Method for improving intermittent cutting performance of Ti (C, N)-based metal ceramic cutter and cutter

Abstract

The invention discloses a method for improving the intermittent cutting performance of a Ti (C, N)-based metal ceramic cutter and the cutter, an AlTiN transition layer and an AlTiN / AlCrN wear-resistant layer are sequentially deposited on a Ti (C, N)-based metal ceramic matrix through physical vapor deposition, the AlTiN transition layer and the metal ceramic matrix are regulated and controlled to form a coherent / semi-coherent interface, the coating-matrix bonding strength is improved, the cutting performance of the Ti (C, N)-based metal ceramic cutter is improved, and the cutting performance of the Ti (C, N)-based metal ceramic cutter is improved. Meanwhile, a gradient structure system which is gradually transited from a high-hardness bottom layer dominated by the AlTiN layer to a tough surface layer enriched by the AlCrN layer is constructed on the nanoscale, a coherent / semi-coherent structure is formed at an adjacent AlTiN / AlCrN interface by accurately controlling the lattice matching degree between nano layers, the hardness of the nano multi-unit is improved, meanwhile, stress release is achieved by means of a dislocation slippage mechanism, and the mechanical property of the nano multi-unit is improved. The problems that the performance stability between a Ti (C, N)-based metal ceramic matrix and an AlCrN / AlTiN coating is poor, the service life of intermittent cutting is short, and the impact resistance is poor are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coated cutting tools, and more particularly, relates to a method for improving the intermittent cutting performance of a Ti(C,N)-based metal ceramic cutting tool and a cutting tool. Background Art

[0002] Ti(C,N)-based cermets are composite materials composed of a Ti(C,N) hard phase and a metal binder phase. Compared to traditional WC-Co-based carbide tools, Ti(C,N)-based cermets offer high hardness, excellent wear resistance, and resistance to high-temperature deformation, effectively improving the surface finish and dimensional accuracy of workpieces. As modern manufacturing rapidly develops toward high-speed, high-efficiency, and high-precision manufacturing, Ti(C,N)-based cermet tools are susceptible to crack propagation or breakage during use when machining high-strength materials due to their high brittleness. This limits their application in certain high-load, high-impact environments. Furthermore, under high-temperature service conditions, the metal binder phase is prone to softening, resulting in a decrease in tool hardness, toughness, and wear resistance, accelerating tool wear and failure. Therefore, it is necessary to improve the toughness, wear resistance, and impact resistance of Ti(C,N)-based cermet tools to meet higher demands.

[0003] To address the challenges of increased wear, shortened tool life, and unstable machining quality faced by cutting tools when machining high-strength materials, surface coating technology is currently considered a key development direction for improving the performance of metal-ceramic cutting tools. This involves depositing a thin film of ultra-hard, high-temperature-resistant material at the micron to nanometer scale onto the tool substrate, providing strong support. The coating also provides wear and corrosion resistance, and reduces friction. Therefore, coatings are often applied to tool substrates to enhance tool performance. However, designing the coating and maintaining a stable bond between the coating and the tool substrate are key to improving tool performance.

[0004] Nano-multilayer coatings are formed by alternating deposition of two materials with different compositions or structures. This can combine the performance advantages of different materials and is an effective way to improve coating performance. CN 113930722 A, a high-red-hardness AlCrN / AlTiN nano-multilayer coating and its preparation method, discloses the use of AlCr and AlTi alloys as target materials to prepare an AlCrN / AlTiN nano-multilayer coating with a coherent relationship. This nano-multilayer coating is composed of alternating AlCrN layers and AlTiN layers. Both the AlCrN and AlTiN layers have a face-centered cubic structure and maintain a coherent relationship. The single layers of the AlCrN and AlTiN layers are both nanometer-sized in thickness. At high temperatures, the AlCrN coating can form a stable oxide film composed mainly of Al2O3 on its surface, which hinders the diffusion of external oxygen elements into the coating, reduces the oxidation rate, and has excellent high-temperature oxidation resistance. The AlTiN coating is relatively stable during high-temperature annealing and has excellent red hardness. The patent proposes an AlCrN / AlTiN nano-multilayer coating with a coherent relationship. It also utilizes the coherent interface between the nanolayers to hinder the coating's phase transition and element diffusion, further enhancing the coating's hardness, wear resistance, and high-temperature oxidation resistance, improving the coating's overall performance. However, due to significant differences in physical and chemical properties between the Ti(C,N)-based cermet and the AlCrN / AlTiN nano-multilayer coating, such as differences in thermal expansion coefficient, hardness, and elastic modulus, the AlTi metal layer's thermal expansion coefficient and elastic modulus differ significantly from those of the Ti(C,N)-based cermet, leading to interfacial stress concentration. Furthermore, due to the metal layer's low hardness, it cannot provide strong support for the AlTiN / AlCrN wear-resistant layer above it, preventing the AlTiN / AlCrN coating from fully utilizing its wear resistance. Furthermore, due to the AlTi metal layer's low hardness and poor strength, it is more likely to fracture when subjected to transverse shear stress, causing the entire coating to flake off and fail. The poor performance stability between the Ti(C,N)-based cermet substrate and the AlCrN / AlTiN coating leads to a short intermittent cutting service life, limiting its application in certain high-load, high-impact environments. Summary of the Invention

