CN114807907A

CN114807907A - MPCVD carrier and method for depositing diamond coating on surface of cutter

Info

Publication number: CN114807907A
Application number: CN202210478201.7A
Authority: CN
Inventors: 王晓飞; 邬苏东; 任富增; 赵予生
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology
Priority date: 2022-05-05
Filing date: 2022-05-05
Publication date: 2022-07-29

Abstract

The application relates to the technical field of microwave plasma chemical vapor deposition, in particular to an MPCVD carrier and a method for depositing a diamond coating on the surface of a cutter. The MPCVD carrier includes that base station and end to end's metal enclose the fender, and the surface of base station has the region of placing, and the metal encloses the fender and sets up in the surface of base station and enclose to locate around placing the region. The application provides a MPCVD carrier is used for when tool surface deposit diamond coating, be favorable to making tool blade department grow out the high-quality diamond coating that adhesive force is strong, thickness is even and continuous fine and close, not only can strengthen the intensity and the wearability of tool blade, delay the wearing and tearing inefficacy of cutting blade, improve tool life-span and cutting efficiency, can also improve the cutting area state of tool, promote the robustness of tool and the controllability of work piece processing surface quality, and guarantee the processing surface quality and the precision of tool, make the comprehensive properties of cutting tool obtain promoting.

Description

MPCVD carrier and method for depositing diamond coating on surface of cutter

Technical Field

The application relates to the technical field of microwave plasma chemical vapor deposition, in particular to an MPCVD carrier and a method for depositing a diamond coating on the surface of a cutter.

Background

High hardness (meaning hardness values in excess of 50HRC) materials are typically difficult to machine materials. When a high hardness material is cut with a tool, it is difficult to increase the cutting speed because the high hardness material has high deformation resistance and increases the wear of the tool, and therefore, the cutting tool is required to have excellent wear resistance and the like. The quality of the cutting tool directly affects the processing precision, quality and efficiency of the workpiece material; the cutting integrity and wear failure morphology of the tool during cutting also directly affects the machined surface quality and dimensional accuracy of the tool. Tool coating technology has now become a key technology to improve tool performance.

The diamond film becomes an excellent wear-resistant coating cutter material due to the advantages of ultrahigh hardness, low friction coefficient, high chemical stability and the like of the diamond, and is applied to high-efficiency and high-precision processing of high-hardness materials.

Since the MPCVD (microwave plasma chemical vapor deposition) method has the advantages of plasma energy concentration and stable process, the MPCVD method is generally used to deposit diamond coating on the surface of the cutting tool. However, when the tool is diamond-coated by the MPCVD method, the diamond coating which has strong adhesion, uniform thickness and is continuous and compact is difficult to deposit at the cutting edge of the tool, so that the diamond-coated tool is worn and damaged by bearing the coupling action of strong mechanical load and thermal load in the process of high-efficiency processing, the service life of the tool is short, and the processing cost is high.

Disclosure of Invention

The application aims to provide an MPCVD carrier and a method for depositing a diamond coating on the surface of a cutter, which aim to solve the technical problem that the existing cutter cannot effectively deposit a high-quality diamond coating which is strong in adhesive force, uniform in thickness, continuous and compact at a cutting edge.

The first aspect of the application provides an MPCVD carrier, which comprises a base station and metal enclosing barriers connected end to end; the surface of the base platform is provided with a placing area; the metal enclosure is arranged on the surface of the base station and around the placement area.

This application has the base station of placing the region through the setting and sets up in the base station surface and enclose to locate and place regional metal all around and enclose the fender and constitute MPCVD carrier, when it is used for tool surface deposit diamond coating, be favorable to making tool blade department grow out the adhesive force strong, even and continuous fine and close high-quality diamond coating of thickness, not only can strengthen the intensity and the stand wear and tear performance of tool cutting edge, it became invalid to delay the wearing and tearing of cutting edge, improve tool life-span and cutting efficiency, can also improve the cutting area state of tool, promote the robustness of tool and the controllability of work piece processing surface quality, and guarantee the processing surface quality and the precision of tool, make the comprehensive properties of cutting tool obtain promoting.

