阅读说明：本技术 一种用于钻铣加工的平界面多晶金刚石复合材料 (Flat interface polycrystalline diamond composite material for drilling and milling ) 是由 贺端威 杨缤维 于 2019-10-18 设计创作，主要内容包括：本发明公开了一种用于钻铣加工的平界面多晶金刚石复合材料,包括金刚石层和硬质合金基体,所述金刚石层厚度为2mm～10mm,金刚石层与硬质合金基体接触面为平面接触,晶金刚石层与硬质合金基体的接触界面平整度达0.001mm～0.003mm。本发明提供的平界面多晶金刚石复合材料技术,可以有效消除界面处的应力集中,显著提高材料的均匀性,避免在界面处的多晶金刚石层中形成钴的富集区,以及在金刚石复合片的高温高压烧结过程中发生金刚石晶粒的异常长大等缺陷；大量的实验及应用实例表明,用于钻铣加工的平界面多晶金刚石复合材料,在刀具成型效率、刃口精度、使用寿命等方面,相比于传统异形界面多晶金刚石复合材料,均可提高30％以上。(The invention discloses a plane interface polycrystalline diamond composite material for drilling and milling, which comprises a diamond layer and a hard alloy matrix, wherein the thickness of the diamond layer is 2-10 mm, the contact surface of the diamond layer and the hard alloy matrix is in plane contact, and the flatness of the contact interface of the diamond layer and the hard alloy matrix reaches 0.001-0.003 mm. The flat interface polycrystalline diamond composite material technology provided by the invention can effectively eliminate stress concentration at the interface, obviously improve the uniformity of the material, and avoid the defects of cobalt enrichment area formed in the polycrystalline diamond layer at the interface, abnormal growth of diamond grains and the like in the high-temperature high-pressure sintering process of the diamond composite sheet; a large number of experiments and application examples show that the flat interface polycrystalline diamond composite material for drilling and milling can be improved by more than 30% in the aspects of cutter forming efficiency, cutting edge precision, service life and the like compared with the traditional special-shaped interface polycrystalline diamond composite material.)

1. A polycrystalline diamond composite material with a flat interface for drilling and milling processing comprises a diamond layer and a hard alloy matrix, and is characterized in that the thickness of the diamond layer is 2-10 mm, the bonding surface of the diamond layer and the hard alloy matrix is a flat interface, and the flatness of the bonding interface of the diamond layer and the hard alloy matrix is less than or equal to 3 thousandths; flatness is the diameter of the composite, and includes the undulations and slopes of the bonding interface.

2. The method of preparing a flat interface polycrystalline diamond composite material for use in drilling and milling as claimed in claim 1, comprising the steps of:

placing the flat-interface diamond powder block and the flat-interface hard alloy matrix block in a cubic press, and synthesizing under the conditions of high temperature and high pressure; the synthesis pressure is 5.0 GPa-8.0 GPa, the synthesis temperature is 1400 ℃ to 1700 ℃, and the heat preservation and pressure maintaining time is 1min to 100 min; after the heat preservation and the pressure maintenance are finished, reducing the pressure and the temperature to finally obtain the flat interface polycrystalline diamond composite material; in the processes of pressurizing and heating and subsequent heat preservation and pressure maintaining in the cubic press, the pressing pistons in six directions of the cubic press always keep consistent synchronism and centering property.

3. The method for preparing the flat interface polycrystalline diamond composite material for drilling and milling as claimed in claim 2, wherein the synchronicity deviation of pressing pistons in six directions in the pressing process of the cubic press is less than or equal to 0.2mm, and the centering deviation is less than or equal to 0.2 mm.

4. The method for preparing the flat interface polycrystalline diamond composite material for drilling and milling according to claim 2, wherein after the heat preservation and pressure maintenance are finished, the temperature is reduced at a speed of 50 ℃/min-500 ℃/min, and the pressure is reduced at a speed of 0.3 GPa/min-3 GPa/min.