[0005] The present invention provides a method for improving the intermittent cutting performance of Ti(C,N)-based cermet tools in order to overcome the problems of insufficient toughness and impact resistance and easy crack propagation or breakage when the existing Ti(C,N)-based cermets use AlCrN / AlTiN nano multilayer coatings.

[0006] Another technical problem of the present invention is a Ti(C,N) based metal ceramic tool obtained by this method.

[0007] The present invention is achieved through the following technical solutions:

[0008] A method for improving the intermittent cutting performance of a Ti(C,N)-based cermet tool, comprising:

[0009] S1. The Ti(C,N)-based cermet is subjected to surface sandblasting and ultrasonic cleaning;

[0010] S2. Heating and etching the cleaned Ti(C, N)-based cermet;

[0011] S3. Depositing a 0.2-1.0 μm AlTiN transition layer on the etched Ti(C,N)-based cermet surface, where the AlTiN forms a coherent or semi-coherent interface with the Ti(C,N) surface;

[0012] S4. Depositing an AlTiN / AlCrN wear-resistant layer with a thickness of 0.5 to 4.0 μm on the AlTiN transition layer, in which AlTiN and AlCrN are alternately arranged and the contents of AlTiN and AlCrN vary gradually.

[0013] Furthermore, the sand used in the sandblasting treatment has a diameter range of 20 to 50 μm, the spray gun pressure is controlled at 0.2 to 1.0 MPa, and the water-to-sand ratio is 15 to 45%. Sandblasting can improve surface morphology and enhance the adhesion of the transition layer. If the sand grains are fine and the spray gun pressure is too low, the surface of the treated metal-ceramic substrate will be too smooth, making it difficult for the coating to fully adhere, reducing the bonding strength and making it easy to peel off. If the sand grains are coarse and the spray gun pressure is too high, a large amount of the binding phase in the metal-ceramic aggregate may be removed, destroying the bonding strength of the surface hard phase, thereby damaging the substrate, reducing surface integrity, and affecting the thickness and quality of the coating.

[0014] Furthermore, the heating etching is specifically as follows: heating and vacuuming, the vacuum degree is not less than 5×10 -2 Pa, after the temperature rises to 350-600 ° C, inert gas is introduced to etch and clean the sample.

[0015] Furthermore, the bias voltage during etching is maintained at -200 to -600 V, the etching time is 10 to 45 minutes, and the ion source current is 150 to 250 A.

[0016] Furthermore, the AlTiN transition layer is deposited by adjusting the bias voltage to -60 to -20 V, introducing N2 gas, adjusting the gas pressure to 1.0 to 4.0 Pa, and the current density of the AlTi target to 85 to 120 A / cm 2 , deposit the AlTiN transition layer for 10 to 30 minutes.

[0017] Furthermore, the AlTiN / AlCrN wear-resistant layer includes no less than one AlTiN / AlCrN sublayer, and the AlTiN / AlCrN sublayer includes an alternating unit composed of multiple AlTiN and AlCrN nano-monolayers. The sum of the thickness of the AlTiN layer and the AlCrN layer in each alternating unit (i.e., the modulation period) is 5 to 50 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer in each alternating unit is 3:1 to 1:3. The proportion of AlCrN in the wear-resistant layer gradually increases from the inside to the outside, and the layer thickness gradually decreases, forming a nano-gradient structure. Between different levels, the thickness ratio of AlTiN / AlCrN changes, so that the high proportion of AlTiN in the inner layer maintains high hardness and improves wear resistance, and the high proportion of AlCrN in the outer layer increases toughness and enhances impact resistance.

