阅读说明：本技术 一种带凹槽的cbn刀具加工工艺 (Machining process of CBN cutter with groove ) 是由 张小友 韩顺利 于 2021-09-26 设计创作，主要内容包括：本发明公开了一种带凹槽的CBN刀具加工工艺,涉及超硬材料刀具加工技术领域,该工艺包括以下步骤：使用压制模具将CBN粉料压制成带凹槽的毛坯；使用钨钴合金填充毛坯上的凹槽,得到填充毛坯；将填充毛坯组装成高压合成块；将高压合成块在高温高压下合成,得到CBN刀具半成品；最后从高压合成块中取出CBN刀具半成品,并将CBN刀具半成品与硬质合金分离,然后使用磨削工具对CBN刀具半成品进行修整,再经过倒棱并使用钝化毛刷钝化,得到CBN刀具成品。该工艺用于取代现有的激光雕刻开槽方法,在高压合成阶段可直接得到带凹槽的CBN刀具,大幅降低带凹槽CBN刀具的制作成本,有利于推动带凹槽CBN刀具的应用。(The invention discloses a CBN cutter processing technology with a groove, relating to the technical field of superhard material cutter processing, and the technology comprises the following steps: pressing the CBN powder into a blank with a groove by using a pressing die; filling the grooves in the blank with tungsten-cobalt alloy to obtain a filled blank; assembling the filling blanks into a high-pressure synthesis block; synthesizing the high-pressure synthesis block at high temperature and high pressure to obtain a CBN cutter semi-finished product; and finally, taking out the CBN cutter semi-finished product from the high-pressure synthesis block, separating the CBN cutter semi-finished product from the hard alloy, finishing the CBN cutter semi-finished product by using a grinding tool, chamfering and passivating by using a passivating brush to obtain a CBN cutter finished product. The process is used for replacing the existing laser engraving grooving method, the CBN cutter with the groove can be directly obtained in the high-pressure synthesis stage, the manufacturing cost of the CBN cutter with the groove is greatly reduced, and the application of the CBN cutter with the groove is promoted.)

1. A machining process of a CBN cutter with a groove is characterized by comprising the following steps:

(1) pressing the CBN powder into a blank with a groove by using a pressing die;

(2) filling the grooves in the blank with tungsten-cobalt alloy to obtain a filled blank;

(3) assembling the filling blanks into a high-pressure synthesis block;

(4) synthesizing the high-pressure synthesis block at high temperature and high pressure to obtain a CBN cutter semi-finished product;

(5) and taking out the CBN cutter semi-finished product from the high-pressure synthesis block, separating the CBN cutter semi-finished product from the hard alloy, finishing the CBN cutter semi-finished product by using a grinding tool, chamfering and passivating by using a passivating brush to obtain a CBN cutter finished product.

2. The CBN tool machining process with the groove as claimed in claim 1, wherein in the step (1), the pressing mold comprises an upper pressing head, a lower pressing head and a mold barrel, and male molds for pressing the groove are arranged on the upper pressing head and the lower pressing head respectively.

3. The CBN tool machining process with the groove as claimed in claim 1, wherein in the step (3), the high-pressure synthesis block comprises a pressure guide medium, a plug, a titanium plate, a carbon mold and a plurality of filling blanks, the plug, the titanium plate, the carbon plate and the filling blanks are stacked together in an order from outside to inside, the filling blanks are stacked together in an order from top to bottom and separated by the carbon plate, and the side surfaces of the filling blanks are sequentially wrapped by the carbon mold and the pressure guide medium.

4. The CBN cutter machining process with the groove as claimed in claim 1, wherein in the step (4), the synthetic pressure is 6 +/-0.5 GPa, and the synthetic temperature is 1200-1400 ℃.

5. The grooved CBN tool processing method as claimed in claim 1, wherein in the step (5), the dressing is performed by inserting the grooves on the CBN tool blank using the ejector pins and fixing it on the grinding tool.

6. The CBN tool machining process with the groove as claimed in claim 4, wherein the pressure guide medium is pyrophyllite.

7. The machining process of the CBN cutter with the groove as claimed in claim 5, wherein a protrusion is arranged on the ejector pin, and the shape of the protrusion is the same as that of the groove on the semi-finished product of the CBN cutter.

Technical Field

The invention relates to the technical field of superhard material cutter processing, in particular to a CBN cutter processing technology with grooves.