In a second aspect of the present application, there is provided a method of depositing a diamond coating on a tool surface, comprising placing a tool on a placement region of an MPCVD carrier as provided in the first aspect above, and depositing a diamond coating on the tool surface.

Wherein the height of the metal enclosure is 0-1.2mm higher than that of the cutter, and the size of a gap between the metal enclosure and the cutter is 0.2-0.8 mm.

The method for depositing the diamond coating on the surface of the cutter can enable the cutter edge to grow the high-quality diamond coating which is strong in adhesive force, uniform in thickness and continuous and compact.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 shows a schematic structural diagram of a first viewing angle of an MPCVD carrier provided in the present application.

Fig. 2 shows a schematic structural diagram of a second viewing angle of an MPCVD carrier provided in the present application.

Figure 3 shows the GIXRD pattern of the surface coating at the cutting edge of the tool made in example 1 of the present application.

Fig. 4 shows a visible Raman plot of the surface coating at the cutting edge of the tool made in example 1 of the present application.

Fig. 5 shows an SEM image of the surface coating at the cutting edge of the tool made in example 1 of the present application.

Fig. 6 shows an SEM image of a cross section at the edge of a cutter made in example 1 of the present application.

Fig. 7 shows a highly magnified SEM image of fig. 6.

Fig. 8 shows an SEM image of the surface coating at the cutting edge of the tool made in comparative example 1 of the present application.

Fig. 9 shows an SEM image of the surface coating at the cutting edge of the tool made in comparative example 2 of the present application.

Icon: 100-MPCVD carrier; 110-a base station; 111-a placement area; 120-metal enclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following is a detailed description of an MPCVD carrier and a method for depositing a diamond coating on a tool surface according to embodiments of the present application.

Fig. 1 shows a schematic structural diagram of a first viewing angle of an MPCVD carrier 100 provided by the present application, and fig. 2 shows a schematic structural diagram of a second viewing angle of the MPCVD carrier 100 provided by the present application. Referring to fig. 1 and 2, MPCVD carrier 100 includes a base 110 and a metal dam 120 disposed on a surface of base 110 (metal dam 120 is represented by a filling pattern in fig. 2). The surface of the base platform 110 has a placement area 111 (the placement area 111 is an area surrounded by a dashed line in fig. 2), and the placement area 111 is used for carrying a substrate on which a film layer is to be deposited. The metal enclosure 120 is connected end to end and is arranged around the placement area 111. By way of example, the MPCVD carrier 100 provided herein can be used to deposit a film on a substrate surface having a film to be deposited thereon, and is particularly suitable for depositing a diamond coating on a substrate having a narrow sharp area on the surface, such as depositing a diamond coating on a tool surface (including at the edge of a knife).

In the present application, the metal surrounding barrier 120 is disposed end to end, which means that the metal surrounding barrier 120 is disposed in a closed sleeve shape around the outer circumference of the placement region 111, and no gap is formed on the sleeve surface.

The diamond coating cutter is easy to have tipping damage in the high-speed cutting process of high-hardness materials, so that the abrasion speed of the cutter is reduced; when the MPCVD carrier 100 provided by the application is used for depositing the diamond coating on the surface of the cutter, the metal enclosure 120 with a simple structure is arranged, so that the cutter edge can grow the high-quality diamond coating with strong adhesive force, uniform thickness and continuous compactness, the strength and wear resistance of the cutter edge can be enhanced, the wear failure of the cutter edge is delayed, the service life and cutting efficiency of the cutter are improved, the cutting area state of the cutter can be improved, the robustness of the cutter and the controllability of the workpiece processing surface quality are improved, the processing surface quality and precision of the cutter are ensured, and the comprehensive performance of the cutting cutter is improved.

