Cutting edges for engineering machinery and their manufacturing process

Abstract

This invention discloses a cutting edge for engineering machinery and its manufacturing process, belonging to the field of cutting edge technology. The technical solution involves sequentially depositing a surface carburizing diffusion layer, a Zr transition layer, and a ZrNbSiB boride gradient coating on the surface of the cutting edge substrate from the inside out. This invention combines boride coating, PVD method, and carburizing technology. The workpiece surface is first carburized by ion sputtering, and then a Zr transition layer is deposited by ion plating, followed by magnetron sputtering to prepare a ZrNbSiB boride gradient coating with a compositional gradient. This mitigates the difference in physical properties between the coating and the substrate material, increases the hardness of the substrate material, enhances the adhesion between the coating and the substrate, improves the matching performance of structure and performance, and effectively improves surface treatment efficiency and workpiece service life.

Description

Technical Field

[0001] This invention relates to the field of cutting edge technology, specifically to a cutting edge for engineering machinery and its manufacturing process. Background Technology

[0002] The blade edge is the most stress-bearing working part of bulldozers, loaders, and other construction machinery blades during operation. However, traditional construction machinery blade edges cannot meet the harsh working conditions required by bulldozers, and the special alloy steel materials such as 31Si2CrMoB used are expensive, and their service life still falls short of expectations. This also reduces the overall working efficiency of bulldozers and other construction machinery, and increases daily maintenance and upkeep costs. Therefore, developing new construction machinery blade edges and their manufacturing processes has significant practical and application value.

[0003] Because boride coatings possess excellent properties such as high hardness, high strength, chemical stability, heat resistance, and wear resistance, it is expected that the wear resistance of parts can be improved by preparing boride coatings on the surface of parts or by carbonizing the metal surface.

[0004] Currently, the main technologies for preparing boride coatings include spraying and vapor deposition. Spraying involves applying coating material to the surface of a workpiece using pressure or centrifugal force. While this method offers high efficiency, the adhesion between the coating and the substrate is poor, and the surface is very rough, making it unsuitable for harsh operating conditions requiring high pressure and speed. Vapor deposition, especially physical vapor deposition (PVD), produces coatings with extremely high hardness, strength, thermal stability, and wear resistance. Furthermore, the process temperature can be controlled below 400℃, preventing changes in the substrate structure and maintaining surface dimensions and shape accuracy. Therefore, PVD holds great potential in surface treatment. However, directly applying PVD boride coatings to bulldozer parts can lead to premature detachment and failure due to significant differences in hardness, elastic modulus, and coefficient of thermal expansion between the substrate and the coating material.

[0005] Chinese invention patent CN101058870A discloses a Hall-source-excited magnetron sputtering enhanced magnetic filtering multi-arc ion composite coating method. A single PVD coating is used on the mold surface. Poor adhesion between the coating and the substrate, as well as poor mechanical matching between the PVD coating and the substrate, are significant factors limiting the high hardness and low coefficient of friction advantages of the PVD coating. Chinese invention patent CN103727180A discloses a planetary gear mechanism with a wear-resistant coating. It directly prepares a wear-resistant ceramic coating and a diamond coating on the carbon steel surface. Due to the relatively soft substrate's insufficient hardness to support the coating and the significant performance differences between the substrate and the coating, the prepared coating's performance fails to meet many practical application requirements, especially under high-speed, heavy-load, and alternating load conditions, the coating quickly peels off and wears. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide an engineering machinery cutting edge and its preparation process. This involves combining boride coating, PVD method, and carburizing technology to prepare a surface carburizing diffusion layer between the carbide coating and the workpiece substrate using ion sputtering. Specifically, the workpiece surface is first carburized by ion sputtering, and then a Zr transition layer is deposited on the surface using ion plating, followed by magnetron sputtering to prepare a ZrNbSiB boride gradient coating with a compositional gradient. This mitigates the difference in physical properties between the coating and the substrate material, increases the hardness of the substrate material, enhances the adhesion between the coating and the substrate, improves the matching performance of structure and performance, and effectively improves surface treatment efficiency and workpiece service life.