[0018] Furthermore, as the AlTiN transition layer moves outward, the combined thickness of the alternating units decreases, while the proportion of AlCrN in the alternating units increases. The thicker inner layer reduces the stress gradient between the substrate and the coating, while the gradually thinner outer layer maintains the coating's high hardness and toughness, improving its impact resistance.

[0019] Furthermore, the AlTiN / AlCrN wear-resistant layer is deposited as follows: the bias voltage is adjusted to -100 to -80 V, the substrate support rotation speed is 1 to 1.5 r / min, and the current density of the AlTi target is 80 to 120 A / cm 2 , the current density of AlCr target is 80~120A / cm 2 , the deposition time is 25min~120min.

[0020] Furthermore, the atomic percentages of each element in the AlTiN transition layer are: Al: 15-30 at.%, Ti: 15-25 at.%, N: 45-55 at.%; the atomic percentages of each element in the AlTiN / AlCrN wear-resistant layer are: Al: 15-30 at.%, Ti: 15-25 at.%, N: 45-55 at.% in the AlTiN layer; Al: 15-25 at.%, Cr: 15-30 at.%, N: 45-55 at.% in the AlCrN layer.

[0021] A Ti(C, N)-based metal ceramic cutting tool is prepared by the above method.

[0022] Compared with the prior art, the beneficial effects are:

[0023] The present invention adopts an AlTiN coating as a transition layer. On the one hand, the good mechanical properties of AlTiN are utilized to provide good support for the AlTiN / AlCrN deposited thereon. On the other hand, the lattice constants of AlTiN and Ti(C,N) in the cermet are similar. By controlling the composition of the AlTiN transition layer and the deposition parameters, a coherent or semi-coherent interface is formed between the AlTiN and the Ti(C,N) grains in the cermet, thereby alleviating stress concentration at the film-substrate interface and further reducing the difference in physical and chemical properties (thermal expansion coefficient, hardness, elastic modulus) between the coating and the cermet substrate, thereby effectively increasing the coating bonding strength.

[0024] The present invention uses AlTiN / AlCrN as a wear-resistant layer. By adopting a gradient variation in element content and organizational structure coupled with a multilayer structure, a gradient structural system is constructed at the nanoscale, with a high-hardness bottom layer dominated by the AlTiN layer gradually transitioning to a tough surface layer enriched in the AlCrN layer. By precisely controlling the lattice matching between nanolayers, a coherent / semi-coherent structure is formed at the adjacent AlTiN / AlCrN interface, thereby improving the hardness of the nano-multi-unit. Compared to the traditional coherent interface coating where dislocations are completely suppressed, the present invention precisely controls the dislocation slip at the interlayer interface (microscopic level) and the crack propagation path within the coating (macroscopic level) through the coherent / semi-coherent interface and stress gradient design. This allows the coating to release some stress under high impact conditions by means of the dislocation slip mechanism without premature fracture or peeling, thereby maintaining high hardness while improving toughness and fracture resistance. The gradual increase in the AlCrN ratio from the inside out of the gradient multilayer structure gives the coating stronger oxidation resistance in high-temperature environments, mitigating the effects of oxygen diffusion on coating performance. It also maximizes the age-hardening effect of the AlTiN-rich nano-layered units at the bottom, thereby improving wear resistance and thermal stability. This structure effectively alleviates the brittleness of Ti(C,N)-based cermet tools caused by high-hardness coatings. While maintaining the coating's excellent wear resistance, it significantly enhances its toughness and impact resistance, thereby extending tool life and improving machining stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the Ti(C,N) based metal ceramic coating tool in the present invention.

[0026] Figure 2 These are the Rockwell indentation diagrams of the metal ceramics after coating in Example 1 and Comparative Example 2 of the present invention.

[0027] Figure 3 The hardness, elastic modulus and H of the metal ceramics after coating and without coating in Example 1 and Comparative Example 1 of the present invention are shown in FIG. 3 / E 2 value.

[0028] Figure 4 The fracture toughness of the coated metal ceramics and the uncoated metal ceramics in Example 1 and Comparative Example 1 of the present invention.