5. The cubic press for synthesizing the polycrystalline diamond composite material is characterized by comprising an oil cylinder (1), a cylinder cover (2), a piston (3), a pressure equalizing pad (4), a top hammer (5), a displacement sensor assembly (6) and a laser centering assembly (7), wherein the oil cylinder (1), the cylinder cover (2), the piston (3), the pressure equalizing pad (4) and the top hammer (5) are sequentially connected, the displacement sensor assembly (6) is used for detecting displacement information of the piston (3) relative to the oil cylinder (2), sending the detected displacement information to a control center, and controlling the oil volume of hydraulic oil of the oil cylinder through the control center; the laser centering assembly (7) is arranged on the end face of the cylinder cover (2) and is used for detecting the centering performance of the piston in the front-back direction, the left-right direction and the up-down direction; the cubic press is used in the production method according to any one of claims 2 to 5.

6. The cubic press for synthesizing polycrystalline diamond composite material according to claim 5, wherein the piston (3) is provided with a through hole I (8), the oil cylinder (1) is provided with a through hole II (9), and the axial lines of the through hole I (8), the through hole II (9) and the piston (3) are coincided; the displacement sensor assembly (6) comprises a sleeve (61), a sensor (62), a detection rod (63) and a magnetic ring (64); the sleeve (61) comprises a movable sleeve (611) and a fixed sleeve (612), one end of the fixed sleeve (612) is fixed on the end face of the outer side of the oil cylinder (1) in a sealing mode, the other end of the fixed sleeve penetrates through the through hole II (9) and then extends into the through hole I (8), one end of the movable sleeve (611) is fixed between the contact surfaces of the pressure equalizing pad (4) and the piston (3) in a sealing mode, the other end of the movable sleeve extends into the through hole I (8) and is sleeved outside the fixed sleeve (612); the movable sleeve (611) moves along with the piston (3), and the outer wall of the fixed sleeve (612) is in sealing contact with the inner wall of the movable sleeve (611) through a sealing ring cover (613);

the pressure equalizing device is characterized in that an installation groove (10) is formed in the end face, in contact with the piston (3), of the pressure equalizing pad (4), a sensor (62) is arranged in the installation groove (10), one end of the detection rod (63) is connected with the sensor (62), the other end of the detection rod extends into the fixed sleeve (612) through the movable sleeve (611), and a magnetic ring (64) matched with the detection rod (63) is arranged in the fixed sleeve (612).

7. The cubic press for synthesizing polycrystalline diamond composite material according to claim 6, wherein one end of the movable sleeve (611) is extended outward to form an annular pressing sheet (65), the end face of the piston (3) facing the pressure equalizing pad (4) is provided with a sealing hole (11), the sealing hole (11) and the through hole I (8) are coaxial, the inner diameter of the sealing hole (11) is larger than the inner diameter of the through hole I (8) and larger than the inner diameter of the mounting groove (10), and the joint of the sealing hole (11) and the through hole I (8) forms a step; a sealing ring (12) is arranged in the sealing hole (11), the sealing ring (12) is tightly pressed between the lower surface of the annular pressing sheet (65) and the end surface of the step, and the upper surface of the annular pressing sheet (65) is in contact with the lower end surface of the pressure equalizing pad (4); and the other end of the fixed sleeve (612) extends out of the through hole II (9) and is provided with an external thread, and the external thread is screwed in the thread section of the fixed sleeve (612) through a sealing nut (12) for fixation.

8. The cubic press for synthesizing polycrystalline diamond composite according to claim 6, wherein the outer surface of the tube section of the movable sleeve (611) in the through hole I (8) is provided with corrugated sheets (66), and the corrugated sheets (66) are distributed in a wave shape along the circumference of the movable sleeve (611); the corrugated peaks of the corrugated sheet (66) are in contact with the inner wall of the through hole I (8).

9. The cubic press for synthesizing polycrystalline diamond composite according to claim 5, wherein said laser centering assembly (7) comprises a mounting ring (71), an adjusting ring (72), a positioning ring (73) and a laser (74), said mounting ring (71) is detachably fixed on the end surface of the cylinder head (2), and a fixing ring (75) coaxially extending upward is provided on the end surface of the mounting ring (71) away from the cylinder head (2); the adjusting ring sleeve (72) is sleeved outside the fixing ring (75), and the inner wall of the adjusting ring sleeve (72) is in rolling contact with the outer wall of the fixing ring (75) through balls; the positioning ring sleeve (73) comprises a vertical pipe section and a horizontal pressing plate section and is of a T-shaped structure, the vertical pipe section is sleeved in the fixing ring (75), the outer wall of the vertical pipe section is connected with the inner wall of the fixing ring (75) through threads, and the horizontal pressing plate section is used for pressing the adjusting ring sleeve (72); the outer wall of the piston (3) is in clearance fit with the inner wall of the mounting ring sleeve (71) and the inner wall of the positioning ring sleeve (73); the laser (74) is arranged in the adjusting ring sleeve (72), and the end face of the free end of the adjusting ring sleeve (72) is provided with a laser emitting/receiving hole (76).