In the application, the metal enclosure is made of molybdenum, tantalum or tungsten, and the metals are high-temperature-resistant and stable in physicochemical property, so that impurities are not easily generated in the MPCVD deposition process, and the growth of the diamond coating on the surface of the substrate is not influenced. In other embodiments of the present application, the material of the metal enclosure may also be selected from other high temperature resistant metal materials, for example, a metal material with a melting point of 2600 ℃.

Further, in the embodiment of the present application, the material of the metal enclosure is selected from molybdenum.

In the present embodiment, the MPCVD carrier 100 provided in the present application is used to deposit diamond coating on the tool surface, and the dimensions of the placement area 111 and the metal dam 120 need to be adjusted according to the actual tool size.

In this embodiment, the size of the placement area 111 matches the size of the area where the tool and the abutment 110 are in contact.

In the embodiment, the height of the metal enclosure 120 is 0-1.2mm higher than that of the cutter, which is beneficial to making the diamond coating grown on the cutting edge of the cutter have stronger adhesive force, more uniform thickness and higher compactness; if the height of the metal enclosure 120 is too high relative to the height of the tool, the diamond coating tends to be deposited on the surface of the metal enclosure 120 or the side wall of the metal enclosure 120, which is not favorable for the diamond deposition on the tool surface; if the height of the metal enclosure 120 is lower than the height of the tool, the quality of the diamond deposited on the surface of the tool is poor, and the tool has a short service life and is prone to edge breakage. Illustratively, the height of the metal fence 120 above the cutter may be 0mm, 0.2mm, 0.6mm, 0.8mm, or 1.2mm, etc. Further, the height of the metal fence 120 is 0.6mm higher than that of the cutter, so that the adhesion force of the diamond coating attached to the cutting edge of the cutter is stronger, the thickness of the diamond coating is more uniform, and the diamond coating is more compact.

In this embodiment, the size of the gap between the metal enclosure 120 and the cutting tool is 0.2-0.8mm, which can ensure that the diamond coating can be deposited on the surface of the cutting tool in the area where the diamond coating needs to be deposited, and is beneficial to improving the surface quality and the product yield of the cutting tool. Illustratively, the clearance between the metal fence 120 and the cutter may be in the size of 0.2mm, 0.4mm, 0.5mm, or 0.8mm, etc. Further, the gap size between the metal fence 120 and the cutter is 0.5 mm.

In this embodiment, the thickness of the metal dam 120 is 1.5-2.5 mm. Illustratively, the thickness of the metal dam 120 may be 1.5mm, 1.8mm, 2.0mm, 2.5mm, or the like. Further, the thickness of the metal fence 120 is 2.0 mm.

In this embodiment, since the shape of the used tool is substantially square, the shape of the used tool is matched with the shape of the tool, the shape of the metal enclosure 120 is also substantially square, and four right angles of the inner wall (i.e. the wall body facing the tool) of the metal enclosure 120 are provided with a chamfer structure, the radius of the chamfer is 1.0-1.5mm, which is beneficial to making the diamond coating adhered to the cutting edge of the tool have stronger adhesive force, more uniform thickness and higher compactness. Further, the radius of the chamfer is 1.2mm in size.

The present application also provides a method of depositing a diamond coating on a tool surface, comprising: the tool was placed on the placement area of the MPCVD carrier provided above and a diamond coating was deposited on the tool surface. Wherein the height of the metal enclosure is 0-1.2mm higher than that of the cutter, and the size of a gap between the metal enclosure and the cutter is 0.2-0.8 mm.

The method for depositing the diamond coating on the surface of the cutter provided by the application is characterized in that the MPCVD carrier provided by the application is used for bearing the cutter, so that the high-quality diamond coating which is strong in adhesive force, uniform in thickness and continuous and compact can be grown at the position of the cutter edge, the strength and the wear resistance of the cutter edge can be enhanced, the wear failure of the cutter edge is delayed, the service life and the cutting efficiency of the cutter are improved, the cutting area state of the cutter can be improved, the robustness of the cutter and the controllability of the quality of the machined surface of a workpiece are improved, the quality and the precision of the machined surface of the cutter are ensured, and the comprehensive performance of the cutting cutter is improved.