[0029] Figure 5 The figure shows the lifespan comparison of the intermittent machining of the coated cermet and the uncoated cermet tools in Example 1 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0030] The present invention will be further explained and illustrated below with reference to the examples, but the specific examples do not limit the present invention in any form. Unless otherwise specified, the methods and equipment used in the examples are conventional methods and equipment in the art, and the raw materials used are all conventional commercially available raw materials.

[0031] Example 1

[0032] The present invention provides a Ti(C,N)-based cermet tool with a 0.5μm-thick AlTiN transition layer and a 1.5μm-thick AlTiN / AlCrN wear-resistant layer coated on the tool substrate. A thin transition layer hinders grain growth in the AlTiN coating and may prevent the formation of a continuous and stable coherent / semi-coherent interface, resulting in insufficient bonding and shortening the coating's lifespan. A thicker transition layer, on the other hand, can cause excessive internal stress in the coating. Therefore, an AlTiN transition layer thickness between 0.2 and 1.0μm optimizes interfacial bonding and alleviates internal stress, thereby improving the overall coating's durability and toughness. Among them, the thickness of the first AlTiN / AlCrN sublayer is 0.5μm, the thickness of the second AlTiN / AlCrN sublayer is 0.5μm, and the thickness of the third AlTiN / AlCrN sublayer is 0.5μm. The atomic percentages of each element in the AlTiN layer in the transition layer and the wear-resistant layer are: Al: 29at.%, Ti: 21at.%, N: 50at.%; the atomic percentages of each element in the AlCrN in the wear-resistant layer are: Al: 30at.%, Cr: 20at.%, N: 50at.%.

[0033] The total thickness of the alternating units in the first AlTiN / AlCrN sublayer of the AlTiN / AlCrN wear-resistant layer is 50 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer is 3:2. The total thickness of the alternating units in the second AlTiN / AlCrN sublayer is 25 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer is 1:1. The total thickness of the alternating units in the third AlTiN / AlCrN sublayer is 12.5 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer is 2:3.

[0034] The preparation steps are:

[0035] S1. Sandblast the cermet sample using 20 μm diameter alumina sand at a water-to-sand ratio of 35% and a spray gun pressure of 0.5 MPa. The sample is then ultrasonically cleaned to remove residual material and rinsed in deionized water. After sandblasting to increase surface roughness and remove surface contaminants to ensure good coating adhesion, the workpiece is then dried at 80°C under vacuum or an inert atmosphere.

[0036] S2. The treated Ti(C,N)-based cermet sample was clamped on the workpiece holder of the coating equipment, heated and vacuumed, and the vacuum degree was 5×10 -2 Pa, and after the temperature was raised to 550 ° C, Ar gas was introduced to etch the sample to remove surface oxides and enhance surface activity. The workpiece mounting bias was maintained at -450 V, the etching time was 25 min, and the ion source current was 200 A.

[0037] S3. Adjust the bias voltage to -60V, introduce N2 gas, adjust the pressure to 3.0Pa, and the current density of the AlTi target to 100A / cm 2 , the AlTiN transition layer was deposited for 30 min, so that the AlTiN layer formed a coherent or semi-coherent interface with the Ti(C,N) surface, enhancing the bonding strength of the coating.

[0038] S4. Adjust the bias voltage to -100 V, rotate the substrate holder at 1 r / min, and deposit the first AlTiN / AlCrN sublayer. The current density of the AlTi target is 120 A / cm 2 , the current density of AlCr target is 80A / cm 2 The deposition time is 25 min. Then the substrate support rotation speed is adjusted to 2 r / min, and the second layer of AlTiN / AlCrN sublayer is deposited. The current density of the AlTi target is 100 A / cm 2 , the current density of AlCr target is 100A / cm 2 , the deposition time is 25min. Finally, the substrate support rotation speed is adjusted to 4r / min, and the third layer of AlTiN / AlCrN sublayer is deposited. The current density of the AlTi target is 80A / cm 2 , the current density of AlCr target is 120A / cm 2 After the deposition is complete, the vacuum chamber temperature is lowered to room temperature, and the sample is removed from the vacuum chamber to obtain a metal ceramic sample coated with a 0.5 μm thick AlTiN transition layer and a 1.5 μm thick AlTiN / AlCrN wear-resistant layer.

