CN111235526A - A kind of cutting tool comprising nanometer multi-layer coating, manufacturing method and application thereof - Google Patents

Abstract

The invention discloses a cutting tool comprising a nanometer multi-layer coating, a manufacturing method and an application thereof. The cutting tool comprises a substrate and a coating applied on the substrate. The first-zone coating, the second-zone coating and the third-zone coating, wherein the second-zone coating comprises at least one set of stacked layers of Ti _1-a Al _a N nano-coatings and a layer of NbN Ti _1-a Al _a N/NbN unit nano-coating group formed by nano-coating, 0.1≤a≤0.9. Compared with the prior art, the cutting tool of the present invention has higher anti-chipping performance and longer service life of the cutting tool.

Description

A kind of cutting tool comprising nanometer multi-layer coating, manufacturing method and application thereof

technical field

The invention belongs to the field of material processing, and in particular relates to a cutting tool comprising a nanometer multi-layer coating, a manufacturing method and an application thereof.

Background technique

The performance of materials has been continuously improved with the development of industrial technology. In the field of material applications, the proportion of high-performance and difficult-to-machine materials such as titanium alloys, nickel-based alloys, and stainless steels is increasing year by year. Tool requirements are also increasing year by year. The processing of difficult-to-machine materials has high requirements on the overall performance of the tool, and it will be a higher challenge for the tool material and surface coating technology, especially the tool coating technology. How to improve the machining efficiency and life of the tool through the innovation of tool coating technology has become an important research hotspot.

Cutting tool surface coating can greatly improve the surface hardness, wear resistance and high temperature resistance of the tool, and has a significant effect on improving tool life and machining quality. The study found that by modifying the thickness of the modulation period, a nanostructured tool coating with the best performance can be obtained within a certain range.

NbN coating has good thermal stability, high hardness, excellent mechanical properties, physical properties and chemical stability, so NbN coating has a wide range of application prospects in various fields.

CN106573313B discloses a cutting tool, the cutting tool comprises a base material and a coating on the surface of the base material, and the coating is a composite structural coating comprising an outer layer and an inner layer coating, wherein the outermost coating layer contains cubic structure NbN Mixed structure NbN with hexagonal structure NbN, and the coating contains 2 kinds of doping elements, while the inner layer coating compound does not contain Nb element.

CN104508185B discloses a cutting tool insert, which comprises a cemented carbide substrate and a double-layer structural coating, wherein one layer is a NbN coating with a thickness of 0.5-5 μm, and the NbN coating contains Ti, Zr or Cr on the substrate A titanium-aluminum nitride coating is contained between the NbN layer and the thickness is 0.5-5 μm.

CN109415799A discloses a tool comprising a NbN coating, the thickness of the NbN coating is 0.2-15 μm, the NbN layer comprises a phase mixture of cubic structure c-NbN and hexagonal structure h-NbN, and the cubic structure NbN content is not less than 40% .

Although the cutting tools using the pure NbN coating in the prior art and the multi-layer coating containing NbN have achieved good cutting performance, there are still micro-chipping and rapid oxidation during the cutting process. Therefore, the chipping resistance and high temperature oxidation resistance of the coating can be improved by optimizing the coating structure, thereby further improving the cutting performance of the coated tool.

SUMMARY OF THE INVENTION

In order to solve the defects and deficiencies in the prior art, an object of the present invention is to provide a cutting tool with higher resistance to microchipping, high temperature oxidation resistance and longer service life.

To achieve the above object, the present invention realizes through the following technical solutions:

A cutting tool comprising a nano-multilayer coating, characterized in that it comprises a substrate and a coating applied on the substrate, the coating comprises a second zone coating, and the second zone coating comprises at least one group of A Ti _1-a Al _a N/NbN unit nano-coating group formed by a stacked layer of Ti _1-a Al _a N nano-coating and a layer of NbN nano-coating, wherein 0.1≤a≤0.9. It can reduce the generation of built-up edge, reduce friction, improve the resistance to microchipping and wear resistance, thereby prolonging the life of the tool.