In this embodiment, the thickness of the metal enclosure is 1.5-2.5 mm.

In the present application, the material of the cutting tool is selected from high-speed steel, cemented carbide, silicon nitride ceramic, polycrystalline diamond or polycrystalline cubic boron nitride. Further, in the embodiment of the present application, the material of the cutting tool is selected from silicon nitride ceramics.

In this embodiment, the tool needs to be cleaned before the diamond coating is deposited on the surface of the tool, so as to obtain a clean tool, which is beneficial to better deposit the diamond coating later. Specifically, the cleaning treatment comprises subjecting the cutter to ultrasonic treatment in the solution for 5-20min, and drying the cutter at 40-60 deg.C for 10-30 mm. As an example, the solution for sonicating the cutter may be selected from acetone or ethanol, and the like.

In this embodiment, after the cleaning treatment of the cutting tool, the polishing treatment of the cutting tool is further performed to make the surface of the cutting tool bright, reduce the surface roughness of the cutting tool, increase nucleation sites on the surface of the cutting tool, and facilitate the improvement of the nucleation density of the subsequent diamond growth on the surface of the cutting tool, thereby facilitating the improvement of the compactness and continuity of the diamond film. Specifically, the polishing treatment comprises dry polishing the cutter in diamond powder with a particle size of 0.1-30 μm for 14-45 min.

After the polishing treatment, the polished cutter is placed on the placing area of the MPCVD carrier, and then a diamond coating is deposited on the surface of the cutter. In this embodiment, the step of depositing a diamond coating on the tool surface comprises: under the vacuum condition, introducing a first reaction source gas for an excitation reaction; then, a second reaction source gas is introduced to carry out deposition reaction.

And introducing a first reaction source gas, exciting the first reaction source gas by using microwaves to generate plasma spheres, and introducing a second reaction source gas to ensure that the diamond can be nucleated and grown on the surface of the cutter.

In this embodiment, the first precursor gas includes a precursor gas, and the precursor gas includes hydrogen. Further, in some embodiments of the present application, the first precursor gas further comprises a carrier gas comprising at least one of nitrogen and argon.

In this embodiment, the second precursor gas includes at least one of methane, acetylene, and ethylene.

In this embodiment, the volume ratio of the second precursor gas to the precursor gas is (3-5): 50, the nucleation density of the diamond can be improved under the above proportion, and the compactness of the diamond coating is favorably improved; meanwhile, if the proportion of the second reaction source gas is too high, the concentration of precursor gas in the system is reduced, the etching effect of active hydrogen atoms on the surface of the cutter is weakened, non-diamond phase components generated on the surface of the cutter are easily increased, and the purity and the quality of a diamond film on the surface of the cutter are not ensured; if the precursor gas content is too high, the deposition rate of diamond and the color of the diamond film may be reduced. As an example, the volume ratio of the second precursor gas to the precursor gas may be 3: 50. 3.5: 50. 4.0: 50. 4.5: 50 or 5:50, etc. Further, a volume ratio of the second precursor gas to the precursor gas is 3.5: 50.

in this embodiment, the excitation power of the excitation reaction is 500-700W, the gas pressure of the excitation reaction is 8-12Torr, the shape and energy density of the plasma can be precisely controlled under the above excitation conditions, the density uniformity of the excited plasma sphere is improved to reduce the concentration gradient of various active substances required for depositing diamond, and a high-quality diamond coating with uniform and high adhesion and continuous and dense thin film can be obtained on the surface and the cutting edge of the hard cutting tool. Illustratively, the excitation power for exciting the reaction may be 500W, 550W, 600W, 700W, or the like, and the gas pressure for exciting the reaction may be 8Torr, 10Torr, 12Torr, or the like.

