阅读说明：本技术 一种金刚石绳锯串珠高冷压成型的工艺 (High-cold-press molding process for diamond wire saw bead string ) 是由 高忠麟 于 2019-11-12 设计创作，主要内容包括：一种金刚石绳锯串珠高冷压成型的工艺,包括以步骤(1)-(6)；其中步骤(4)将带铁芯的串珠毛坯装入分体式组合压模具中,由液压机对该高压分体式组合模具进行压制成型；液压机压力设定为：10000-15000kg/cm<Sup>2</Sup>,保压；若干所述模具分体相邻依次结合形成模具主体；所述模具分体上设有若干个分体缺口,相邻位置模具分体之间的分体缺口结合形成用于放置串珠毛坯的模腔。本冷高压成型工艺,通过独特设计的分体式组合冷压模具,实现了分体式组合模具在高冷压时,冷压胎体毛坯出模时分体组合模具侧压泄压后,金刚石串珠胎体与模具腔体的摩擦力极大的减少,降低了珠胎体出模时对模腔的压力和磨损程度,大大提高了模具的使用寿命。(A high-cold press molding process of diamond wire saw beads comprises the following steps (1) - (6); wherein, the step (4) loads the blank of the string of beads with the iron core into the sub-separatorIn the split combined pressing die, the high-pressure split combined die is pressed and formed by a hydraulic machine; the hydraulic press pressure is set as: 10000-15000kg/cm 2 Maintaining the pressure; a plurality of the die split bodies are adjacently and sequentially combined to form a die main body; the split dies are provided with a plurality of split notches, and the split notches between the die split bodies at adjacent positions are combined to form a die cavity for placing the bead blank. This cold high pressure forming technology, through the split type combination cold pressing die of unique design, realized split type assembling die when the high cold pressing, split type assembling die side pressure release back when colding pressing matrix blank demolding, the very big reduction of frictional force of diamond string bead matrix and mould cavity has reduced pressure and the degree of wear of die cavity when the bead matrix demolding, has improved the life of mould greatly.)

1. The high-cold press molding process of the diamond wire saw bead string is characterized by comprising the following steps of:

(1) adding lubricant and matrix alloy powder, mixing and stirring, adding diamond, and continuously mixing and stirring to prepare matrix powder;

(2) placing the prepared carcass powder and the iron core in an automatic press for prepressing and molding to form an integrally molded primary blank;

(3) putting the primary blank into a primary pressing die for pre-pressing and forming, maintaining the pressure to obtain the bead blank with the iron core, and precooling the pressure to 250 plus 500kg/cm²；

(4) Loading the blank of beads with iron core into split combined die, and pressurizing the high-pressure split combined die by hydraulic pressCold pressing and molding; the hydraulic press pressure is set as: 10000-15000kg/cm²Maintaining the pressure; this split type assembling die of high pressure includes: the die comprises a die split body, an upper pressure head, a lower pressure head and a die frame; a plurality of the die split bodies are adjacently and sequentially combined to form a die main body; the die split bodies are provided with a plurality of split gaps, and the split gaps between the die split bodies at adjacent positions are combined to form a die cavity for placing the bead blank; the upper end of the bead blank is contacted with the upper pressure head, and the lower end of the bead blank is contacted with the lower pressure head; two sides of the die main body are arranged in the die frame in an adjustable and elastic manner;

(5) ejecting the bead tire body from the split combined pressing mold, and separating to obtain a diamond bead blank;

(6) and sintering the blank of the diamond bead string to obtain the diamond wire saw bead string.

2. The high-cold press molding process of diamond wire saw beads according to claim 1, wherein in the step (1), the raw materials of the carcass powder comprise: 35-40% of diamond, 59-64% of matrix alloy powder and 0.5-1% of lubricant.

3. The high-cold press molding process of diamond wire saw beads as claimed in claim 2, wherein in the step (1), the matrix alloy powder comprises: 50-65% of Cu-Sn15, 10-15% of electrolytic Cu powder, 10-15% of carbonyl Ni powder, 1-3% of Sn powder, 7-12% of WC powder and 1-3% of Mo powder.

