Alloy tool with multilayer hard coating structure

Abstract

The utility model provides a kind of alloy cutter of multilayer hard coating structure, including cutter blade main body, the cutter blade main body center is passed through and is provided with mounting hole, its upper and lower surfaces are respectively provided with chip groove and anti-sticking protrusion;The surface of the cutter blade main body is provided with base coating, and the upper and lower surfaces are sequentially provided with stepped transition coating and hard coating on the base coating basis, and the side of the cutter blade main body is provided with heat dissipation hard coating;The utility model is different surface of cutter and is differentiated with coating: upper and lower surfaces are connected base coating and hard coating with stepped transition coating, and the combination strength and wear resistance are improved;Side is provided with thicker heat dissipation hard coating, and high-efficiency heat conduction is realized;“wear-resistant-heat dissipation” is coordinated, and service life is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of alloy cutting tool technology, and in particular relates to an alloy cutting tool with a multi-layer hard coating structure. Background Technology

[0002] In the field of machining, alloy cutting tools are the core tools for material cutting and forming, and their performance directly affects machining efficiency, workpiece accuracy, and tool life. With the increasing application of difficult-to-machine materials (such as titanium alloys, high-temperature alloys, and high-strength stainless steel) in industries such as aerospace and automotive manufacturing, the working conditions faced by cutting tools during the cutting process are becoming increasingly demanding, including high temperature, high friction, and high impact. Traditional alloy cutting tools with single coatings or simple composite coatings can no longer meet the requirements.

[0003] Currently, the coatings of conventional alloy cutting tools mostly adopt a uniform structure, meaning that the top and bottom surfaces and the sides of the tool use the same coating combination and thickness design. However, the different surfaces of the tool perform significantly different functions during the cutting process: the top and bottom surfaces, as the main areas in direct contact with the chips, must withstand the intense friction and compression of the chips, requiring extremely high wear resistance and resistance to crater wear of the coating; while the sides mainly contact the machined surface of the workpiece, and in addition to having a certain degree of wear resistance, they must also dissipate the heat generated during the cutting process in a timely manner—if heat accumulates, it can easily lead to coating oxidation failure or softening of the tool substrate, thereby causing failures such as chipping and rolling.

[0004] Therefore, it is essential to invent an alloy cutting tool with a multi-layer hard coating structure. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides an alloy cutting tool with a multi-layer hard coating structure, including a cutting tool body, a mounting hole, a chip groove, an anti-sticking protrusion, a base coating, a stepped transition coating, a hard coating, and a heat dissipation hard coating. The cutting tool body has a mounting hole through its center, and chip grooves and anti-sticking protrusions are respectively provided on its upper and lower surfaces. The surface of the cutting tool body is provided with a base coating, and its upper and lower surfaces are successively provided with a stepped transition coating and a hard coating on the basis of the base coating. The side of the cutting tool body is provided with a heat dissipation hard coating.

[0006] Preferably, the blade body is an equilateral triangle structure, and its upper surface is provided with an arc-shaped chip groove, which is arranged adjacent to the anti-sticking protrusion.

[0007] Preferably, the outer surface of the cutting tool blade body, including the chip groove and the anti-sticking protrusion surface, is provided with a base coating, which is a full-coverage coating.

[0008] Preferably, the upper and lower surfaces of the cutting tool body, including the base coating with chip grooves and anti-sticking protrusions, are provided with a stepped transition coating and a hard coating, wherein the stepped transition coating is disposed between the base coating and the hard coating.

[0009] Preferably, a heat-dissipating hard coating is provided on the base coating on the side of the cutting tool blade body, and the thickness of the heat-dissipating hard coating is greater than or equal to the sum of the thicknesses of the stepped transition coating and the hard coating.

[0010] Compared with the prior art, the present invention has the following beneficial effects: This invention features a stepped transition coating and a hard coating sequentially applied to the top and bottom surfaces on a base coating, while the sides have a heat-dissipating hard coating applied to the base coating. This design precisely matches the working characteristics of each surface—the hard coating on the top and bottom surfaces enhances wear resistance, while the stepped transition coating improves the bonding strength between the coating and the substrate and the hard coating, effectively resisting chip friction and impact; the heat-dissipating hard coating on the sides enhances heat conduction and dissipation, preventing coating failure due to high temperatures. This achieves synergistic optimization of "wear resistance and heat dissipation," significantly broadening the applicable working conditions of the tool (especially suitable for high-speed cutting or dry cutting of difficult-to-machine materials). This invention utilizes a stepped transition coating between the base coating and the hard coating to gradually buffer the performance differences (such as hardness and coefficient of thermal expansion) between different coatings, reducing interfacial stress concentration. Compared to traditional directly stacked coating structures, this design effectively prevents the hard coating from cracking or peeling due to impact or thermal stress, significantly improving the overall stability of the coating system. Simultaneously, the gradient properties of the stepped transition coating provide excellent support for the hard coating, ensuring it maintains superior wear resistance under high-load cutting conditions.

