forming agent is paraffin gasoline solution with the mass accounting for 4.0 percent of the brazing powder and the concentration accounting for 15 percent.

The brazing powder is BNi₂Nickel alloy brazing powder.

Referring to fig. 1, a method of manufacturing a diamond braze bead of the present embodiment, a method of manufacturing a diamond braze bead, comprising the steps of:

the preparation of the brazing compound comprises the following steps:

1) BNi of 200 meshes₂Ball-milling nickel alloy brazing powder in a planetary ball mill for 10min under the protection of argon, wherein the ball-material ratio is 6:1, the ball-milling rotation speed is 400r/min, the grinding balls are made of silicon nitride, powder is obtained by sieving through a 400-mesh sieve, the material on the sieve is continuously ball-milled until the material passes through the 400-mesh sieve, and the ball-milled powder is subjected to stress relief annealing and deoxidation after being kept at 700 ℃ for 1 hour in a hydrogen atmosphere;

2) mixing the powder prepared in the step 1) with tungsten carbide powder accounting for 5% of the mass of the powder and high-hardness molybdenum carbide powder accounting for 5% of the mass of the powder for 2 hours by using a mixer, and uniformly mixing to obtain mixed powder; then, adding paraffin gasoline solution with concentration of 15% and 4% of the powder as a forming agent, uniformly stirring, granulating by a stirring granulation mode, sieving particles in the middle of a 30-100-mesh screen mesh after a solvent is volatilized for later use as a granulating material, crushing and sieving the material on the 30-mesh screen mesh, agglomerating the powder of the material under the 100-mesh screen mesh by a 80 ℃ hot melting mode, cooling, crushing and sieving.

Secondly, mixing the brazing mixture with the diamond: adding diamond with the actual volume ratio of 25% of powder (namely the diamond concentration is 100%) and magnesium stearate accounting for 1% of the mass fraction of the granulated material into the granulated material obtained in the step one, manually mixing the materials, and mixing the materials in a three-dimensional mixer for 20min to obtain a mixture to be pressed; wherein the diamond concentration is 100%, and 1.0% of release agent in powder mass fraction is added;

thirdly, forming a bead pressing blank: and D, performing cold pressing forming on the mixture to be pressed in the step two on a press, directly pressing the powder on the substrate during pressing, pressing the powder into a bead tire body green compact with the outer diameter phi of 11.6mm, the inner diameter phi of 7.8mm and the height of 7.0mm under the forming pressure of 300 MPa.

Fourthly, sintering the beads: the diamond bead is degreased and sintered in a vacuum atmosphere, the brazing mixture is nickel alloy brazing powder, the vacuum degree is less than or equal to 0.05Pa, the sintering temperature is 1060 ℃, and the specific sintering parameters are as follows:

in the third step, the matrix is 45# steel and is treated by copper plating or nickel plating. The radial grooves are formed in the outer side of the base body, so that the contact area of the powder and the base body can be increased, and sintering sagging is prevented; one side of the end part of the base body extends out of a round step which can support materials to prevent axial movement and can keep the integrity and regularity of the bead string after sintering. After pressing, the powder is attached to the surface of the matrix, so that the powder is convenient to transfer and is prevented from being damaged, and the matrix does not need to be placed subsequently.

Example 2

The brazing compound of the embodiment comprises: brazing powder, a modifier and a forming agent, wherein the modifier is high-hardness powder consisting of titanium diboride and molybdenum carbide according to the mass ratio of 2:1, and the dosage of the high-hardness powder is 15% (W/W) of the mass of the brazing powder; the forming agent is an acrylic acid-methyl methacrylate solution which accounts for 3.5 percent of the mass of the brazing powder and has the concentration of 20 percent.

The brazing powder is CuSnTi10 copper alloy brazing powder.

Referring to fig. 1, a method of manufacturing a diamond braze bead of the present embodiment, a method of manufacturing a diamond braze bead, comprising the steps of:

the preparation of the brazing compound comprises the following steps:

1) ball-milling 200-mesh CuSnTi10 copper alloy brazing powder in a planetary ball mill for 20min under the protection of argon gas, wherein the ball-material ratio is 5:1, the ball-milling rotation speed is 450r/min, the grinding ball is made of silicon nitride, powder is obtained by sieving the powder with a 325-mesh sieve, the material on the sieve is continuously ball-milled until the material passes through the 325-mesh sieve, and the ball-milled powder is subjected to stress relief annealing and deoxidation after being kept at 680 ℃ for 1 hour in a hydrogen atmosphere;

2) mixing the powder prepared in the step 1), 10% of titanium diboride and 5% of molybdenum carbide high-hardness powder in the mass of the powder for 1 hour by using a mixer, and uniformly mixing to obtain mixed powder; then, 3.5 percent of acrylic acid-methyl methacrylate solution with the concentration of 20 percent of the powder is added as a forming agent and uniformly stirred, and then granulation is carried out by a stirring granulation mode, after the solvent is volatilized, particles are screened in the middle of a screen with 40 meshes to 80 meshes to be used as a granulation material for standby, the material on the screen with 40 meshes is crushed and sieved, and the material powder under the screen with 80 meshes is added with 10 percent of methyl methacrylate, uniformly stirred and sealed for a period of time, dried at 80 ℃, cooled, crushed and sieved.