In one embodiment, in the Ti _1-a Al _a N/NbN unit nano-coating group, the thickness of the Ti _1-a Al _a N nano-coating is 0.1-100 nm, and the thickness of the NbN nano-coating is 0.1-100 nm. 0.1-100nm.

In one embodiment, in the Ti _1-a Al _a N/NbN unit nano-coating group, the sum of the thicknesses of the single-layer Ti _1-a Al _a N and the single-layer NbN (ie, the coating modulation period) is 0.2 -200nm.

In one embodiment, the group number of the Ti _1-a Al _a N/NbN unit nano-coating group is 1-100 groups. The periodic structure is modulated by designing multiple groups of Ti _1-a Al _a N/NbN unit nano-coating groups, so that each Ti _1-a Al _a N coating and NbN coating are nano-scale coatings. The optimal design of thickness and modulation period thickness enables the formed Ti _1-a Al _a N/NbN unit nano-coating group to obtain higher hardness due to the fine-grain strengthening effect.

In one of the embodiments, the hardness of the Ti _1-a Al _a N/NbN unit nano-coating group is 25-45 GPa. The hardness is the hardness data of the coating obtained by the nanoindentation method. During the test, the indentation depth should be reasonably matched with the coating thickness or total thickness. Improper matching of the indentation depth with the coating thickness or total thickness, resulting in the indentation depth being greater than the thickness of the upper Ti _1-a Al _a N coating, or the test indenter penetrated through the multilayer Ti _1-a Al _a N/NbN unit nanometer In the case of a coating set, such that the measured hardness data falls outside the scope of the present invention, the coating shall be considered to still belong to the present invention.

In one of the embodiments, the Ti _1-a Al _a N/NbN unit nano-coating group contains cubic NbN and hexagonal NbN.

In one of the embodiments, the proportion of the cubic structure NbN is greater than or equal to 40%.

The interface between coatings with mixed crystal structure is obtained through process control, and the bonding force and toughness between coatings are improved. Innovatively applied the material mixed crystal strengthening mechanism to the design of the interface microstructure of the multi-layer coating. By designing the multi-layer Ti _1-a Al _a N/NbN unit nano-coating group to modulate the periodic structure, by improving the mixed crystal structure. The ratio of the total thickness of the unit nano-coating group at the interface to the total coating thickness increases the contribution of the mixed crystal strengthening effect to the overall performance of the coating.

In addition, through process control, the mixed crystal of cubic NbN and hexagonal NbN in the NbN coating layer is realized, and the intrinsic compressive stress of the coating is further enhanced by the mixed crystal strengthening effect, so as to achieve the ultimate goal of improving strength and wear resistance.

In one embodiment, the coating further includes a first zone coating, the first zone coating and the second zone coating are sequentially applied from the substrate outwards; the first zone coating is provided At least one layer, the first zone coating contains the following elements: at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Sr, Y, and C, At least one of N, O, and B.

In one embodiment, the thickness of the first region coating is 0.1-6 μm.

In one embodiment, the coating further includes a third zone coating, the second zone coating and the third zone coating are sequentially applied from the substrate outwards; the third zone coating is provided with at least one layer, the third zone coating contains the following elements: at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Sr, Y, and C, N, At least one of O and B.

In one embodiment, the thickness of each layer of the third region coating is 0.1-6 μm.

In one of the embodiments, the substrate contains or consists of the following materials: cemented carbide, cermet, ceramic, cubic boron nitride sintered body, diamond sintered body, and high-speed steel.

The manufacturing method of the cutting tool includes the following steps: (1) using a PVD method, depositing the first area coating on the surface of the substrate; (2) using the PVD method, on the first area coating, respectively depositing a layer of the Ti _1-a Al _a N nano-coating and a layer of the NbN nano-coating to form a group of Ti _1-a Al _a N/NbN unit nano-coatings, wherein 0.1≤a≤0.9 (3) Using PVD method, several groups of Ti _1-a Al _a N/NbN unit nano-coating groups are alternately deposited to form the second zone coating; (4) PVD method is adopted, in the first The third zone coating is deposited over the second zone coating.