In this embodiment, the deposition power of the deposition reaction is 1000-2400W, and the pressure of the deposition reaction is 20-70Torr, so that the concentration gradient of various active substances required for depositing diamond can be eliminated, which is beneficial to improving the film quality and structure stability of the diamond coating, and is beneficial to obtaining a high-quality diamond coating with uniform and high adhesion and continuous and compact film on the surface and cutting edge of the hard cutting tool. Illustratively, the deposition power of the deposition reaction may be 1000W, 1500W, 2000W, 2400W, or the like, and the pressure of the deposition reaction may be 20Torr, 50Torr, 55Torr, or 70Torr, or the like.

Furthermore, the temperature of the deposition reaction is 980-1180 ℃, the time of the deposition reaction is 11-20 hours, the uniformity and the deposition rate of a temperature field of the deposition of the diamond coating can be improved, the thickness of the diamond coating is controlled, the thermal state of the cutter is improved, the temperature gradient of the surface where the diamond coating grows is eliminated, the film quality and the structural stability of the diamond coating are favorably improved, and the surface and the cutting edge part of the hard cutting cutter are favorably provided with the uniform and high-quality diamond coating with high adhesive force and continuous and compact film. Illustratively, the temperature of the deposition reaction may be 980 ℃, 1030 ℃, 1080 ℃, 1130 ℃, or 1180 ℃, etc., and the time of the deposition reaction may be 11h, 12h, 15h, 18h, or 20h, etc.

The method for depositing the diamond coating on the surface of the cutter has at least the following advantages:

the method for depositing the diamond coating on the surface of the cutter is adopted to deposit the diamond coating on the surface of the cutter, the diamond coating can be directly deposited on the surface of the cutter (including a cutting edge) without preparing a transition layer or a buffer layer on the surface of a cutter substrate in advance, the prepared diamond coating on the cutting edge and the edge of the cutter is strong in adhesive force, uniform in thickness, continuous and compact, and the thickness of the diamond coating is easy to regulate and control and is approximately 0.05-10 mu m; in the subsequent use process of the cutter, the diamond coating is not easy to crack and peel, so that the phenomena of edge breakage and edge gnawing which are easy to occur when the cutter is used for processing and cutting high-hardness materials are effectively avoided, the process is simple, and large-scale production can be realized.

The features and properties of the MPCVD carrier and the method of depositing a diamond coating on a tool surface provided herein are described in further detail below with reference to the examples.

Example 1

The present embodiments provide an MPCVD carrier and a method for depositing a diamond coating on a tool surface, wherein the tool dimensions are: the length is 12.7mm, the width is 12.7mm, and the height is 5 mm.

The MPCVD carrier comprises a base platform with a placing area and a metal enclosure. The size of the placement area is 12.7 x 12.7mm, and the metal enclosing barriers are arranged around the placement area in an end-to-end enclosing mode. The metal enclosure is made of molybdenum. The metal enclosure is square, the height is 5.6mm, the thickness is 2.0mm, and the gap between the metal enclosure and the cutter is 0.5 mm; four right angles of the inner wall of the metal enclosure are provided with chamfer structures with the radius size of 1.2 mm.

The method for depositing the diamond coating on the surface of the cutter comprises the following steps:

(1) ultrasonically treating a silicon nitride cutter in an acetone solution for 10min, and then drying at 50 ℃ for 20 min; then the cutter is dry-polished in diamond powder with the particle size of 10 mu m for 30min until the surface is bright.

(2) And (2) placing the cutter processed in the step (1) in a placing area of the MPCVD carrier of the carrier in an MPCVD system, introducing hydrogen under the vacuum condition, and exciting for 2min under the excitation power of 600W under the reaction chamber pressure of 10 Torr.