[0007] The technical solution of this invention is as follows:

[0008] On the one hand, the present invention provides a manufacturing process for a cutting edge of engineering machinery, wherein a surface carburizing diffusion layer, a Zr transition layer and a ZrNbSiB boride gradient coating are sequentially disposed on the surface of the cutting edge substrate from the inside to the outside.

[0009] Preferably, the blade corner substrate is rolled, quenched, and tempered at high temperature, and then surface carburized by ion plating to form a surface carburized diffusion layer; then a Zr transition layer is deposited by ion plating and a ZrNbSiB boride gradient coating is prepared by magnetron sputtering.

[0010] Preferably, the manufacturing process of the cutting edge of the engineering machinery of the present invention specifically includes the following steps:

[0011] S1 cutting edge machining: rolling;

[0012] S2 blade corner heat treatment: Quenching → High temperature tempering;

[0013] S3 blade corner surface treatment: Immerse the blade corner in alcohol and acetone sequentially, and ultrasonically clean for 50-60 minutes each to remove surface impurities and other adhering substances. After thorough drying, quickly place it in a PVD composite coating machine and vacuum it to 6.0-6.5×10⁻⁶. -3 Pa, heat to 300-320℃, and hold for 40-50 minutes;

[0014] S4 blade corner surface glow discharge cleaning: Ar gas is introduced at a pressure of 1.7-2 Pa and a temperature of 260-285℃. The bias power supply voltage is 550-650V with a duty cycle of 0.2-0.4. The surface glow discharge cleaning is performed for 30-40 minutes.

[0015] S5 blade corner surface ion cleaning: adjust the bias voltage to 450-500V, duty cycle 0.3-0.4, Ar gas pressure 1-1.3Pa, temperature 240-260℃, turn on the ion source, ion cleaning for 10-20min, turn on the two C target power supplies, C target current 110-120A, ion bombardment for 3-5min.

[0016] S6 blade corner ion plating and carburizing: C target ion plating power supply is adjusted to 100-105A, Ar gas pressure is 1.3-1.7Pa, substrate bias voltage is adjusted to 370-400V, temperature is 230-260℃, and ion carburizing is performed for 25-35min.

[0017] S7 ion plating deposition of Zr transition layer: Ar gas pressure is adjusted to 1-1.1 Pa, bias voltage drop is 320-350 V, deposition temperature is 220-250 ℃, C target current is turned off, Zr target ion plating current is turned on at 110-120 A, and Zr transition layer is deposited for 8-12 min.

[0018] S8 magnetron sputtering deposition of ZrNbSiB boride gradient coating: Ar gas pressure adjusted to 0.9-1 Pa, bias voltage adjusted to 205-225 V, deposition temperature 215-245 °C, Zr target current turned off, ZrNbSiB magnetron sputtering target current turned on to 65 A, deposit ZrNbSiB composite layer for 5-6 min; other parameters unchanged, ZrNbSiB magnetron sputtering target current increased to 70 A, deposit ZrNbSiB composite layer for 5-6 min; every 5-6 min, target current increased by 5 A until target current increased to 110 A, then deposit ZrNbSiB composite layer for 5-6 min again.

[0019] S9 post-processing: Turn off the power supply, ion source and gas source of each target, and the coating process is complete.

[0020] Preferably, in step S6, the carbonization process using C ion plating target material has a particle diameter of 30-60 nm, resulting in high deposition rate, good surface quality, and excellent performance.

[0021] Preferably, in step S7, the Zr transition layer is deposited using a Zr ion plating target. The Zr powder particles used in the target have a diameter of 60-90 nm, resulting in a high deposition rate, good surface quality, and excellent performance.

[0022] Preferably, in step S8, the ZrNbSiB boride gradient coating is deposited using a ZrNbSiB magnetron sputtering target. The target uses powder particles with a diameter of 60-120 nm, resulting in a high deposition rate, good surface quality, and excellent performance. The atomic percentage content of each element is: Zr 55-65 at.%, Nb 10-20 at.%, Si 5-10 at.%, and B 10-20 at.%.

[0023] Preferably, the base material of the blade corner is one of Q345, Q460, 45 steel and 40Cr medium carbon steel and their alloy steels.