In one embodiment, the thickness of the single-layer Ti _1-a Al _a N is 0.1-100 nm, the thickness of the single-layer NbN is 0.1-100 nm; the Ti _1-a Al _a N/NbN unit nano-coating layer The number of groups of groups is 1-100 groups.

The application of the cutting tool in cutting difficult-to-machine materials, the difficult-to-machine materials include titanium alloy, nickel-based alloy and heat-resistant stainless steel.

The present invention has the following beneficial effects:

1. The Ti _1-a Al _a N/NbN nano-multilayer coating of the multilayer structure of the present invention is introduced into the pure NbN coating of the prior art and has good high temperature oxidation resistance and toughness Ti _1-a Al _a N, the Ti _1-a Al _a N and NbN layers periodically alternate multi-layer superstructure, and under the action of the fine-grain strengthening superstructure mechanism, the toughness of the coating is enhanced, the bonding force is improved, and the friction and wear resistance and thermal resistance of the coating are improved. Stability, so that the performance of coating cutting performance is improved;

2. The present invention improves the properties such as hardness and wear resistance at high temperature by adjusting the monolayer thickness of the Ti _1-a Al _a N/NbN layer and the modulation period of the coating superstructure. Convenient operation, simple process, short preparation period, low cost, suitable for large-scale production;

3. The Ti _1-a Al _a N/NbN nano-multilayer coating prepared by the present invention has high hardness, high wear resistance and high temperature oxidation resistance, good coating adhesion and strong coating interface toughness. It can effectively resist the rapid expansion of cracks, which is beneficial to improve the service life of the tool.

Description of drawings

FIG. 1 is a schematic diagram of the cutting tool coating according to the first embodiment of the present invention.

Reference numerals: 1, first zone coating, 2, second zone coating, 2a, Ti _a Al _1-a N nanocoating, 2b, NbN nanocoating, 3, third zone coating, 4, base.

Detailed ways

The above content of the present invention will be further described in detail below through specific embodiments. However, it should not be construed that the scope of the above-mentioned subject matter of the present invention is limited only to the following examples. Without departing from the above technical idea of the present invention, various substitutions or changes made according to common technical knowledge in the art and conventional means should be included in the scope of the present invention.

The endpoints of ranges and any values disclosed herein are not limited to the precise ranges or values, which are to be understood to encompass values proximate to those ranges or values. For ranges of values, the endpoints of each range, the endpoints of each range and the individual point values, and the individual point values can be combined with each other to yield one or more new ranges of values that Ranges should be considered as specifically disclosed herein.

In the specification and claims of this patent, the terms "on", "coated on/on", "on/on" are used "Formed on", "deposited on/on", "covered on" and "provided on/on" means to form on a surface and/or Formed, deposited or provided in space, but not necessarily in contact with the surface. For example, applying a coating "on" a substrate does not preclude the presence of one or more other coatings of the same or different composition between the formed coating and the substrate. For example, the substrate itself may include conventional coatings such as those known in the art to which ceramic substrates are themselves coated.

Example 1

To manufacture a cutting tool, in this embodiment, the cutting tool is an indexable insert, which is prepared by the following steps:

A substrate 4 is provided in the reaction site, and in this embodiment, the substrate 4 is a cemented carbide.

FIG. 1 is a schematic diagram of a coating of a cemented carbide indexable insert manufactured in an embodiment of the present invention.

(1) The PVD method is used to deposit the first region coating 1 on the surface of the substrate 4; in this embodiment, the first region coating 1 is a Ti _1-a Al _a N coating, and the deposition thickness is 3 μm;

(2) Using the PVD method, deposit a layer of the Ti _1-a Al _a N nano-coating layer 2a and a layer of the NbN nano-coat layer on the coating layer 1 of the first region with an appropriate coating modulation cycle Layer 2b, forming a group of Ti _1-a Al _a N/NbN unit nano-coating group 2, where a=0.5; wherein, in this embodiment, the Ti _1-a Al _a N nano-coating 2a is coated on the NbN nano-coating layer. Under the layer 2b, but not limited to this embodiment, the Ti _1-a Al _a N nano-coating 2a and the NbN nano-coating 2b may be equal, for example, the NbN nano-coating 2b may be on the Ti _1-a Al _a under the N nanocoating 2a. As shown in FIG. 1 , only two unit nanocoating groups are shown, but not limited to this, and one unit nanocoating group or three or more unit nanocoating groups may also be used.