10. The cubic press for synthesizing polycrystalline diamond composite according to claim 9, wherein the end face of said mounting ring (71) is further provided with angle rulers (77) continuously distributed along the circumferential direction, and the bottom side wall of said adjusting ring (72) is provided with an indicating key (78) adapted to the angle rulers (77).

Technical Field

The invention relates to the technical field of superhard materials, in particular to a flat interface polycrystalline diamond composite material for drilling and milling.

Background

Polycrystalline Diamond composite materials (also known as Diamond compacts, having english name of polycrystalline Diamond compact, often abbreviated as PCD or PDC) are widely used for manufacturing superhard cutters or drill teeth for oil and gas drills. Compared with the traditional cutter and drill tooth made of hard alloy, tool steel, ceramic and the like, the cutter and drill tooth made of the polycrystalline diamond composite material have the advantages of high speed, high efficiency, energy conservation, environmental protection, high wear resistance, long service life and the like. The polycrystalline diamond composite material is formed by sintering and compounding a polycrystalline diamond layer and a hard alloy (WC-Co alloy) substrate at high temperature and high pressure. Diamond compacts for use in the manufacture of cutting tools typically have a polycrystalline diamond layer thickness of no more than 1mm, whilst polycrystalline diamond composites for use in the manufacture of teeth or milling and drilling tools typically have a diamond layer thickness of greater than 2 mm. The diamond composite sheet is applied to oil and gas drilling or the drilling and milling of metal and inorganic non-metal materials (such as aluminum alloy, glass, ceramic, carbon fiber composite materials and the like), and in the drilling and milling process, the polycrystalline diamond working layer needs to bear high shear stress, and the distance between the cutting edge of the polycrystalline diamond working layer and the interface is usually more than 2mm, so that the shear stress moment at the interface is rapidly increased, and the delamination of diamond and a hard alloy substrate at the interface is easily caused, therefore, the interface of the polycrystalline diamond composite sheet is usually an uneven special-shaped interface (as shown in figures 1 and 2) to increase the bonding force between the polycrystalline diamond layer and the hard alloy substrate and prevent the delamination.

However, with the continuous improvement of the requirements for the performance of the diamond compact, the polycrystalline diamond composite material with the irregular interface has the following disadvantages in the processes of cutting edge forming and drilling and milling: 1) uneven special-shaped interfaces can cause the unevenness of materials at the interfaces, such as the formation of a cobalt enrichment area in a polycrystalline diamond layer at the interfaces and the abnormal growth of diamond grains in the high-temperature and high-pressure sintering process of a diamond compact, and the like, and the unevenness of the materials can seriously affect the processing and forming efficiency and precision of a drilling and milling cutter; 2) the uneven special-shaped interface can generate stress concentration at the groove or the protrusion, so that microcracks are generated at the stress concentration of the interface in the use process, and finally the material fails.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the invention provides a flat interface polycrystalline diamond composite material for drilling and milling, which solves the problems that the processing and forming of a drilling and milling cutter are influenced by the nonuniformity of the polycrystalline diamond composite material prepared by a conventional sintering method, and stress concentration is easy to crack in the using process.

The invention is realized by the following technical scheme:

a polycrystalline diamond composite material with a flat interface for drilling and milling comprises a diamond layer and a hard alloy matrix, wherein the thickness of the diamond layer is 2-10 mm, the bonding surface of the diamond layer and the hard alloy matrix is a flat interface, and the flatness of the bonding interface of the diamond layer and the hard alloy matrix is less than or equal to 3 thousandths; flatness is the diameter of the composite, and includes the undulations and slopes of the bonding interface. The flatness referred to in the present invention mainly refers to the waviness and the gradient of the bonding interface, and if the horizontal plane of the bonding interface is taken as a reference, the flatness | the height of an arbitrary detection position — the horizontal plane of the bonding interface |.