[0024] On the other hand, the present invention provides an engineering machinery cutting edge prepared by the above-described preparation process.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The engineering machinery cutting edge and its preparation process of the present invention, through quenching and high-temperature tempering treatment, can ensure sufficient toughness and impact deformation resistance of the core; through surface ion carburizing treatment, carbon atoms are diffused into the interior of the workpiece, and the concentration of carbon atoms gradually decreases with increasing depth, which is conducive to the formation of a high-hardness and high-strength carbide gradient diffusion layer, thereby providing a strong supporting substrate and good bonding performance for the subsequent preparation of ZrNbSiB boride gradient coating; and through ion plating to deposit a Zr transition layer on the surface, a ZrNbSiB boride gradient coating with a compositional gradient is prepared by magnetron sputtering. Since the Zr transition layer and the ZrNbSiB boride coating have similar properties, the performance difference between the ZrNbSiB boride gradient coating and the substrate material can be mitigated, the matching performance in structure and performance can be improved, and the bonding force between the ZrNbSiB boride gradient coating and the substrate material and the impact resistance of the coating can be increased. Meanwhile, in this ZrNbSiB boride gradient coating, Zr acts as a solid solution strengthener, improving the coating's strength and wear resistance. Nb increases the coating's hardness, strength, compressive strength, wear resistance, and corrosion resistance, while Si improves the coating's hardness and resistance to chemical diffusion. The compositionally graded ZrNbSiB boride gradient coating can prevent the propagation of coating cracks and improve the physical and mechanical properties of the workpiece.

[0027] 2. The manufacturing process of the bulldozer blade corner of this invention enhances the adhesion between the coating and the substrate by 1.5-2 times, reduces friction and wear during operation, and increases surface hardness by nearly 3 times. Due to the use of physical vapor deposition technology for carburizing and coating treatment, the processing time is shortened by more than 90%, extending the service life of the bulldozer blade corner by more than 1.5 times. Furthermore, it uses the most commonly used and inexpensive medium carbon steels such as Q345, Q460, 45 steel, and 40Cr, as well as their alloy steels, instead of expensive special alloy steels such as 31Si2CrMoB, reducing the maintenance and upkeep costs of the bulldozer blade corner by more than 75%. Simultaneously, because the manufacturing process temperature can be controlled below 300℃, it will not cause changes in the substrate microstructure and surface dimensions of the blade corner parts, allowing for direct installation and use after processing. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the surface structure of the cutting edge of the engineering machinery according to the present invention.

[0029] Figure 2 This is the surface morphology and cloud map of the bulldozer blade corner coating prepared in Example 1 of the present invention.

[0030] Figure 3 This is the morphology and cloud map of the adhesion scratches of the bulldozer blade corner coating prepared in Example 1 of the present invention.

[0031] Figure 4 This is a magnified image of the surface wear marks on the bulldozer blade corner coating prepared in Example 1 of the present invention.

[0032] In the figure, 1 is the knife-corner substrate; 2 is the surface carburized diffusion layer; 3 is the Zr transition layer; and 4 is the ZrNbSiB boride gradient coating. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention.

[0034] Example 1

[0035] The manufacturing process of the cutting edge of the engineering machinery in this embodiment is as follows: After rolling, quenching, and high-temperature tempering, the cutting edge substrate 1 is subjected to surface carburizing treatment by ion plating to form a surface carburizing diffusion layer 2; then, a Zr transition layer 3 is deposited by ion plating, and a ZrNbSiB boride gradient coating 4 is deposited on the Zr transition layer 3 by magnetron sputtering. The cutting edge substrate 1 is made of Q345 steel, a 25mm thick formed steel plate; during deposition, two C ion plating targets, one Zr ion plating target, and one ZrNbSiB magnetron sputtering target are used.

[0036] Specifically, the manufacturing process of the cutting edge of the engineering machinery in this embodiment includes the following steps:

[0037] S1 Chamfering: A 25mm thick Q345 steel sheet is rolled into a 230mm×180mm blank, the surface is deburred, and the chamfer is C3.