4. The high-cold press molding process of diamond wire saw beads according to claim 2, wherein the granularity ratio of diamond is as follows:

35-40 meshes: 8 to 12 percent;

40-45 meshes: 50-60 percent;

45-50 meshes: 25 to 35 percent;

50-60 meshes: 3 to 7 percent.

5. The high-cold press molding process of diamond wire saw beads according to claim 3, wherein the process comprisesIn the step (1), the density of the matrix powder is 8.00-8.50g/cm³。

6. The high-cold press molding process of diamond wire saw beads as claimed in claim 1, wherein in the step (6), the sintering mode is vacuum sintering, which comprises: heating to room temperature when the vacuum degree is 1Pa, heating to 300 deg.C from room temperature at a heating rate of 100 deg.C/hr, maintaining at 300 deg.C for 0.5-1.0 hr, and removing the residual lubricant; then heating from 300 ℃ to 950 ℃, heating at a speed of 250 ℃/h and a vacuum degree of less than 1Pa, keeping the temperature of 950 ℃ for 1-1.5 h, keeping vacuum and naturally cooling to room temperature, and discharging.

7. The high-cold press molding process of diamond wire saw beads according to claim 1, wherein in the step (6), the sintering mode is vacuum pressure integrated sintering, and the specific steps are as follows: firstly, the furnace body is vacuumized to 1Pa, residual gas in the furnace is removed for 0.5 to 1.0 hour, then hydrogen is added to 500Pa, the lubricant in the blank is removed, metal powder is reduced, the temperature is kept at 300 ℃ for 0.5 to 1.0 hour, and the residual lubricant is removed;

vacuum sintering at 300-950 deg.C with vacuum degree less than 1Pa, heating rate of 250 deg.C/hr, vacuum sintering at 950 deg.C for 0.5-1.0 hr, adding argon gas at 950 deg.C under 6MPa, maintaining for 0.5-1.0 hr, cooling to room temperature, and discharging.

8. The high-pressure cold press molding process for diamond wire saw beads according to any one of claims 1 to 7, wherein the high-pressure split type combination die further comprises: a horizontal mode locker; the horizontal mold locker is arranged on the mold frame, and a telescopic pressing end is arranged in the accommodating groove; the telescopic pressing end is connected to one side of the die main body and used for pressing the die main body to the die frame.

9. The high-cold press molding process of diamond wire saw beads according to claim 7, wherein the horizontal die locker is a die locking hydraulic press with pressureNot less than 20 tons/cm²。

10. The process of claim 8, wherein the high pressure split die is fed into and pushed out of the die frame by a horizontal telescopic driver.

Technical Field

The invention relates to the technical field of diamond wire saw beads, in particular to a high-cold-press molding process of diamond wire saw beads.

Background

The manufacturing process of domestic traditional diamond instrument can satisfy the requirement of cold pressing to feed more than 2 to the loose dress ratio that the alloy powder required, if the loose dress ratio is less than 2 the die cavity of feeding can be very dark, and the distance that the blank was pushed out after the die mould increases, can aggravate the life who makes the mould to the wearing and tearing of mould and shorten greatly. The traditional forming process has the requirements on the alloy powder, the addition proportion of the pre-alloy powder cannot be too large, and the wear degree of a die is large due to small plasticity of the pre-alloy powder and the alloy powder during pressing and insufficient plasticity of a matrix alloy.

Cold press molding is generally adopted abroad, such as pressureless sintering (sintering in a hydrogen mesh belt furnace, an ammonia decomposition mesh belt furnace and a vacuum furnace), but metal powder used by the matrix alloy is required to be ultrafine powder (the granularity is less than or equal to 10 microns), so that the cold-pressed matrix alloy blank can be ensured to have high sintering reaction activity, the sintering temperature is reduced, the burning loss degree of diamond is reduced, the density of the matrix alloy required by a diamond tool is achieved, the strength, the wear resistance and the holding force of diamond particles of the matrix are ensured, and the superfine alloy powder is very high in price and is not beneficial to development.