[0011] The thickness of the side-heat-dissipating hard coating in this invention is set to be greater than or equal to the sum of the thicknesses of the stepped transition coating and the hard coating. The thicker coating increases the coverage along the heat conduction path. Combined with the high thermal conductivity of the hard coating itself, it can more efficiently dissipate heat generated during cutting from the side, reducing the overall tool temperature. This design effectively alleviates problems such as coating oxidation and reduced substrate strength caused by insufficient side heat dissipation in traditional tools, extending the tool's service life. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0013] Figure 2 This is a partial cross-sectional structural diagram of the present invention.

[0014] Figure 3 This is a utility model Figure 2 A magnified schematic diagram of the structure at point A.

[0015] In the picture: Tool blade body 1, mounting hole 2, chip groove 3, anti-sticking protrusion 4, base coating 5, stepped transition coating 6, hard coating 7, heat dissipation hard coating 8. Detailed Implementation

[0016] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0017] In the description of the embodiments, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present utility model based on the specific circumstances.

[0018] As attached Figure 1 To be continued Figure 3 As shown: This utility model provides an alloy cutting tool with a multi-layer hard coating structure, including a cutting tool body 1, a mounting hole 2, a chip groove 3, an anti-sticking protrusion 4, a base coating 5, a stepped transition coating 6, a hard coating 7, and a heat-dissipating hard coating 8. The cutting tool body 1 has a mounting hole 2 through its center, and chip groove 3 and anti-sticking protrusion 4 are respectively provided on its upper and lower surfaces. The surface of the cutting tool body 1 is provided with a base coating 5, and the upper and lower surfaces are respectively provided with a stepped transition coating 6 and a hard coating 7 on the basis of the base coating 5. The side of the cutting tool body 1 is provided with a heat-dissipating hard coating 8.

[0019] Furthermore, the tool insert body 1 is made of cemented carbide and is machined into an equilateral triangle structure, with all three vertices rounded to enhance the strength of the cutting tip during cutting. An arc-shaped chip groove 3 is integrally formed along the edge of the triangle on the outer periphery of the upper surface of the tool insert body 1, with a smooth curved surface transition at the bottom. The chip groove 3 and anti-sticking protrusions 4 are arranged adjacent to each other. The anti-sticking protrusions 4 are micron-level protrusions evenly distributed along the inner edge of the chip groove 3. Both are formed simultaneously through precision milling and sandblasting processes on the tool body surface, forming a "groove-protrusion" mating structure to collaboratively guide the chip flow.

[0020] Furthermore, the outer surface (including the upper and lower surfaces and side surfaces) of the cutting tool body 1, as well as the inner surface of the chip groove 3 and the top and side surfaces of the anti-adhesion protrusion 4, are all coated with a base coating 5 using a physical vapor deposition (PVD) process. The base coating 5 is made of TiN or CrN material, with a thickness controlled between 1.0 and 2.0 μm. It is applied using a continuous film formation method that covers the entire surface, with no significant thickness attenuation in the curved areas of the chip groove 3 and at the corners of the anti-adhesion protrusion 4 (thickness deviation ≤ 0.2 μm). This base coating 5 forms a metallurgical bond with the surface of the cutting tool body 1 through ion bombardment pretreatment, and its surface roughness Ra ≤ 0.3 μm, providing a smooth substrate for subsequent coatings and initially improving the anti-adhesion performance of the cutting tool surface.

[0021] Furthermore, on the upper and lower surfaces of the cutting tool body 1, and on the base coating 5 covering the inner surface of the chip groove 3 and the surface of the anti-sticking protrusion 4, a stepped transition coating 6 and a hard coating 7 are sequentially superimposed by a high-power pulsed magnetron sputtering (HiPIMS) process. Among them, the stepped transition coating 6 is tightly bonded to the upper surface of the base coating 5. It adopts a TiAlN-TiAlSiN composition gradient design with a thickness of 2.0~3.0μm. From the bonding surface with the base coating 5 to the top surface, the Al element content gradually increases from 35% to 60%, and the Si element content gradually increases from 0% to 8%, achieving a smooth transition in hardness from HV2800 to HV3400. The hard coating 7 tightly covers the upper surface of the stepped transition coating 6. It is made of AlCrN material with a thickness of 1.5~2.5μm and a hardness of HV3600~3800. It maintains complete coverage on the top surface of the anti-sticking protrusion 4 and forms a continuous crack-free film structure at the bottom and wall of the chip groove 3. Together with the stepped transition coating 6, it forms a high wear-resistant protection system for the upper and lower surfaces.