[0038] S2 blade corner heat treatment: Quenching (840℃, oil cooling) → High temperature tempering (615℃, holding time 140min; cooling method: air cooling);

[0039] S3 Cutting Corner Surface Treatment: Immerse the cutting corner parts sequentially in alcohol and acetone, ultrasonically clean for 50 minutes each, to remove surface impurities and other adhering substances. After thorough drying, quickly place them in a PVD composite coating machine and vacuum to 6.0×10⁻⁶. -3 Pa, heat to 300℃, and hold for 40 minutes;

[0040] S4 blade corner surface glow discharge cleaning: Ar gas is introduced at a pressure of 1.7 Pa and a temperature of 260 °C. The bias power supply is turned on with a voltage of 550 V and a duty cycle of 0.2. The surface glow discharge cleaning is performed for 30 min.

[0041] S5 blade corner surface ion cleaning: bias voltage adjusted to 450V, duty cycle 0.3, Ar gas pressure 1Pa, temperature 240℃, ion source turned on, ion cleaning for 10min, two C target power supplies turned on, C target current 110A, ion bombardment for 3min.

[0042] S6 blade corner ion plating and carburizing: C ion plating target material is used, and the C powder particle diameter of the target material is 30nm; the C target ion plating power supply is adjusted to 100A, Ar gas pressure is 1.3Pa, substrate bias voltage is adjusted to 370V, temperature is 230℃, and ion carburizing is performed for 25min.

[0043] S7 ion plating deposition of Zr transition layer 3: Zr ion plating target material is used, and the Zr powder particle diameter of the target material is 60nm; Ar gas pressure is adjusted to 1Pa, bias voltage drop is 320V, deposition temperature is 220℃, C target current is turned off, Zr target ion plating current is turned on at 110A, and Zr transition layer is deposited for 38min.

[0044] S8 Magnetron Sputtering Deposition of ZrNbSiB Boride Gradient Coating 4: A ZrNbSiB magnetron sputtering target was used, with powder particles of 70 nm in diameter and atomic percentages of Zr 55 at.%, Nb 20 at.%, Si 10 at.%, and B 15 at.%. The Ar gas pressure was set to 0.9 Pa, the bias voltage to 205 V, and the deposition temperature to 215 °C. The Zr target current was turned off, and the ZrNbSiB magnetron sputtering target current was turned on to 65 A for 5 min of ZrNbSiB composite layer deposition. Other parameters remained unchanged, and the ZrNbSiB magnetron sputtering target current was increased to 70 A for 5 min of ZrNbSiB composite layer deposition. Every 5 min, the target current was increased by 5 A until it reached 110 A, and then the ZrNbSiB composite layer was deposited for another 5 min.

[0045] S9 post-processing: Turn off the power supply, ion source and gas source of each target, and the coating process is complete.

[0046] like Figure 1 As shown, the engineering machinery cutting edge obtained in this embodiment has the following structure: from the inside to the outside, the cutting edge substrate 1 has a surface carburizing diffusion layer 2, a Zr transition layer 3, and a ZrNbSiB boride gradient coating 4.

[0047] The ZrNbSiB wear-resistant coating prepared in this embodiment achieved a microhardness of HV2520-2540 (testing equipment: HVS-1000A micro Vickers hardness tester, load 0.5N), which is nearly three times higher than the surface hardness (HV635-660) of the traditional single carburizing process. The coating thickness is approximately 1.9-2 μm, and the surface roughness is only Ra 11-16 μm. The optical morphology and contour plot of the coating surface are shown below. Figure 2 As shown.

[0048] The adhesion between the coating and the blade-shaped substrate 1 is 74-85 N, which is 150-200% higher than the adhesion of a simple PVD coating (25-30 N). The optical morphology and contour plot of the scratch are shown below. Figure 3 As shown, the coating adhesion performance is significantly improved. Under the same friction test conditions (HRT-A02 ball-and-disc friction and wear tester, reciprocating linear motion, grinding balls made of bearing steel with a surface hardness of HRC55-60, load of 100N, sliding speed of 10mm / s, grinding time of 30min), the average friction coefficient of the ZrNbSiB wear-resistant coating prepared in this embodiment is only 0.40-0.45, which is 20% lower than the friction coefficient of the blade angle treated by the traditional carburizing process (0.5-0.53); the wear rate of the coating in this embodiment is only 1.86-2.07×10⁻⁶. -6 mm 3The N·m value was reduced by 70-80% compared to the knife-angle samples treated with traditional carburizing processes. The SEM morphology of the surface wear marks on the coating in this embodiment is shown below. Figure 4 As shown. The entire effective carburizing and coating process in this embodiment takes less than 2 hours, saving more than 90% of the processing time compared to traditional carburizing processes.