In this embodiment, the coating modulation period is 0.1 μm;

(3) adopting the PVD method, alternately depositing 2 groups of the Ti _1-a Al _a N/NbN unit nano-coating groups 2 to form the second zone coating;

(4) The PVD method is used to deposit the third-region coating 3 on the second-region coating. In this embodiment, the third-region coating 3 is a TiN colored coating.

The total thickness of the multi-layer coating of the cemented carbide indexable insert was measured to be 4 μm, the hardness of the coating was 36 GPa, and the NbN content of the cubic structure was 61%.

In this embodiment, the PVD method is used to deposit the coating, but it is not limited to this embodiment, and other deposition methods in the prior art may also be used to deposit the coating.

Comparative Example 1

The difference between the control example and the first example is that the coating is a Ti _0.5 Al _0.5 N coating deposited on the blade by the PVD method.

In terms of coating performance, the following is a comparison of cutting experiments between the insert of Comparative Example 1 and the PVD Ti _0.5 Al _0.5 N coated insert related to this application field through milling of heat-resistant stainless steel 0Cr23Ni13, wherein the deposition thickness of Ti _0.5 Al _0.5 N is 4 μm.

Operation: Face Milling

Workpiece: block piece

Material: heat-resistant stainless steel 0Cr23Ni13

Blade Type: RCMT 1606MOE-MR6

Cutting speed: 200m/min

Feed per tooth: 0.2mm/z

Cutting depth: 1mm

Cutting width: 60mm

wet cutting

The measurement results of the wear amount VB (in mm) after cutting for 2.2 minutes, 8.8 minutes, 15.4 minutes and 25.2 minutes are shown in Table 1 below:

Table 1 Wear amount after cutting for 2.2 minutes, 8.8 minutes, 15.4 minutes and 25.2 minutes

2.2min 8.8min 15.4min 25.2min Example 1 0.06 0.14 0.29 0.52 Comparative Example 1 0.16 0.41 0.82 --

The results show that under the same cutting conditions and cutting time, the wear amount of the blade prepared in Example 1 is significantly lower than that of the Ti _0.5 Al _0.5 N coated blade as Comparative Example 1, indicating that compared with the prior art Comparative Example 1, The invention greatly improves the service life of the blade coating.

Comparative Example Two

The difference between Comparative Example 2 and Example 1 is that the coating is NbN coating deposited on the blade by PVD method, wherein the deposition thickness of NbN coating is 4 μm.

The cutting conditions are as in Example 1

Table 2 Wear amount after cutting for 2.2 minutes, 8.8 minutes, 15.4 minutes and 25.2 minutes

2.2min 8.8min 15.4min 25.2min Example 1 0.06 0.14 0.29 0.52 Comparative Example Two 0.13 0.35 0.68 --

The results show that under the same cutting conditions, the wear amount of the blade prepared in Example 1 is significantly lower than that of the NbN-coated blade as a control example, indicating that compared with the comparison example 2, the present invention greatly improves the service life of the blade coating. .

Comparative Example Three

The difference between Comparative Example 3 and Example 1 is that the coating is a Ti _0.5 Al _0.5 N+NbN multilayer coating deposited on the blade by PVD method, the thickness of the Ti _0.5 Al _0.5 N layer is 3 μm, and the NbN layer is deposited The thickness is 1 μm.

The cutting conditions are as in Example 1

Table 3 Wear amount after cutting for 2.2 minutes, 8.8 minutes, 15.4 minutes and 25.2 minutes

2.2min 8.8min 15.4min 25.2min Example 1 0.06 0.14 0.29 0.52 Comparative Example Three 0.10 0.28 0.49 0.72

In Example 1, one layer of the Ti _1-a Al _a N nano-coating and one layer of the NbN nano-coating were used, while the Ti _0.5 Al _0.5 N+NbN multilayer coating in Comparative Example 3 did not reach the level of The nano-level of Example 1 shows that under the same cutting conditions and cutting time, the wear amount of the Ti _1-a Al _a N+NbN nano-coating blade prepared in Example 1 is significantly lower than that of Ti ₁ as Comparative Example 3. _-a Al _a N+NbN multi-layer coating blade, compared with the comparative example 3, the present invention greatly improves the service life of the blade coating.