[0039] Example 2

[0040] The present invention provides a Ti(C,N)-based cermet cutting tool. The cermet sample comprises a 0.3μm-thick AlTiN transition layer and a 2.5μm-thick AlTiN / AlCrN wear-resistant layer coated on the tool substrate. The first AlTiN / AlCrN sublayer is 1μm thick, and the second AlTiN / AlCrN sublayer is 1.5μm thick. The atomic percentages of the elements in the transition and wear-resistant layers of the AlTiN layer are: Al: 25 at.%, Ti: 20 at.%, and N: 55 at.%, while the atomic percentages of the elements in the AlCrN wear-resistant layer are: Al: 28 at.%, Cr: 25 at.%, and N: 47 at.%.

[0041] The total thickness of a single alternating unit in the first AlTiN / AlCrN sublayer of the AlTiN / AlCrN wear-resistant layer is 30 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer is 1:1; the total thickness of a single alternating unit in the second AlTiN / AlCrN sublayer is 12 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer is 2:3.

[0042] The preparation steps are:

[0043] S1. Sandblast the cermet sample using 35 μm diameter alumina sand at a 20% water-to-sand ratio and a spray gun pressure of 0.7 MPa. The cermet sample is then ultrasonically cleaned to remove residual material and rinsed in deionized water. After cleaning, the workpiece is dried at 100°C under vacuum or an inert atmosphere.

[0044] S2. Clamp the cleaned Ti(C,N)-based cermet sample on the workpiece holder of the coating equipment, heat and evacuate until the vacuum degree reaches 1×10 -2 Pa, and after the temperature is raised to 500 ° C, Ar gas is introduced to etch and clean the sample. The workpiece mounting bias is maintained at -600 V, the etching time is 10 min, and the ion source current is 250 A.

[0045] S3. Adjust the bias voltage to -60V, introduce N2 gas, adjust the pressure to 4.0Pa, and the current density of the AlTi target to 85A / cm 2 , deposit AlTiN transition layer for 30 minutes.

[0046] S4. Adjust the bias voltage to -100 V, set the substrate support rotation speed to 1.5 r / min, and deposit the first AlTiN / AlCrN sublayer. The current density of the AlTi target is 85 A / cm 2 , the current density of AlCr target is 90A / cm 2 , the deposition time was 50 min; then, the current density of the AlTi target was adjusted to 85 A / cm 2, the current density of AlCr target is 110A / cm 2 The substrate support rotation speed was set to 4 rpm, and the deposition time was 50 minutes. After the deposition was completed, the vacuum chamber temperature was cooled to room temperature, and the sample was removed from the vacuum chamber to obtain a metal ceramic sample coated with a 0.3 μm thick AlTiN transition layer and a 2.5 μm thick AlTiN / AlCrN wear-resistant layer.

[0047] Example 3

[0048] The present invention provides a Ti(C,N)-based cermet cutting tool. The cermet sample comprises a 0.2μm-thick AlTiN transition layer and a 1.0μm-thick AlTiN / AlCrN wear-resistant layer coated on the tool substrate. The first AlTiN / AlCrN sublayer is 0.3μm thick, and the second AlTiN / AlCrN sublayer is 0.7μm thick. The atomic percentages of the elements in the transition and wear-resistant layers of the AlTiN layer are: 25 at.%, 30 at.%, and 45 at.%, respectively. The atomic percentages of the elements in the AlCrN layer of the wear-resistant layer are: 23 at.%, 25 at.%, and 52 at.%.

[0049] The total thickness of a single alternating unit in the first AlTiN / AlCrN sublayer of the AlTiN / AlCrN wear-resistant layer is 50 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer is 3:1; the total thickness of a single alternating unit in the second AlTiN / AlCrN sublayer is 20 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer is 1:1.

[0050] The preparation steps are:

[0051] S1. Sandblast the cermet sample using 50 μm diameter alumina sand at a water-to-sand ratio of 15% and a spray gun pressure of 1.0 MPa. The cermet sample is then ultrasonically cleaned to remove residual material and rinsed in deionized water. After cleaning, the workpiece is dried at 120°C under vacuum or an inert atmosphere.

[0052] S2. The cleaned Ti(C,N)-based cermet sample was clamped on the workpiece holder of the coating equipment, heated and vacuumed, and the vacuum degree was 8×10 -3 Pa, and after the temperature rises to 450 ° C, Ar gas is introduced to etch and clean the sample. The workpiece mounting bias is maintained at -200 V, the etching time is 30 min, and the ion source current is 250 A.