Disclosure of Invention

The invention aims to provide a high-pressure cold press molding process of diamond wire saw beads, wherein bead blank is loaded into a high-pressure split combined pressing die, the high-pressure split combined pressing die is provided with a plurality of die splits, and the die splits can be combined to form a die main body.

In order to achieve the purpose, the invention adopts the following technical scheme:

a high-cold press molding process for diamond wire saw beads comprises the following steps:

(1) adding lubricant and matrix alloy powder, mixing and stirring, adding diamond, and continuously mixing and stirring to prepare matrix powder;

(2) placing the prepared carcass powder and the iron core in an automatic press for prepressing and molding to form an integrally molded primary blank;

(3) putting the primary blank into a primary pressing die for pre-pressing and forming, maintaining the pressure to obtain the bead blank with the iron core, and precooling the pressure to 250 plus 500kg/cm²；

(4) Loading a blank of the string beads with the iron core into a split type combined pressing die, and performing high-pressure cold pressing molding on the high-pressure split type combined die by a hydraulic machine; the hydraulic press pressure is set as: 10000-15000kg/cm²Maintaining the pressure; this split type assembling die of high pressure includes: the die comprises a die split body, an upper pressure head, a lower pressure head and a die frame; a plurality of the die split bodies are adjacently and sequentially combined to form a die main body; the die split bodies are provided with a plurality of split gaps, and the split gaps between the die split bodies at adjacent positions are combined to form a die cavity for placing the bead blank; the upper end of the bead blank is contacted with the upper pressure head, and the lower end of the bead blank is contacted with the lower pressure head; two sides of the die main body are arranged in the die frame in an adjustable and elastic manner;

(5) ejecting the bead tire body from the split combined pressing mold, and separating to obtain a diamond bead blank;

(6) and sintering the blank of the diamond bead string to obtain the diamond wire saw bead string.

Further, in the step (1), the raw materials of the carcass powder include: 35-40% of diamond, 59-64% of matrix alloy powder and 0.5-1% of lubricant.

More specifically, in the step (1), the matrix alloy powder includes: 50-65% of Cu-Sn15, 10-15% of electrolytic Cu powder, 10-15% of carbonyl Ni powder, 1-3% of Sn powder, 7-12% of WC powder and 1-3% of Mo powder.

Further, the granularity ratio of the diamond is as follows:

35-40 meshes: 8 to 12 percent;

40-45 meshes: 50-60 percent;

45-50 meshes: 25 to 35 percent;

50-60 meshes: 3 to 7 percent.

In a further aspect, in step (1), the density of the carcass powder is 8.00-8.50g/cm³。

Further, in the step (6), the sintering manner is vacuum sintering, which specifically includes: heating to room temperature when the vacuum degree is 1Pa, heating to 300 deg.C from room temperature at a heating rate of 100 deg.C/hr, maintaining at 300 deg.C for 0.5-1.0 hr, and removing the residual lubricant; then heating from 300 ℃ to 950 ℃, heating at a speed of 250 ℃/h and a vacuum degree of less than 1Pa, keeping the temperature of 950 ℃ for 1-1.5 h, keeping vacuum and naturally cooling to room temperature, and discharging.

Furthermore, in the step (6), the sintering mode is vacuum pressure integrated sintering, and the specific steps are as follows: firstly, the furnace body is vacuumized to 1Pa, residual gas in the furnace is removed for 0.5 to 1.0 hour, then hydrogen is added to 500Pa, the lubricant in the blank is removed, metal powder is reduced, the temperature is kept at 300 ℃ for 0.5 to 1.0 hour, and the residual lubricant is removed;

vacuum sintering at 300-950 deg.C with vacuum degree less than 1Pa, heating rate of 250 deg.C/hr, vacuum sintering at 950 deg.C for 0.5-1.0 hr, adding argon gas at 950 deg.C under 6MPa, maintaining for 0.5-1.0 hr, cooling to room temperature, and discharging.