[0049] Example 2

[0050] The manufacturing process of the cutting edge of the engineering machinery in this embodiment is as follows: After rolling, quenching, and high-temperature tempering, the cutting edge substrate 1 is subjected to surface carburizing treatment by ion plating to form a surface carburizing diffusion layer 2; then, a Zr transition layer 3 is deposited by ion plating, and a ZrNbSiB boride gradient coating 4 is deposited on the Zr transition layer 3 by magnetron sputtering. The cutting edge substrate 1 is made of 45 steel and a 30mm thick formed steel plate; during deposition, two C ion plating targets, one Zr ion plating target, and one ZrNbSiB magnetron sputtering target are used.

[0051] Specifically, the manufacturing process of the cutting edge of the engineering machinery in this embodiment includes the following steps:

[0052] S1 Chamfer Machining: Roll a 30mm thick 45 steel plate into a 250mm×200mm blank, deburr it with a grinding wheel, and chamfer it to C2.

[0053] S2 blade corner heat treatment: Quenching (900℃, water cooling) → High temperature tempering (635℃, holding time 150min; cooling method: air cooling);

[0054] S3 Cutting Edge Surface Treatment: Immerse the cutting edge parts sequentially in alcohol and acetone, and ultrasonically clean for 60 minutes each to remove surface impurities and other adhering substances. After thorough drying, quickly place them in a PVD composite coating machine and vacuum to 6.5 × 10⁻⁶. -3 Pa, heat to 320℃, and hold for 50 minutes;

[0055] S4 blade corner surface glow discharge cleaning: Ar gas is introduced at a pressure of 2 Pa and a temperature of 285℃. The bias power supply is turned on with a voltage of 650V and a duty cycle of 0.4. The surface glow discharge cleaning is performed for 40 minutes.

[0056] S5 blade corner surface ion cleaning: bias voltage adjusted to 500V, duty cycle 0.4, Ar gas pressure 1.3Pa, temperature 260℃, ion source turned on, ion cleaning for 20min, two C target power supplies turned on, C target current 120A, ion bombardment for 5min.

[0057] S6 blade corner ion plating and carburizing: C ion plating target material is used, and the C powder particle diameter of the target material is 60nm; the C target ion plating power supply is adjusted to 105A, Ar gas pressure is 1.7Pa, substrate bias voltage is adjusted to 400V, temperature is 260℃, and ion carburizing is performed for 35min.

[0058] S7 ion plating deposition of Zr transition layer 3: Zr ion plating target material is used, and the Zr powder particle diameter of the target material is 80nm; Ar gas pressure is adjusted to 1.1Pa, bias voltage drop is 350V, deposition temperature is 250℃, C target current is turned off, Zr target ion plating current is turned on at 120A, and Zr transition layer is deposited for 312min.

[0059] S8 Magnetron Sputtering Deposition of ZrNbSiB Boride Gradient Coating 4: A ZrNbSiB magnetron sputtering target was used, with powder particles of 100 nm in diameter and atomic percentages of Zr 65 at.%, Nb 10 at.%, Si 5 at.%, and B 20 at.%. The Ar gas pressure was set to 1 Pa, the bias voltage to 225 V, and the deposition temperature to 245 °C. The Zr target current was turned off, and the ZrNbSiB magnetron sputtering target current was turned on at 65 A for 6 min to deposit the ZrNbSiB composite layer. Other parameters remained unchanged, and the ZrNbSiB magnetron sputtering target current was increased to 70 A for 6 min to deposit the ZrNbSiB composite layer. Every 6 min, the target current was increased by 5 A until it reached 110 A, and then the ZrNbSiB composite layer was deposited for another 6 min.

[0060] S9 post-processing: Turn off the power supply, ion source and gas source of each target, and the coating process is complete.