[0053] S3. Adjust the bias voltage to -20V, introduce N2 gas, adjust the pressure to 1.0Pa, and the current density of the AlTi target to 120A / cm 2, deposit AlTiN transition layer for 10 minutes.

[0054] S4. Adjust the bias voltage to -80V and the current density of the AlTi target to 120A / cm 2 , the current density of AlCr target is 80A / cm 2 , the deposition time was 30 min, and then the current density of the AlTi target was adjusted to 100 A / cm 2 , the current density of AlCr target is 100A / cm 2 The substrate support rotation speed is set to 4r / min, and the deposition time is 60min. After the deposition is completed, the vacuum chamber temperature is cooled to room temperature, and the sample is taken out after opening the vacuum chamber.

[0055] Comparative Example 1

[0056] This comparative example used the same AlTiN transition layer as in Example 1. The bias voltage was then adjusted to -100 V, the substrate support rotation speed was set at 1 r / min, and an AlTiN / AlCrN coating was prepared using the deposition parameters for the first AlTiN / AlCrN sublayer in Example 1. The deposition time was 80 minutes. The resulting coating consisted of a 0.5 μm AlTiN transition layer and a 1.5 μm AlTiN / AlCrN wear-resistant layer. The difference was that the thickness of the individual alternating units in the AlTiN / AlCrN wear-resistant layer and the thickness ratio of the AlTiN layer to the AlCrN layer were kept constant in this comparative example.

[0057] Comparative Example 2

[0058] In this comparative example, the deposition parameters of the AlTiN / AlCrN wear-resistant layer in Example 1 are used to deposit a 2.0 μm thick AlTiN / AlCrN wear-resistant layer on the metal ceramic. The difference is that in this comparative example, only the AlTiN / AlCrN wear-resistant layer is deposited on the metal ceramic surface, and there is no AlTiN transition layer.

[0059] The bonding strength between the coating and the substrate was evaluated using the indentation method described in JB / T 13683-2020. The maximum load of the Rockwell hardness tester was set to 60 kg, the holding time was 5 s, and the indenter used was a diamond indenter with a cone angle of 120° and a top spherical radius of 0.2 mm. Figure 2 It can be found that in Example 1, the coating is well bonded to the metal ceramic substrate. Only four obvious long cracks and two small cracks are observed around the indentation of the coating, and no obvious peeling is found. In Comparative Example 2, when the AlTiN transition layer is removed and the AlTiN / AlCrN wear-resistant layer is deposited directly on the metal ceramic substrate, the bonding between the coating and the substrate is poor, and obvious peeling of the coating occurs.

[0060] like Figure 3As shown in FIG, the hardness of the uncoated Ti(C, N)-based cermet is 27.4±1.7 GPa, and the hardness of the coatings in Comparative Example 1 and Example 1 are 37.2±0.8 GPa and 36.1±1.0 GPa, respectively. 3 / E 2 The H value is 0.079±0.010GPa, while the H value of the coatings in Comparative Example 1 and Example 1 is 3 / E 2 The values are 0.182±0.008GPa and 0.170±0.012GPa, respectively, indicating that the coating composed of multiple AlTiN / AlCrN sublayers with different sums of thicknesses and thickness ratios in Example 1 can significantly improve the plastic deformation resistance of Ti(C,N)-based metal ceramics after being coated on the surface of Ti(C,N)-based metal ceramics.

[0061] The fracture toughness of Ti(C,N) cermets before and after coating was tested according to the method described in JB / T 12616-2016. Figure 4 The results show that the fracture toughness of the uncoated Ti(C,N) cermet is 9.8±0.18MPa·m 1 / 2 The fracture toughness of the metal ceramics coated in Comparative Example 1 increased to 10.8±0.05MPa·m 1 / 2 , while the fracture toughness of the metal ceramic in Example 1 is further improved, reaching 11.3±0.07MPa·m 1 / 2 .

[0062] The dry turning test was carried out using TNMG160404R-TVF type Ti(C,N) based cermet inserts. 45# steel round bar, where four rectangular grooves with a width of 5mm and a depth of 100mm are evenly distributed on the processed round bar, the intermittent processing capability of the coating is evaluated by turning the outer circle. During the cutting process, the linear speed V c The feed rate Fz is 0.2mm / r, and the cutting depth A p According to the international standard ISO3685, the tool flank wear is measured using an optical microscope. When the maximum wear width of the flank reaches 300μm or the tool tip is chipped, the tool is considered to have failed. Figure 5 As shown, the tip of the uncoated metal ceramic tool broke after 12 minutes of machining, the tool with AlTiN coating in comparative example 1 failed after 15 minutes of machining, and the life of the metal ceramic tool after coating in example 1 can reach 21 minutes, which greatly improves the performance in intermittent machining.