Further, the high-pressure split combined mold further comprises: a horizontal mode locker; the horizontal mold locker is arranged on the mold frame, and a telescopic pressing end is arranged in the accommodating groove; the telescopic pressing end is connected to one side of the die main body and used for pressing the die main body to the die frame.

Further, the horizontal mould locker is a mould locking hydraulic machine, and the pressure of the horizontal mould locker is not lower than 20 tons/cm²。

In a further aspect, the high-pressure split combined die is fed into and pushed out of the die frame through a horizontal telescopic driver.

The invention has the beneficial effects that:

this cold high pressure forming technology, through the split type combination cold pressing die of unique design, realized that split type assembling die has high mode locking pressure when the high pressure of colding pressing, split type assembling die side pressure release back when colding pressing matrix blank demolding, the very big reduction of frictional force of diamond string of beads matrix and mould cavity has reduced pressure and the degree of wear of die cavity when diamond string of beads matrix demolding, has improved the life of mould greatly.

Drawings

FIG. 1 is a comparison of the present invention (top) and prior art (bottom) prior to sintering;

FIG. 2 is a SEM image of 100 μ size mark of the vacuum sintered sample of example 1;

FIG. 3 is a SEM image of a 100 μ size scale obtained by vacuum pressure sintering in example 2;

FIG. 4 is a 40 μ -size SEM photograph of example 1 during vacuum sintering;

FIG. 5 is a 40 μ -size SEM photograph of the vacuum pressure sintering of example 2;

FIG. 6 is a schematic view of the split part of the mold disassembled;

FIG. 7 is a cross-sectional view of the mold body;

FIG. 8 is a schematic view of the horizontal telescopic actuator before the split mold is placed into the mold frame;

FIG. 9 is a schematic view of the horizontal telescopic driver being used to place the mold split into the mold frame and then to merge the mold split into the mold body;

FIG. 10 is a schematic illustration of a hydraulic press pressing a high pressure split die;

wherein:

a high-pressure split combined die 001 and a hydraulic press 002;

the device comprises a mould main body 1, an upper pressure head 2, a lower pressure head 3, a mould frame 4, a mould cavity 5, a matrix powder 6, an iron core 7, a bead matrix 8, a horizontal mould locker 9 and a horizontal telescopic driver 10;

a mold split 11 and a split notch 12; telescoping hold down end 91.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

A high-cold press molding process for diamond wire saw beads comprises the following steps:

(1) adding lubricant and matrix alloy powder, mixing and stirring, adding diamond, and continuously mixing and stirring to prepare matrix powder;

the matrix powder does not need to be prepared into particles, and only needs to be formed into powder, because the shape of the iron core wrapped by the matrix powder can be pressed by high pressure in the following pressing process, the core can be formed in a split combined pressing die;

(2) placing the prepared carcass powder and the iron core in an automatic press for prepressing and molding to form an integrally molded primary blank;

the step is used for forming a preliminary integrated structure of the matrix powder and the iron core, so that the matrix powder and the iron core are connected into a whole;

(3) putting the primary blank into a primary pressing die for pre-pressing and forming, maintaining the pressure to obtain the bead blank with the iron core, and precooling the pressure to 250 plus 500kg/cm²；

The initial pressing die is a known die, and is pressed by lower pressure, so that limitation is not needed;

(4) loading a blank of the string beads with the iron core into a split type combined pressing die, and performing high-pressure cold pressing molding on the high-pressure split type combined die by a hydraulic machine; the hydraulic press pressure is set as: 10000-15000kg/cm²Setting the pressure maintaining time to be 1-2 minutes; this split type assembling die of high pressure includes: the die comprises a die split body, an upper pressure head, a lower pressure head and a die frame; a plurality of the die split bodies are adjacently and sequentially combined to form a die main body; the die split bodies are provided with a plurality of split gaps, and the split gaps between the die split bodies at adjacent positions are combined to form a die cavity for placing the bead blank; the upper end of the bead blank is contacted with the upper pressure head, and the lower end of the bead blank is contacted with the lower pressure head; two sides of the die main body are arranged in the die frame in an adjustable and elastic manner;

(5) loading the split combined pressing die into a die stripping device, ejecting the bead string matrix from the split combined pressing die, and separating to obtain a diamond bead string blank;

(6) and sintering the blank of the diamond bead string to obtain the diamond wire saw bead string.