The flat interface polycrystalline diamond composite material technology provided by the invention can effectively eliminate stress concentration at the interface, obviously improve the uniformity of the material, and avoid the defects of cobalt enrichment area formed in the polycrystalline diamond layer at the interface, abnormal growth of diamond grains and the like in the high-temperature high-pressure sintering process of the diamond composite sheet; a large number of experiments and application examples show that the flat interface polycrystalline diamond composite material for drilling and milling can be improved by more than 30% in the aspects of cutter forming efficiency, cutting edge precision, service life and the like compared with the traditional special-shaped interface polycrystalline diamond composite material; in addition, the polycrystalline diamond composite material has good interface bonding performance and higher impact toughness, the interface bonding strength of the polycrystalline diamond composite material is superior to that of a diamond composite sheet with a special-shaped interface, and the impact toughness can be improved by more than 30 percent.

A preparation method of a flat interface polycrystalline diamond composite material for drilling and milling comprises the following steps:

placing the flat-interface diamond powder block and the flat-interface hard alloy matrix block in a cubic press, and synthesizing under the conditions of high temperature and high pressure; the synthesis pressure is 5.0 GPa-8.0 GPa, the synthesis temperature is 1400 ℃ to 1700 ℃, and the heat preservation and pressure maintaining time is 1min to 100 min; after the heat preservation and the pressure maintenance are finished, reducing the pressure and the temperature to finally obtain the flat interface polycrystalline diamond composite material; in the processes of pressurizing and heating and subsequent heat preservation and pressure maintaining in the cubic press, the pressing pistons in six directions of the cubic press always keep consistent synchronism and centering property.

Furthermore, the synchronicity deviation of the top pressing pistons in six directions in the pressing process of the cubic press is less than or equal to 0.2mm, and the centering deviation is less than or equal to 0.2 mm.

Further, after the heat preservation and pressure maintenance are finished, the temperature is reduced at the speed of 50 ℃/min to 500 ℃/min, and the pressure is reduced at the speed of 0.3GPa/min to 3 GPa/min.

The cubic apparatus press for synthesizing the polycrystalline diamond composite material comprises an oil cylinder, a cylinder cover, a piston, a pressure equalizing pad and a top hammer, which are sequentially connected, and further comprises a displacement sensor assembly and a laser centering assembly, wherein the displacement sensor assembly is used for detecting displacement information of the piston relative to the oil cylinder and sending the detected displacement information to a control center, and the control center controls the oil mass of hydraulic oil of the oil cylinder to realize that the displacement deviation of each pressure cylinder is less than 0.2 mm; the laser centering assembly is arranged on the end face of the cylinder cover and used for detecting the centering performance of the piston in front and back, left and right, and up and down directions; the cubic press is used in the preparation method of the polycrystalline diamond composite material.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a schematic view of the overall structure of an oil cylinder and a piston according to the present invention;

FIG. 2 is a schematic perspective view of the bushing of the present invention;

FIG. 3 is a schematic view of the axial cross-section of the inventive sleeve;

FIG. 4 is a schematic view of the radial cross-section of the active cannula of the present invention;

FIG. 5 is an exploded view of the laser centering assembly of the present invention;

FIG. 6 is a schematic view of a radial cross-sectional structure of a laser centering assembly of the present invention.

Reference numbers and corresponding part names in the drawings: 1-oil cylinder, 2-cylinder cover, 3-piston, 4-pressure equalizing pad and 5-top hammer; 6-displacement sensor component, 61-sleeve, 62-sensor, 63-detection rod, 64-magnetic ring, 65-annular pressing sheet, and 66-corrugated sheet; 7-laser centering component, 71-mounting ring, 72-adjusting ring, 73-positioning ring, 74-laser, 75-fixing ring, 76-laser emitting/receiving hole, 77-angle ruler, 78-indicating key; 8-through hole I, 9-through hole II, 10-mounting groove, 11-sealing hole and 12-sealing ring.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.