(3) And continuously introducing methane, and depositing for 10 hours under the pressure of a reaction cavity with the pressure of 50Torr, the temperature of 1080 ℃ and the deposition power of 2000W to prepare the cutter with the diamond coating deposited on the surface.

Wherein the volume ratio of methane to hydrogen is 3.5: 50.

Example 2

Example 2 differs from example 1 in that the height of the metal surround is 5 mm.

Example 3

Example 3 differs from example 1 in that the volume ratio of methane to hydrogen in step (3) is 8: 50.

Example 4

Example 4 differs from example 1 in that the pressure in the reaction chamber in step (3) was 15Torr and the deposition power was 800W.

Comparative example 1

Comparative example 1 differs from example 1 in that the MPCVD carrier consists of only a base having a placement area where the tool is placed when the diamond coating is deposited on the tool surface.

Comparative example 2

Comparative example 2 differs from example 1 in that the MPCVD carrier comprises a base having a placement region and metal protrusions spaced around the periphery of the placement region; wherein, the metal bulge is cylindric and diameter is 2.0mm, and height is 5.6mm, and the distance between the adjacent metal bulge is 0.5 mm.

Comparative example 3

Comparative example 3 differs from example 1 in that the MPCVD carrier has a metal fence height of 3.0 mm.

Test example 1

The surface coating layer at the cutting edge of the cutting tool with the diamond coating layer deposited on the surface, which is prepared in the example 1, is subjected to grazing incidence X-ray diffraction (GIXRD) and Raman (Raman) spectrum characterization, the GIXRD characterization result is shown in figure 3, and the visible light Raman characterization result is shown in figure 4.

As can be seen from fig. 3, there are two distinct sharp diffraction peaks at 44 ° 2 θ and 76 ° 2 θ, corresponding to the (111) and (220) crystal planes of diamond, respectively, indicating that the diamond coating deposited on the surface at the cutting edge of the tool has a higher crystallinityAnd grain orientation density. As can be seen from FIG. 4, at 1332cm ^-1 A sharp diamond characteristic peak (D peak) with higher strength appears at 1480-1520cm ^-1 The broad peak at which corresponds to sp ² The above results demonstrate that a high quality diamond coating can be formed at the tool edge and on the tool surface using the method of depositing a diamond coating on the tool surface as provided in example 1.

Test example 2

Scanning Electron Microscope (SEM) characterization was performed on the surface-deposited diamond coated tools manufactured in example 1, comparative example 1, and comparative example 2, and SEM topography maps of the blade surface of the tool of example 1 are shown in fig. 5, of the blade cross-section of the tool of example 1 are shown in fig. 6 and 7, and of the blade surface of the tools of comparative example 1 and comparative example 2 are shown in fig. 8 and 9, respectively.

As can be seen from fig. 5, the surface at the edge of the tool has a dense, continuous and uniform diamond coating; and the diamond coating on the surface of the cutter and the cutting edge is complete without falling off, which shows that the binding force between the diamond coating and the cutter is strong. As can be seen from fig. 6, the cross section at the edge of the tool (i.e. the edge core) has high uniformity of diamond grain size and high nucleation density, which indicates that the method for depositing diamond coating on the surface of the tool provided in example 1 can form dense, continuous and uniform high-quality diamond coating on both the surface at the edge and the core at the edge. Fig. 7 is an enlarged view of fig. 6, and it can be seen from fig. 7 that diamond particles are dense and full, which can protect the tool well, and is beneficial to enhancing the cutting performance and wear resistance of the tool, delaying the wear failure of the cutting edge, improving the life and cutting efficiency of the tool, and improving the robustness of the tool and the controllability of the quality of the machined surface of the workpiece. The diamond coating formed on the surface of the cutter in the comparative example 1 has uneven particle size distribution, poor compactness of the diamond coating, uneven thickness of the diamond coating and obvious coating falling phenomenon, which shows that the metal enclosure arranged around the placing area of the surface of the MPCVD carrier can not effectively form a compact, continuous, uniform and strong-bonding-force diamond coating on the surface of the blade. The diamond coating formed on the surface of the cutter of comparative example 2 was peeled off, indicating that the diamond coating having a strong bonding force with the surface of the cutter could not be effectively formed only by disposing the metal protrusions at intervals around the placement region.