Background

The Cubic Boron Nitride (CBN) superhard cutter plays an increasingly important role in the field of ferrous metal machining in modern manufacturing industry, has obvious advantages of service life, machining quality, machining efficiency and machining cost compared with the traditional hard alloy cutter and ceramic cutter, is developed vigorously in China in recent years, and has a very wide prospect.

Whether CBN cutter can divide into two kinds according to taking the recess, the whole CBN cutter production and processing cost who does not take the recess is low, but there is the fit clearance when dress card is on the cutter arbor, lead to taking place vibrations in high-speed course of working, thereby to the life of cutter with by the processing object production harmful effects, the dress card mode that takes the recess can effectually avoid the dress card clearance, the vibrations that significantly reduce, but because the hardness of whole CBN cutter is high, it is very difficult to process out the recess shape that meets the requirements on the CBN cutter.

The conventional machining method of the CBN cutter at present is to carve a manufactured planar CBN cutter blade by a laser grinding machine after the overall dimension is machined, so that a required groove shape is obtained, and due to the fact that the allowance of the required groove shape is large, high-power laser is required to be used for carving, the machining time is long, the yield is not high, and the integral CBN cutter with the groove is difficult to popularize in the market.

Disclosure of Invention

The invention aims to: the machining process of the CBN cutter with the groove is provided, the CBN cutter with the groove can be directly produced, high-cost grooving processes such as laser engraving can be replaced, and the production cost is greatly reduced.

The technical scheme adopted by the invention is as follows:

a machining process of a CBN cutter with a groove comprises the following steps:

(1) pressing the CBN powder into a blank with a groove by using a pressing die;

(2) filling the grooves in the blank with tungsten-cobalt alloy to obtain a filled blank;

(3) assembling the filling blanks into a high-pressure synthesis block;

(4) synthesizing the high-pressure synthesis block at high temperature and high pressure to obtain a CBN cutter semi-finished product;

(5) and taking out the CBN cutter semi-finished product from the high-pressure synthesis block, separating the CBN cutter semi-finished product from the hard alloy, finishing the CBN cutter semi-finished product by using a grinding tool, chamfering and passivating by using a passivating brush to obtain a CBN cutter finished product.

Preferably, in the step (1), the pressing mold comprises an upper pressing head, a lower pressing head and a mold barrel, and male molds for pressing the grooves are arranged on both the upper pressing head and the lower pressing head.

Preferably, in the step (3), the high-pressure synthesis block includes a pressure guide medium, a plug, a titanium plate, a carbon mold and a plurality of filling blanks, the plug, the titanium plate, the carbon plate and the filling blanks are stacked together in sequence from outside to inside, the plurality of filling blanks are stacked together in sequence from top to bottom and separated by the carbon plate, and the side surfaces of the filling blanks are sequentially wrapped by the carbon mold and the pressure guide medium.

Preferably, in the step (4), the synthesis pressure is 6 +/-0.5 GPa, and the synthesis temperature is 1200-1400 ℃.

Preferably, in the step (5), when dressing is performed, the thimble is used to insert the groove on the CBN tool semi-finished product and fix it on the grinding tool.

Preferably, the pressure guide medium is pyrophyllite.

Preferably, the ejector pin is provided with a bulge, and the shape of the bulge is the same as that of the groove on the CBN cutter semi-finished product.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

(1) according to the invention, the upper pressure head and the lower pressure head with special shapes are adopted to press the CBN powder into a blank with a groove, then hard alloy is filled in the groove to form a combined whole, then a CBN cutter semi-finished product with the groove is obtained through high-temperature high-pressure synthesis, and finally a CBN cutter finished product with the groove can be obtained through grinding, trimming, chamfering and passivation;

(2) in the grinding and finishing process, the ejector pin with the protrusion is adopted to fix the CBN cutter semi-finished product, the consistency of the groove is ensured, the groove and the cutter outline have good concentricity, the problem that the geometric center of the groove and the geometric center of the cutter in the traditional laser engraving process have large deviation is solved, and compared with the traditional process, the yield can be improved by more than 10%;

(3) the hard alloy particles can be easily separated from the grooves due to the difference of contraction speeds of the blank and the hard alloy filling particles after synthesis is finished, and the hard alloy particles are located in the center of the integral assembly structure, almost do not deform after synthesis is finished, and can be reused after surface treatment.