[0022] Furthermore, a heat-dissipating hard coating 8 is formed on the base coating 5 on the side of the tool insert body 1 using a chemical vapor deposition (CVD) process. The heat-dissipating hard coating 8 is a composite structure of Al2O3 and TiSiN (Al2O3 accounts for 70%), with a thickness of 5.0~7.0 μm, which is greater than or equal to the sum of the thicknesses of the stepped transition coating 6 (2.0~3.0 μm) and the hard coating 7 (1.5~2.5 μm). This coating is tightly bonded to the base coating 5 on the side through an intermediate TiAlN transition layer (0.5 μm thick), and its thermal conductivity can reach 30~40 W / (m・K). At the junction of the side and the upper and lower surfaces, a smooth transition coating edge (rounded corner radius ≥0.1 mm) is formed, which avoids stress concentration at the corners of the coating and can quickly dissipate cutting heat through the relatively thick coating and high thermal conductivity.

[0023] The working principle is as follows: First, the main body 1 of the cutting tool insert achieves stable assembly with the tool holder through the central mounting hole 2. The equilateral triangle structure and the rounded transition design at the apex provide a stable foundation for cutting. The chip grooves 3 on its upper and lower surfaces work together with the anti-sticking protrusions 4. The chip grooves 3 guide the chips to be discharged along the preset path with the help of the arc surface. The anti-sticking protrusions 4 reduce the contact area between the chips and the surface of the cutting tool through micron-level protrusions, so as to avoid the chips sticking together and affecting the processing.

[0024] Secondly, the base coating 5 fully covers all surfaces of the blade and the details of the chip groove 3 and anti-sticking protrusions 4 through PVD process, forming a strong metallurgical bond with the blade body. This not only provides a smooth substrate for subsequent coatings, but also initially improves the anti-sticking ability based on its own performance.

[0025] Furthermore, a stepped transition coating 6 and a hard coating 7 are sequentially applied to the upper and lower surfaces of the blade on the base coating 5. The stepped transition coating 6 is designed with a composition gradient to buffer the performance difference between the base coating and the hard coating, avoiding stress concentration at the interface. The hard coating 7, with its high hardness, forms a protective layer in easily worn areas such as chip grooves and anti-sticking protrusions, thus jointly enhancing the ability of the upper and lower surfaces to resist chip friction and impact.

[0026] Finally, the heat dissipation hard coating 8 on the side of the blade relies on its thick coating thickness and high thermal conductivity to quickly dissipate the heat generated during cutting. It is also tightly bonded to the base coating through a transition layer, and the smooth transition design at the corners avoids stress concentration in the coating, ensuring heat dissipation and coating stability, thereby achieving high efficiency in the overall cutting performance of the tool.

[0027] Any technical solution that achieves the above-mentioned technical effects by utilizing the technical solution described in this utility model, or by designing a similar technical solution inspired by the technical solution described in this utility model, falls within the protection scope of this utility model.

Claims

1. A multi-layer hard-coated alloy cutting tool, characterized in that, The tool includes a cutting tool body (1), a mounting hole (2), a chip groove (3), an anti-sticking protrusion (4), a base coating (5), a stepped transition coating (6), a hard coating (7), and a heat dissipation hard coating (8). The cutting tool body (1) has a mounting hole (2) through its center, and a chip groove (3) and an anti-sticking protrusion (4) are respectively provided on its upper and lower surfaces. The surface of the cutting tool body (1) is provided with a base coating (5), and its upper and lower surfaces are provided with a stepped transition coating (6) and a hard coating (7) in sequence on the basis of the base coating (5). The side of the cutting tool body (1) is provided with a heat dissipation hard coating (8).

2. The alloy cutting tool with a multi-layer hard coating structure as described in claim 1, characterized in that: The blade body (1) is an equilateral triangle structure, and the outer periphery of its upper surface is provided with a chip groove (3) of arc geometry. The chip groove (3) and the anti-sticking protrusion (4) are arranged adjacent to each other.

3. The alloy cutting tool with a multi-layer hard coating structure as described in claim 2, characterized in that: The outer surface of the cutting tool blade body (1), including the chip groove (3) and the anti-sticking protrusion (4), is provided with a base coating (5), which is a full-coverage coating.

4. The alloy cutting tool with a multi-layer hard coating structure as described in claim 3, characterized in that: The upper and lower surfaces of the cutting tool body (1), including the chip groove (3) and the anti-sticking protrusion (4), are provided with a stepped transition coating (6) and a hard coating (7) on the basis of the base coating (5), and the stepped transition coating (6) is disposed between the base coating (5) and the hard coating (7).

5. The alloy cutting tool with a multi-layer hard coating structure as described in claim 4, characterized in that: A heat-dissipating hard coating (8) is provided on the base coating (5) on the side of the blade body (1). The thickness of the heat-dissipating hard coating (8) is greater than or equal to the sum of the thicknesses of the stepped transition coating (6) and the hard coating (7).

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