The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features It is considered to be the range described in this specification.

The above examples only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (15)

1. a cutting tool comprising nano-multilayer coating, is characterized in that: comprise substrate and the coating that is coated on the substrate, and described coating comprises the second zone coating, and described second zone coating comprises at least A set of Ti _1-a Al _a N/NbN unit nano-coating groups formed by stacking a layer of Ti _1-a Al _a N nano-coating layer and a layer of NbN nano-coating layer, wherein 0.1≤a≤0.9. 2. The cutting tool according to claim 1, wherein: in the Ti _1-a Al _a N/NbN unit nano-coating group, the thickness of the Ti _1-a Al _a N nano-coating is 0.1-100nm , the thickness of the NbN nano-coating is 0.1-100 nm. 3. The cutting tool according to claim 2, characterized in that: in the Ti _1-a Al _a N/NbN unit nano-coating group, the sum of the thicknesses of single-layer Ti _1-a Al _a N and single-layer NbN 0.2-200nm. 4 . The cutting tool according to claim 3 , wherein the number of groups of the Ti _1-a Al _a N/NbN unit nano-coating groups is 1-100 groups. 5 . 5 . The cutting tool according to claim 4 , wherein the hardness of the Ti _1-a Al _a N/NbN unit nano-coating group is 25-45 GPa. 6 . 6 . The cutting tool according to claim 1 , wherein the Ti _1-a Al _a N/NbN unit nano-coating group contains cubic NbN and hexagonal NbN. 7 . 7 . The cutting tool according to claim 6 , wherein the proportion of the cubic structure NbN is ≥40%. 8 . 8. The cutting tool according to any one of claims 1-7, wherein the coating further comprises a first zone coating, and the first zone coating and the second zone coating are composed of a substrate Coating outwards in sequence; at least one layer of the first zone coating is provided, and the first zone coating contains the following elements: Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si , at least one of Sr, Y, and at least one of C, N, O, and B. 9 . The cutting tool according to claim 8 , wherein the thickness of the coating layer in the first region is 0.1-6 μm. 10 . 10. The cutting tool according to any one of claims 1-7, wherein the coating further comprises a third zone coating, and the second zone coating and the third zone coating are outward from the substrate Coating in sequence; at least one layer is provided for the third zone coating, and the third zone coating contains the following elements: Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Sr , at least one of Y, and at least one of C, N, O, and B. 11 . The cutting tool according to claim 10 , wherein the thickness of each layer of the third zone coating is 0.1-6 μm. 12 . 12. The cutting tool according to any one of claims 1-7, wherein the substrate contains or consists of the following materials: cemented carbide, cermet, ceramics, cubic boron nitride sintered body, diamond Sintered body and high speed steel. 13. The manufacturing method of the cutting tool according to any one of claims 1-12, characterized in that, comprising the steps of: (1) adopt PVD method, deposit described first area coating on the substrate surface; (2) adopting the PVD method, depositing a layer of the Ti _1-a Al _a N nano-coating and a layer of the NbN nano-coating on the first region coating to form a group of Ti _1-a Al _a N/NbN unit nano-coating group, wherein, 0.1≤a≤0.9; (3) adopting the PVD method, alternately depositing several groups of the Ti _1-a Al _a N/NbN unit nano-coating groups to form the second zone coating; (4) Using a PVD method, depositing the third zone coating on the second zone coating. The manufacturing method according to claim 13, characterized in that: the thickness of the single layer of Ti _1-a Al _a N is 0.1-100 nm, the thickness of the single layer of NbN is 0.1-100 nm; the thickness of the Ti _1-a The number of groups of Al _a N/NbN unit nano-coating groups is 1-100 groups. 15. The application of the cutting tool according to any one of claims 1 to 12 in cutting difficult-to-machine materials, wherein the difficult-to-machine materials include titanium alloys, nickel-based alloys and heat-resistant stainless steel.

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