Drawings

Fig. 1 is a perspective view of a press mold.

Fig. 2 is a rear view structural view of a pressing die.

Fig. 3 is a left side view structural view of the pressing die.

Fig. 4 is an assembly view of the pressing die.

Fig. 5 is a cross-sectional view of a blank.

Fig. 6 is a cross-sectional view of a filled blank.

Fig. 7 is a structural diagram of a high-pressure synthesis block.

Fig. 8 is a perspective view of the thimble.

FIG. 9 is a schematic view of the grinding of the upper and lower surfaces of a CBN tool blank.

FIG. 10 is a schematic view of the grinding of the periphery of a CBN tool.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and embodiments, it being understood that the specific embodiments described herein are only for the purpose of explaining the present invention and are not intended to limit the present invention.

Taking a cubic boron nitride superhard cutter named CNGX120712S05020 as an example, the finished product is an 80-degree rhombic blade with the thickness of 7.94mm and the radius of an inscribed circle of 12.7mm, the radius of the fillet of the blade is 1.2mm, the upper surface and the lower surface of the blade are provided with the same groove, the groove is a coupled double-hemisphere type groove which is a curved surface similar to a peanut shell and is formed by communicating a hemisphere with the radius of 2.5mm and a hemisphere with the radius of 4.2mm, and the sectional view refers to fig. 9.

Example 1

Manufacturing a filling blank:

(1) taking a pressing die as shown in figure 1, wherein the pressing die adopts a common carbon die and comprises an upper pressing head, a lower pressing head and a die barrel, male dies for pressing grooves are arranged on the upper pressing head and the lower pressing head, the shape of the top end of each male die is consistent with that of a groove on a tool to be processed and is formed by connecting a hemisphere with the radius of 2.5mm and a hemisphere with the radius of 4.2mm, a die cavity for accommodating the upper pressing head and the lower pressing head is arranged in the middle of the die barrel, the cross section of the die cavity is in the shape of an 80-degree diamond hole with the radius of an inscribed circle of 16.5mm and the radius of a chamfer arc of 2mm, the size of the diamond hole is slightly larger than that of the tool to be manufactured so as to leave processing allowance, the cross sections of the upper pressing head and the lower pressing head are the same as the die cavity, the lower pressing head is placed at the bottom of the die barrel, then a certain amount of Cubic Boron Nitride (CBN) is poured, the powder material is selected from cubic boron nitride particles with the particle size of which is less than 20 microns, then the upper pressing head is inserted into the die barrel from the upper opening of the die cavity, obtaining a pressing die shown in figure 4, and putting the pressing die into a press machine for pressing to obtain a blank with a groove, wherein the structure of the blank is shown in figure 5;

(2) taking 2 pieces of tungsten-cobalt alloy with the model number of YG8, processing the tungsten-cobalt alloy into the shape of a male die, and then putting the tungsten-cobalt alloy into a groove on a blank to fill the groove with the tungsten-cobalt alloy to obtain a filling blank shown in figure 6;

example 2

Synthesizing a CBN cutter under the conditions of 1300 ℃ and 6 GPa:

(1) assembling the filling blank, the pyrophyllite powder, the plug, the titanium sheet, the carbon sheet and the carbon mold shown in fig. 6 into a high-pressure synthesis block, wherein the plug, the titanium sheet, the carbon sheet and the filling blank are stacked together in sequence from outside to inside, 3 filling blanks are stacked together in sequence from top to bottom and separated by using 2 carbon sheets, and the side surface of the filling blank is sequentially wrapped by the carbon mold and the pyrophyllite powder layer, as shown in fig. 7;

(2) and (3) putting the assembled high-pressure synthetic block into a cubic press, pressurizing to 6GPa at 1300 ℃, keeping the pressure for 15 minutes, cooling, taking out the pressurized high-pressure synthetic block, disassembling and continuously cooling, wherein the tungsten-cobalt alloy block is separated from the inner wall of the groove due to different shrinkage rates of the tungsten-cobalt alloy and the cubic boron nitride in the cooling process, and the tungsten-cobalt alloy block can be directly poured out to obtain a semi-finished product of the CBN cutter.