Secondly, mixing the brazing mixture with the diamond: adding 15% of diamond and 0.7% of magnesium stearate in the mass fraction of the granulated material in the actual volume ratio of powder (namely, the diamond concentration is 60%) into the granulated material obtained in the step one, manually mixing the materials, and mixing the materials in a three-dimensional mixer for 25min to obtain a mixture to be pressed;

thirdly, forming a bead pressing blank: and D, cold-pressing and forming the mixture to be pressed in the step two on a press, directly pressing the powder on the matrix during pressing, pressing the mixture into a bead carcass pressed blank with the outer diameter phi 12mm, the inner diameter phi 8.0mm and the height 7.2mm, wherein the forming pressure is 200 Mpa.

Fourthly, sintering the beads: the diamond bead is degreased and sintered in a vacuum atmosphere, the brazing mixture is copper alloy brazing powder, the vacuum degree is less than or equal to 0.002Pa, the sintering temperature is 1060 ℃, and the specific sintering parameters are as follows:

in the third step, the matrix is 45# steel and is treated by copper plating or nickel plating. The radial grooves are formed in the outer side of the base body, so that the contact area of the powder and the base body can be increased, and sintering sagging is prevented; one side of the end part of the base body extends out of a round step which can support materials to prevent axial movement and can keep the integrity and regularity of the bead string after sintering. After pressing, the powder is attached to the surface of the matrix, so that the powder is convenient to transfer and is prevented from being damaged, and the matrix does not need to be placed subsequently.

In the brazing mixture of the embodiment, the titanium diboride belongs to hard powder with high hardness, the stability is high, and the wear resistance of the material can be greatly improved; dimolybdenum carbide is not as strong or even brittle as compared to other powders, but it has good affinity for the matrix metal. The combination of the two can improve the comprehensive performance of the tire body material.

Example 3

The brazing compound of the embodiment comprises: the modifier is high-hardness powder consisting of titanium diboride, chromium carbide and molybdenum carbide according to the mass ratio of 15:1:1, and the using amount of the high-hardness powder is 17% (W/W) of the mass of the fine-particle alloy powder; the forming agent is a PVA aqueous solution with the concentration of 20 percent accounting for 3.8 percent of the mass of the fine-particle alloy powder.

The fine-particle alloy powder is prepared by mixing 300-mesh electrolytic copper powder, 200-mesh tin powder and 200-mesh titanium dihydride powder according to a mass ratio of 72:18: 10.

Referring to fig. 1, a method of manufacturing a diamond braze bead of the present embodiment, a method of manufacturing a diamond braze bead, comprising the steps of:

the preparation of the brazing compound comprises the following steps:

1) mixing 300-mesh electrolytic copper powder, 200-mesh tin powder and 200-mesh titanium dihydride powder according to a mass ratio of 72:18:10 to obtain alloy powder, then ball-milling the alloy powder in a planetary ball mill for 30min by using a silicon nitride ceramic grinding ball under the protection of argon, wherein the ball-material ratio is 5:1, the ball-milling rotating speed is 400r/min, sieving the powder by using a 400-mesh sieve to obtain powder, continuously ball-milling the material on the sieve until the material passes through the 400-mesh sieve, and preserving the heat of the ball-milled powder at 680 ℃ for 1.5 hours in a hydrogen atmosphere to perform stress relief annealing and deoxidation; mixing the powder with 10 percent of titanium diboride, 1 percent of chromium carbide and 1 percent of molybdenum carbide high-hardness powder in mass by a mixer for 1.5 hours, and uniformly mixing;

2) adding 3.8% of PVA solution with the concentration of 20% in the powder prepared in the step 1) as a forming agent into the powder, uniformly stirring the mixture while the mixture is hot, granulating the mixture, sieving the granules in the middle of a 50-120-mesh screen mesh to obtain a granulated material for later use, crushing and sieving the material on the 50-mesh screen mesh, pressing the material powder below the 120-mesh screen mesh into balls by a press, and crushing and sieving the materials.

Secondly, mixing the brazing mixture with the diamond: adding 20% of diamond in the actual volume ratio of powder (namely the diamond concentration is 80%) and 0.5% of magnesium stearate in the mass fraction of the granulated material into the granulated material obtained in the step one, manually mixing the materials, and mixing the materials in a three-dimensional mixer for 30min to obtain a mixture to be pressed;

thirdly, forming a bead pressing blank: and D, performing cold pressing forming on the mixture to be pressed in the step two on a press, directly pressing the powder on the substrate during pressing, pressing to form a bead tire body green compact with the outer diameter phi of 11.2mm, the inner diameter phi of 7.6mm and the height of 7.0mm, wherein the forming pressure is 350 MPa.