[0063] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for improving the intermittent cutting performance of Ti(C,N) based cermet cutting tools, characterized in that the steps include: S1. The Ti(C,N)-based cermet is subjected to surface sandblasting and ultrasonic cleaning; S2. Heating and etching the cleaned Ti(C, N)-based cermet; S3. Deposit a 0.2-1.0 μm AlTiN transition layer on the etched Ti(C,N)-based cermet surface. AlTiN forms a coherent or semi-coherent interface with the Ti(C,N) surface; S4. Depositing an AlTiN / AlCrN wear-resistant layer with a thickness of 0.5 to 4.0 μm on the AlTiN transition layer, in which AlTiN and AlCrN are alternately arranged and the contents of AlTiN and AlCrN vary gradually.

2. The method for improving the interrupted cutting performance of Ti(C,N)-based cermet tools according to claim 1, characterized in that: The diameter of the sand used in the sand blasting process ranges from 20 to 50 μm, the pressure of the spray gun is controlled at 0.2 to 1.0 MPa, and the water-sand ratio is 15 to 45%.

3. The method for improving the interrupted cutting performance of Ti(C,N)-based cermet tools according to claim 1, characterized in that: The heating etching specifically includes: heating and vacuuming, with a vacuum degree of not less than 5×10 -2 Pa, after the temperature rises to 350-600 °C, inert gas is introduced to etch and clean the sample.

4. The method for improving the interrupted cutting performance of Ti(C,N)-based cermet tools according to claim 1, characterized in that: The bias voltage during etching is maintained at -200 to -600 V, the etching time is 10 to 45 minutes, and the ion source current is 150 to 250 A.

5. The method for improving the interrupted cutting performance of Ti(C,N)-based cermet tools according to claim 1, characterized in that: The deposition of the AlTiN transition layer is as follows: the bias voltage is adjusted to -60 to -20 V, N2 gas is introduced, the gas pressure is adjusted to 1.0 to 4.0 Pa, and the current density of the AlTi target is 85 to 120 A / cm 2 , deposit the AlTiN transition layer for 10 to 30 minutes.

6. The method for improving the interrupted cutting performance of Ti(C,N)-based cermet tools according to claim 1, characterized in that: The AlTiN / AlCrN wear-resistant layer includes at least one AlTiN / AlCrN sublayer, and the AlTiN / AlCrN sublayer includes alternating units composed of multiple AlTiN and AlCrN nano-monolayers. The total thickness of the AlTiN layer and the AlCrN layer in each alternating unit is 5 to 50 nm, and the thickness ratio of the AlTiN layer to the AlCrN layer in each alternating unit is 3:1 to 1:

3.

7. The method for improving the interrupted cutting performance of Ti(C,N)-based cermet tools according to claim 6, characterized in that: In the outward direction of the AlTiN transition layer, the sum of the thicknesses of the alternating units gradually decreases, and the proportion of AlCrN in the alternating units gradually increases.

8. The method for improving the interrupted cutting performance of Ti(C,N)-based cermet tools according to claim 7, characterized in that: The deposition of AlTiN / AlCrN wear-resistant layer is as follows: the bias voltage is adjusted to -100~-80V, the substrate support rotation speed is 1~1.5r / min, and the current density of AlTi target is 80~120A / cm 2 , the current density of AlCr target is 80~120A / cm 2 , the deposition time is 25min~120min.

9. The method for improving the interrupted cutting performance of Ti(C,N)-based cermet tools according to claim 1, characterized in that: The atomic percentages of the elements in the AlTiN transition layer are: Al: 15-30 at.%, Ti: 15-25 at.%, N: 45-55 at.%; the atomic percentages of the elements in the AlTiN / AlCrN wear-resistant layer are: Al: 15-30 at.%, Ti: 15-25 at.%, N: 45-55 at.% in the AlTiN layer; Al: 15-25 at.%, Cr: 15-30 at.%, N: 45-55 at.% in the AlCrN layer.

10. A Ti(C,N)-based metal ceramic tool, characterized in that: A Ti(C,N)-based cermet tool prepared by the method according to any one of claims 1 to 9.

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