This cold high pressure forming technology, through the split type combination cold pressing die of unique design, realized that split type assembling die has high mode locking pressure when the high pressure of colding pressing, split type assembling die side pressure release back when colding pressing matrix blank demolding, the very big reduction of frictional force of diamond string of beads matrix and mould cavity has reduced pressure and the degree of wear of die cavity when diamond string of beads matrix demolding, has improved the life of mould greatly.

In the step (4), all the separated die split bodies are combined and directly installed in the die frame, and the die split bodies are limited and fixed by the inner wall of the die frame, so that split gaps between the die split bodies at adjacent positions form a die cavity; a lower pressure head is arranged at the lower part of the die cavity, and the bead blank is placed into the lower pressure head; at 10000-²Under the high-pressure environment, when the bead blank inside is positively pressed downwards in the die cavity, the material can be opened towards the two sides of the die cavity in a limited space so as to open the split notches as far as possible; in order to prevent the blank of the bead string from easily opening the split notches to disperse the pressure of the positive pressure when the blank of the bead string is subjected to the positive pressure, the split bodies of the dies are limited in the die frame, and the split bodies of the dies are limited by the inner wall, so that the problem of pressure dispersion does not exist; meanwhile, when the split combined pressing die is adopted, after high-pressure pressing is acceptable, subsequent demolding is convenient, and because the connecting force formed between the split dies after pressing is small, after the die main body is led out, the split dies can be separated by only small mechanical force, so that the bead blank with the split notches can be taken out, and the die cannot be abraded; and the pressure of the high-cold press molding is 40 times greater than that of the pre-pressing. Therefore, the compactness of the blank is already large, and the surface of the bead blank is in metal luster.

Further, in the step (1), the raw materials of the carcass powder include: 35-40% of diamond, 59-64% of matrix alloy powder and 0.5-1% of lubricant.

The diamond matrix and the matrix alloy powder are pressed by high pressure, and the pressure of the pressed blank reaches more than or equal to 10000kg/cm²And the pressure is more than 20 times larger than the traditional forming pressure. The metal powder particles with certain ductility such as nickel, iron, tin and the like in the alloy powder and the prealloy powder particles are generated under high pressureThe cold welding phenomenon causes the diamond matrix alloy to have high density, the gaps among alloy powder particles are very small, the density of the high-pressure-cooled matrix alloy blank reaches more than 90% of the theoretical density, the surface of the blank has metal luster, and the blank has high strength and is not easy to break as shown in the upper row position of figure 1; whereas the prior art blank is in the lower row position as shown in fig. 2, it clearly has no gloss.

More specifically, in the step (1), the matrix alloy powder includes: 50-65% of Cu-Sn15, 10-15% of electrolytic Cu powder, 10-15% of carbonyl Ni powder, 1-3% of Sn powder, 7-12% of WC powder and 1-3% of Mo powder.

Furthermore, electrolytic Cu powder and carbonyl Ni powder, which have ductility simple-substance metal powder, have deformation casting and cold welding performance under high pressure, and wrap alloy powder with large rigidity, and gaps in a pressed matrix blank are small, and the density of the blank is close to more than 90% of the theoretical density of the matrix alloy, so that a good foundation is laid for pressureless or hot isostatic pressing sintering.

Further, the granularity ratio of the diamond is as follows:

35-40 meshes: 8 to 12 percent;

40-45 meshes: 50-60 percent;

45-50 meshes: 25 to 35 percent;

50-60 meshes: 3 to 7 percent.