Test example 3

The tools with diamond coatings deposited on the surfaces, which were prepared in examples 1 to 4 and comparative examples 1 to 3, were characterized, and the results are shown in table 1.

TABLE 1

Description of the drawings: in Table 1, "tool life at a cutting speed of 100 m/min" is a time period for which the tool obtained in examples 1 to 4 and comparative examples 1 to 3 can be used normally when the tool is used for cutting hardened steel GCr 15; "whether or not chipping occurred" is whether or not chipping occurred in the tool after the cutting operation of the hardened steel GCr15 was performed on the tools obtained in examples 1 to 4 and comparative examples 1 to 3.

As can be seen from Table 1, the surface roughness and the coefficient of friction of the cutting tools obtained in examples 1-2 are lower than those of the cutting tools obtained in comparative examples 1-3, and the cutting performance of the cutting tools obtained in examples 1-2 is significantly better than that of the cutting tools obtained in comparative examples 1-3, indicating that the structure of the metal dam and the relationship between the height of the metal dam and the height of the cutting tool can affect the quality of the diamond coating deposited on the surface of the cutting tool. Specifically, as can be seen from comparison between the embodiment 1 and the embodiment 2, when the height of the metal enclosure is higher than the specific height of the tool, the diamond nucleation density of the diamond coating on the surface of the tool is higher and the diamond coating compactness is higher (i.e. the quality of the diamond coating is higher) relative to the case that the height of the metal enclosure is equal to the height of the tool, so that the service life and the cutting performance of the tool are further improved; compared with the comparative example 1, the quality of the diamond coating deposited on the surface of the cutter can be obviously improved when the metal enclosure is arranged around the cutter and the diamond coating is directly deposited on the surface of the cutter without the metal enclosure; as can be seen from the comparison between the embodiment 1 and the comparative example 2, when the metal enclosure is arranged around the cutter in an end-to-end manner and gaps are arranged on the metal enclosure relative to the metal enclosure so as to deposit the diamond coating on the surface of the cutter, the quality of the diamond coating deposited on the surface of the cutter can be further improved; it can be seen from the comparison of examples 1-2 with comparative example 3 that the quality of the diamond coating deposited on the surface of the tool can be further improved when the height of the metal dam is higher than the specific height of the tool or when the height of the metal dam is equal to the height of the tool compared to when the height of the metal dam is lower than the height of the tool. Meanwhile, the tool performance ranking obtained in examples 1-2 and comparative examples 1-3 is as follows: example 1 > example 2 > comparative example 3 > comparative example 1, indicating that the absence of a metal dam or the height of the metal dam below the height of the tool is more influential in the quality of the diamond coating deposited on the surface of the tool than if there were gaps in the metal dam.

The surface roughness and the friction coefficient of the cutter obtained in the example 1 are lower than those of the cutters obtained in the examples 3-4, and the cutting performance of the cutter obtained in the example 1 is obviously better than that of the cutters obtained in the examples 3-4, which shows that the volume ratio of methane to hydrogen and the reaction gas pressure and the deposition power of the deposition reaction can influence the quality of the diamond coating deposited on the surface of the cutter. Specifically, by comparing example 1 with example 3, it is shown that too high a methane content ratio in the deposition reaction tends to increase the content of non-diamond phase generated on the surface of the tool, thereby reducing the quality of diamond deposited on the surface of the tool; by comparison of example 1 with example 4, it is shown that lower reaction pressure and deposition power of the deposition reaction can reduce the quality of the diamond deposited on the tool surface, because the reaction pressure and deposition power of the deposition reaction can affect the temperature of the deposition reaction, and lower deposition temperature can cause the plasma density to decrease, the growth rate of the diamond to decrease, and the ratio of graphite to amorphous carbon in the coating on the tool surface to increase, which is not favorable for the formation of a uniform, dense and continuous high quality diamond coating on the tool surface. Furthermore, the cutting performance of the cutting tools obtained in examples 3-4 was superior to that of the cutting tool obtained in comparative example 1, indicating that the absence of a metal fence at the periphery of the cutting tool more affects the quality of the diamond coating produced on the surface of the cutting tool than the ratio of methane to hydrogen in the deposition reaction and the condition parameters of the deposition reaction.