Example 3

Synthesizing a CBN cutter under the conditions of 1200 ℃ and 6.5GPa under high pressure:

(1) assembling the filling blank, the pyrophyllite powder, the plug, the titanium sheet, the carbon sheet and the carbon mold shown in fig. 6 into a high-pressure synthesis block, wherein the plug, the titanium sheet, the carbon sheet and the filling blank are stacked together in sequence from outside to inside, 3 filling blanks are stacked together in sequence from top to bottom and separated by using 2 carbon sheets, and the side surface of the filling blank is sequentially wrapped by the carbon mold and the pyrophyllite powder layer, as shown in fig. 7;

(2) and (3) putting the assembled high-pressure synthetic block into a cubic press, pressurizing to 6.5GPa at 1200 ℃, keeping for 15 minutes, cooling to below 150 ℃, taking out the pressurized high-pressure synthetic block, disassembling and continuously cooling, wherein the tungsten-cobalt alloy block is separated from the inner wall of the groove due to different shrinkage rates of the tungsten-cobalt alloy and the cubic boron nitride in the cooling process, so that the tungsten-cobalt alloy block can be directly poured out to obtain a semi-finished product of the CBN cutter.

Example 4

Synthesizing a CBN cutter under the conditions of 1400 ℃ and 5.5 GPa:

(1) assembling the filling blank, the pyrophyllite powder, the plug, the titanium sheet, the carbon sheet and the carbon mold shown in fig. 6 into a high-pressure synthesis block, wherein the plug, the titanium sheet, the carbon sheet and the filling blank are stacked together in sequence from outside to inside, 3 filling blanks are stacked together in sequence from top to bottom and separated by using 2 carbon sheets, and the side surface of the filling blank is sequentially wrapped by the carbon mold and the pyrophyllite powder layer, as shown in fig. 7;

(2) and putting the assembled high-pressure synthetic block into a cubic press, pressurizing to 5.5GPa at 1400 ℃, keeping for 15 minutes, cooling, taking out the pressurized high-pressure synthetic block, disassembling and continuously cooling, wherein the tungsten-cobalt alloy block is separated from the inner wall of the groove due to different shrinkage rates of the tungsten-cobalt alloy and the cubic boron nitride in the cooling process, so that the tungsten-cobalt alloy block can be directly poured out to obtain a semi-finished product of the CBN cutter.

Example 5

And (3) carrying out finish machining on the CBN cutter semi-finished product:

(1) taking the CBN tool semi-finished product obtained in any embodiment of the embodiments 2-4, carrying out sand blasting cleaning on the groove on a sand blasting machine, then carrying out equal grinding on two planes of the CBN tool semi-finished product on a surface grinding machine, removing the allowance to about 8.1mm, then carrying out grinding plane treatment until the thickness is 7.94+0.03mm, as shown in figure 9, then carrying out equal grinding on four side edges on a surface grinding machine, removing the allowance, and controlling the size of a rhombic inscribed circle to be 12.95+0.05 mm;

(2) the groove of the CBN cutter semi-finished product is clamped by a thimble shown in figure 8 on a peripheral mill, the peripheral allowance is equally removed by taking the groove as the center, the thimble is provided with a bulge, the shape of the bulge is the same as that of the groove on the CBN cutter semi-finished product, the CBN cutter semi-finished product can be prevented from shifting in the grinding and trimming process, finally, a 80-degree diamond blade with the diamond inner tangent circle of 12.7 +/-0.025 mm and the chamfer radius of 1.2mm is ground, as shown in figure 10, the blade is turned into a cutting edge with the angle of 0.5mm +/-20 degrees on a universal tool mill, and finally, a passivation brush with the angle of 140# is used on a passivation machine for passivation, so that the CNGX120712S05020 cutter with a special groove shape is obtained.

The tungsten-cobalt alloy block has high hardness, basically does not deform after being used, can be reused after ball milling and thorn removal, and saves cost.

According to statistics, compared with the traditional laser engraving grooving process, after the process is adopted, a high-cost laser engraving mode is not needed for grooving, the comprehensive cost is reduced by about 20%, and the geometric center of the groove machined by laser engraving and the geometric center of the cutter have large deviation, but the process does not have the problem, so that the overall yield is improved by about 10%.

The above embodiment is used for processing a conventional cutter named CNGX120712S05020, and the shapes of the upper pressure head, the lower pressure head, the carbon mold and the thimble are changed correspondingly to realize cutters with different groove types and different shapes.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.