[0061] The ZrNbSiB wear-resistant coating prepared in this embodiment has a surface microhardness of HV2700, an adhesion strength of 88N, a coating thickness of 2.5μm, a surface roughness of Ra 13μm, and a total effective carburizing and coating time of approximately 1.7h.

Claims

1. A manufacturing process for cutting edges of engineering machinery, characterized in that, A surface carburizing diffusion layer (2), a Zr transition layer (3), and a ZrNbSiB boride gradient coating (4) are sequentially disposed from the inside to the outside on the surface of the knife-corner substrate (1). specific Includes the following steps: S1 cutting edge machining: rolling; S2 blade corner heat treatment: Quenching → High temperature tempering; S3 blade corner surface treatment: Immerse the blade corner in alcohol and acetone sequentially, and ultrasonically clean for 50-60 minutes each to remove surface impurities and other adhering substances. After thorough drying, quickly place it in a PVD composite coating machine and vacuum it to (6.0-6.5)×10. -3 Pa, heat to 300-320℃, and hold for 40-50 minutes; S4 blade corner surface glow discharge cleaning: Ar gas is introduced at a pressure of 1.7-2 Pa and a temperature of 260-285℃. The bias power supply voltage is 550-650V with a duty cycle of 0.2-0.

4. The surface glow discharge cleaning is performed for 30-40 minutes. S5 blade corner surface ion cleaning: adjust the bias voltage to 450-500V, duty cycle 0.3-0.4, Ar gas pressure 1-1.3Pa, temperature 240-260℃, turn on the ion source, ion cleaning for 10-20min, turn on the two C target power supplies, C target current 110-120A, ion bombardment for 3-5min. S6 blade corner ion plating and carburizing: C target ion plating power supply is adjusted to 100-105A, Ar gas pressure is 1.3-1.7Pa, substrate bias voltage is adjusted to 370-400V, temperature is 230-260℃, and ion carburizing is performed for 25-35min. S7 ion plating deposition of Zr transition layer (3): Ar gas pressure is adjusted to 1-1.1 Pa, bias voltage drop is 320-350 V, deposition temperature is 220-250 ℃, C target current is turned off, Zr target ion plating current is turned on at 110-120 A, and Zr transition layer (3) is deposited for 8-12 min. S8 magnetron sputtering deposition of ZrNbSiB boride gradient coating (4): Ar gas pressure is adjusted to 0.9-1 Pa, bias voltage is adjusted to 205-225 V, deposition temperature is 215-245 °C, Zr target current is turned off, ZrNbSiB magnetron sputtering target current is turned on to 65 A, and ZrNbSiB composite layer is deposited for 5-6 min; other parameters remain unchanged, ZrNbSiB magnetron sputtering target current is increased to 70 A, and ZrNbSiB composite layer is deposited for 5-6 min; every 5-6 min, the target current is increased by 5 A until the target current is increased to 110 A, and then ZrNbSiB composite layer is deposited for 5-6 min; S9 post-processing: Turn off the power supply, ion source and gas source of each target, and the coating process is complete.

2. The manufacturing process of the cutting edge of engineering machinery as described in claim 1, characterized in that, In step S6, the carbonization process using C ion plating targets has a particle diameter of 30-60 nm.

3. The manufacturing process of the cutting edge of engineering machinery as described in claim 1, characterized in that, In step S7, the Zr transition layer (3) is deposited using a Zr ion plating target with a Zr powder particle diameter of 60-90 nm.

4. The manufacturing process of the cutting edge for engineering machinery as described in claim 1, characterized in that, In step S8, the ZrNbSiB boride gradient coating (4) is deposited using a ZrNbSiB magnetron sputtering target. The powder particles used in the target have a diameter of 60-120 nm and the atomic percentage content of each element is: Zr 55-65 at.%, Nb 10-20 at.%, Si 5-10 at.%, B 10-20 at.%.

5. The manufacturing process of the cutting edge of engineering machinery as described in claim 1, characterized in that, The material of the blade corner base (1) is one of Q345, Q460, 45 steel and 40Cr medium carbon steel and their alloy steel.

6. The cutting edge of an engineering machinery prepared by the preparation process according to any one of claims 1-5.

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