In conclusion, the method for depositing the diamond coating on the surface of the cutter provided by the application has the advantages that the MPCVD carrier is used for bearing the cutter, so that the high-quality diamond coating which is strong in adhesive force, uniform in thickness, continuous and compact can grow at the position of the cutter edge, the strength and the wear resistance of the cutter edge can be enhanced, the wear failure of the cutter edge is delayed, the service life and the cutting efficiency of the cutter are improved, the cutting area state of the cutter can be improved, the robustness of the cutter and the controllability of the quality of the machined surface of a workpiece are improved, the quality and the precision of the machined surface of the cutter are ensured, and the comprehensive performance of the cutting cutter is improved.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An MPCVD carrier, comprising:

a base platform, wherein the surface of the base platform is provided with a placing area; and

the metal that connects end to end encloses the fender, the metal encloses the fender set up in the surface of base station encloses and locates place regional all around.

2. The MPCVD carrier of claim 1, wherein the metal dam is made of a material selected from the group consisting of molybdenum, tantalum, and tungsten.

3. A method of depositing a diamond coating on a tool surface, comprising: placing a tool on the placement area of the MPCVD carrier of claim 1 or 2 and depositing a diamond coating on the tool surface;

the height of the metal enclosing barrier is 0-1.2mm higher than that of the cutter, and the size of a gap between the metal enclosing barrier and the cutter is 0.2-0.8 mm.

4. A method of depositing a diamond coating on a tool surface as claimed in claim 3, wherein the thickness of the metal dam is 1.5-2.5 mm.

5. The method of claim 3, wherein the step of depositing a diamond coating on the tool surface comprises: under the vacuum condition, introducing a first reaction source gas for an excitation reaction; then introducing a second reaction source gas for deposition reaction;

the first precursor gas comprises a precursor gas comprising hydrogen;

the second precursor gas comprises at least one of methane, acetylene, and ethylene;

the volume ratio of the second reaction source gas to the precursor gas is (3-5): 50;

optionally, the first precursor gas further comprises a carrier gas comprising at least one of nitrogen and argon.

6. The method of claim 5, wherein the excitation power of the excitation reaction is 500-700W, and the gas pressure of the excitation reaction is 8-12 Torr; the deposition power of the deposition reaction is 1000-2400W, and the gas pressure of the deposition reaction is 20-70 Torr.

7. The method for depositing the diamond coating on the surface of the cutting tool as claimed in claim 5, wherein the temperature of the deposition reaction is 980-1180 ℃, and the time of the deposition reaction is 11-20 h.

8. The method of claim 3, further comprising polishing the tool prior to said depositing a diamond coating on the tool surface; the polishing treatment comprises dry polishing the cutter in diamond powder with the grain diameter of 0.1-30 μm for 14-45 min.

9. The method of claim 8, further comprising cleaning the tool prior to the polishing process; the cleaning treatment comprises the steps of carrying out ultrasonic treatment on the cutter in a solution for 5-20min, and then drying the cutter at 40-60 ℃ for 10-30 min;

alternatively, the solution is selected from acetone or ethanol.

10. A method of depositing a diamond coating on a tool surface as claimed in any one of claims 3 to 9, wherein the tool material is selected from high speed steel, cemented carbide, silicon nitride ceramic, polycrystalline diamond or polycrystalline cubic boron nitride.