Further, the high-cold-press forming of the diamond matrix is suitable for 300-mesh 500-mesh (30-50 mu m-granularity) prealloy powder and elementary metal powder which are commonly used in China at present, and because the cold brazing phenomenon of the high-pressure forming on the ductile metal powder occurs, partial metal particles of the matrix alloy blank are fused into the alloy before high-temperature sintering, so that the promotion effect on the matrix alloy sintering is achieved, the sintering temperature is reduced, and the high-cold-press forming of the diamond matrix can be completed through pressureless or vacuum sintering. And the foreign pressureless sintering must use ultra-fine alloy powder.

In a further aspect, in step (1), the density of the carcass powder is 8.00-8.50g/cm³。

The density of the matrix powder is excellentIs selected to be 8.45g/cm³。

Further, in the step (6), the sintering manner is vacuum sintering, which specifically includes: heating to room temperature when the vacuum degree is 1Pa, heating to 300 deg.C from room temperature at a heating rate of 100 deg.C/hr, maintaining at 300 deg.C for 0.5-1.0 hr, and removing the residual lubricant; then heating from 300 ℃ to 950 ℃, heating at a speed of 250 ℃/h and a vacuum degree of less than 1Pa, keeping the temperature of 950 ℃ for 1-1.5 h, keeping vacuum and naturally cooling to room temperature, and discharging.

Furthermore, in the step (6), the sintering mode is vacuum pressure integrated sintering, and the specific steps are as follows: firstly, the furnace body is vacuumized to 1Pa, residual gas in the furnace is removed for 0.5 to 1.0 hour, then hydrogen is added to 500Pa, the lubricant in the blank is removed, metal powder is reduced, the temperature is kept at 300 ℃ for 0.5 to 1.0 hour, and the residual lubricant is removed;

vacuum sintering at 300-950 deg.C with vacuum degree less than 1Pa, heating rate of 250 deg.C/hr, vacuum sintering at 950 deg.C for 0.5-1.0 hr, adding argon gas at 950 deg.C under 6MPa, maintaining for 0.5-1.0 hr, cooling to room temperature, and discharging.

Further, the high-pressure split combined mold further comprises: a horizontal mode locker; the horizontal mold locker is arranged on the mold frame, and a telescopic pressing end is arranged in the accommodating groove; the telescopic pressing end is connected to one side of the die main body and used for pressing the die main body to the die frame.

Horizontal mode locker for be fixed in the framed after, use the flexible one side inner wall that compresses tightly the end framed with the mould components of a whole that can function independently merge and compress tightly, provide the horizontally suppress power in side to resist the open effort of string of beads blank, one side in two sides of mould main part is by the flexible end suppression that compresses tightly promptly, and the another side is close to the inner wall in framed, has reduced the load on framed both sides, prevents the load of framed and mould components of a whole that can function independently, improves the life of mould.

After the pressure of the horizontal mold locker is relieved, the bead blank in the mold and the pressure of the mold cavity only basically have the bonding force when the bead blank is contacted with the mold cavity, so that the bead carcass is very little abraded to the mold cavity when the mold is released, the mold cavity cannot be seriously abraded, and the service life of the mold is prolonged.

Further, the horizontal mould locker is a mould locking hydraulic machine, and the pressure of the horizontal mould locker is not lower than 20 tons/cm²。

In a further aspect, the high-pressure split combined die is fed into and pushed out of the die frame through a horizontal telescopic driver.

Further, the horizontal telescopic driver can select a cylinder and other known conventional horizontal transmission devices, the output end of the horizontal telescopic driver can be horizontally connected with the die split bodies, and the die split bodies are pushed into the die frame after the die main bodies are preliminarily combined, so that the die split bodies are combined into the die main bodies; after the pressure of the horizontal mold locker is released, the horizontal telescopic driver can normally take the mold main body out of the mold frame; the effect of preliminarily combining the die main body is achieved.