Fourthly, sintering the beads: the diamond bead is degreased and sintered in a vacuum atmosphere, the brazing mixture is copper alloy fine particle alloy powder, the vacuum degree is less than or equal to 0.002Pa, the sintering temperature is 920 ℃, and the specific sintering parameters are as follows:

in the third step, the matrix is 45# steel and is treated by copper plating or nickel plating. The radial grooves are formed in the outer side of the base body, so that the contact area of the powder and the base body can be increased, and sintering sagging is prevented; one side of the end part of the base body extends out of a round step which can support materials to prevent axial movement and can keep the integrity and regularity of the bead string after sintering. After pressing, the powder is attached to the surface of the matrix, so that the powder is convenient to transfer and is prevented from being damaged, and the matrix does not need to be placed subsequently.

Example 4

The brazing compound of the embodiment comprises: the copper alloy brazing powder comprises CuSnTi10 copper alloy brazing powder, fine-particle alloy powder, a modifier and a forming agent, wherein the modifier is high-hardness powder consisting of Wu carbonized powder and dimolybdenum carbide according to the mass ratio of 1:2, and the dosage of the high-hardness powder is 12% (W/W) of the mass of the fine-particle alloy powder; the forming agent is an acrylic acid-methyl methacrylate solution with the concentration of 20 percent accounting for 3.0 percent of the mass of the fine-particle alloy powder.

The fine-particle alloy powder is prepared by mixing 300-mesh electrolytic copper powder, 200-mesh tin powder and 200-mesh titanium dihydride powder according to a mass ratio of 60:25: 15.

Referring to fig. 1, a method of manufacturing a diamond braze bead of the present embodiment, a method of manufacturing a diamond braze bead, comprising the steps of:

the preparation of the brazing compound comprises the following steps:

1) mixing 300-mesh electrolytic copper powder, 200-mesh tin powder and 200-mesh titanium dihydride powder according to a mass ratio of 60:25:15 to obtain alloy powder, performing ball milling for 25min in a planetary ball mill under the conditions of vacuum and argon protection, wherein the ball-material ratio is 6:1, the ball milling rotation speed is 400r/min, the grinding balls are silicon nitride ceramics, passing through a 350-mesh screen to obtain powder, continuously performing ball milling on the materials on the screen until the materials pass through the 350-mesh screen, and performing stress relief annealing and deoxidation on the ball-milled powder at 680 ℃ for 1.2 hours in a hydrogen atmosphere;

2) adding 200-mesh CuSnTi10 copper alloy brazing powder (directly purchased without ball milling) accounting for 5% of the mass of the fine-particle alloy powder into the powder prepared in the step 1), and mixing the powder with high-hardness powder of 4% of carbonized Wu and 8% of carbonized dimolybdenum in mass of the powder for 1.5 hours by using a mixer to obtain mixed powder; then, 3.0 percent of acrylic acid-methyl methacrylate solution with the concentration of 20 percent of the powder is added as a forming agent and uniformly stirred, and then granulation is carried out by a stirring granulation mode, after the solvent is volatilized, particles are screened in the middle of a screen with 50 meshes to 100 meshes as a granulation material for standby, the material on the screen with 50 meshes is crushed and sieved, the material powder under the screen with 100 meshes is added with 10 percent of methyl methacrylate, uniformly stirred and sealed for a period of time, dried at 80 ℃, cooled, crushed and sieved.

Secondly, mixing the brazing mixture with the diamond: adding 18% of diamond and 0.6% of magnesium stearate in the mass fraction of the granulated material in the actual volume ratio of powder (namely, the diamond concentration is 72%) into the granulated material obtained in the step one, manually mixing the materials, and mixing the materials in a three-dimensional mixer for 30min to obtain a mixture to be pressed;

thirdly, forming a bead pressing blank: and D, cold-pressing and forming the mixture to be pressed in the step two on a press, directly pressing the powder on the substrate during pressing, pressing the mixture into a bead carcass green compact with the outer diameter phi of 11.8mm, the inner diameter phi of 7.8mm and the height of 7.2mm under the forming pressure of 200 MPa.

Fourthly, sintering the beads: the diamond bead is degreased and sintered in a vacuum atmosphere, the brazing mixture is copper alloy fine particle alloy powder, the vacuum degree is less than or equal to 0.002Pa, the sintering temperature is 900 ℃, and the specific sintering parameters are as follows:

in the third step, the matrix is 45# steel and is treated by copper plating or nickel plating. The radial grooves are formed in the outer side of the base body, so that the contact area of the powder and the base body can be increased, and sintering sagging is prevented; one side of the end part of the base body extends out of a round step which can support materials to prevent axial movement and can keep the integrity and regularity of the bead string after sintering. After pressing, the powder is attached to the surface of the matrix, so that the powder is convenient to transfer and is prevented from being damaged, and the matrix does not need to be placed subsequently.

According to the hardness of diamond beads in the field of application of diamond, the modifier can also be a composition of titanium carbide and dimolybdenum carbide in a mass ratio of 2:1, a composition of tungsten carbide, titanium diboride and dimolybdenum carbide in a mass ratio of 1:1:2, and the like; the above technical features can be understood and implemented by those skilled in the art through the text description, and therefore, the accompanying drawings are not needed to be described.