Track-type engineering machine drive wheel tooth block and method of manufacturing the same

Abstract

The present application belongs to the technical field of manufacturing engineering machinery parts, and particularly relates to a caterpillar-type engineering machinery driving wheel tooth block and a preparation method thereof. The caterpillar-type engineering machinery driving wheel tooth block is prepared by surface carburizing and coating treatment through physical vapor deposition technology, boride coating, PVD method and carburizing technology, and a carburizing diffusion layer is prepared between the carbide coating and the workpiece base through ion sputtering, that is, the surface of the workpiece is first subjected to surface carburizing treatment through ion sputtering, then a Mo transition layer is deposited on the surface by ion plating, and a MoZrWB boride coating with gradient change in composition is prepared by a magnetron sputtering method, so as to slow down the difference in physical properties between the coating and the base material, improve the hardness of the base material, enhance the adhesion of the coating and the base, thereby improving the comprehensive performance of the driving wheel tooth block part, effectively improving the surface treatment efficiency and the service life of the workpiece.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery parts manufacturing technology, specifically relating to a tracked engineering machinery drive wheel tooth block and its preparation method. Background Technology

[0002] Tracked bulldozers are tracked construction machines capable of excavating, transporting, and dumping soil and rock. They have wide applications in open-pit mines, primarily for constructing spoil heaps, leveling truck spoil heaps, stockpiling dispersed ore, leveling work platforms, and building sites. Bulldozers can also be used in mining operations: stripping and mining placer deposits, traction and propulsion of scrapers and rock plows, and, in non-transportation mining methods, in conjunction with other earthmoving machinery to reduce the height of stripping steps. The final drive is the last stage of power transmission in a tracked bulldozer. Its function is to reduce the power transmitted from the engine, torque converter, and gearbox before transmitting it to the sprocket, which drives the tracks to move the machine. Therefore, the drive sprocket is the most stress-bearing part of the entire tracked construction machine's transmission system.

[0003] The drive wheel toothed block is the part of the tracked construction machinery that bears the heaviest load during operation. Currently, the drive wheel toothed blocks of traditional tracked construction machinery final drives cannot meet the harsh working conditions required by these machines. These drive wheel toothed blocks are wear parts that require frequent replacement, and the special alloy steel materials such as 40Mn2H and 35MnB used are expensive, yet their service life still falls short of expectations. This also reduces the overall working efficiency of the tracked construction machinery and increases daily maintenance and upkeep costs. Therefore, developing new drive wheel toothed blocks for tracked construction machinery and their manufacturing methods has significant practical and application value.

[0004] 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 drive wheel tooth blocks can be improved by preparing boride coatings on the surface of drive wheel tooth blocks or by carbonizing the metal surface.

[0005] 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 working 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 technology holds great potential in surface treatment. However, directly applying PVD boride coatings to the surface of tracked engineering machinery parts can lead to premature PVD coating failure due to significant differences in hardness, elastic modulus, and coefficient of thermal expansion between the substrate and the coating material. Chinese invention patent CN103727180 A directly prepared wear-resistant ceramic coating and diamond coating on the surface of carbon steel. Due to the relatively soft hardness of the substrate, which cannot support the coating, and the obvious performance difference between the substrate and the coating, the performance of the prepared coating cannot meet many practical application requirements. Especially under high-speed, heavy-load, and alternating load conditions, the coating will quickly peel off and wear. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a tracked engineering machinery drive wheel tooth block and its preparation method. The tracked engineering machinery drive wheel tooth block is surface carburized and coated using physical vapor deposition (PVD) technology. This combines boride coating, PVD, and carburizing techniques. A carburizing diffusion layer is prepared between the carbide coating and the workpiece substrate using ion sputtering. Specifically, the workpiece surface is first carburized by ion sputtering, and then a Mo transition layer is deposited on the surface using ion plating. A MoZrWB boride coating with a compositional gradient is prepared by magnetron sputtering to mitigate the difference in physical properties between the coating and the substrate material, increase the hardness of the substrate material, and enhance the adhesion between the coating and the substrate. This improves the overall performance of the drive wheel tooth block parts, effectively increasing surface treatment efficiency and the service life of the workpiece.

[0007] This invention is achieved through the following technical solution:

[0008] The material of the drive wheel tooth block of the tracked engineering machinery described in this invention is forged, quenched, and tempered at high temperature. Then, it is surface carburized by ion plating. Then, a Mo transition layer is deposited by ion plating and a MoZrWB boride coating is prepared by magnetron sputtering. During the deposition, one C ion plating target, one Mo ion plating target, and two MoZrWB magnetron sputtering composite targets are used.

[0009] The method for preparing the drive wheel tooth block of the tracked engineering machinery according to the present invention includes the following steps:

[0010] (1) Machining of drive wheel tooth block parts: forging;

[0011] (2) Heat treatment of drive wheel tooth block parts: quenching and high-temperature tempering;

[0012] (3) Surface treatment of drive wheel tooth block parts: Place the drive wheel tooth block parts in alcohol and acetone in sequence, and perform ultrasonic cleaning for 35-45 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 7.5-8.5×10 -3 Pa, heat to 260-290℃, and hold for 30-35 minutes;

[0013] (4) Surface glow discharge cleaning: Ar gas is introduced at a pressure of 2.0-2.4 Pa and a temperature of 245-275℃. The bias power supply voltage is 430-550 V with a duty cycle of 0.25-0.35. The surface glow discharge cleaning is carried out for 25-35 min.

[0014] (5) Surface ion cleaning: adjust the bias voltage to 400-450V, duty cycle 0.3-0.4, Ar gas pressure 1.3-1.5Pa, temperature 225-250℃, turn on the ion source, perform ion cleaning for 5-10min, turn on the C target power supply for ion plating, C target current 120-130A, ion bombardment for 4-5min;

[0015] (6) Ion plating and carburizing: The C target ion plating power supply is adjusted to 110-115A, the Ar gas pressure is 1.3-1.5Pa, the substrate bias voltage is adjusted to 350-450V, the temperature is 225-250℃, and ion carburizing is carried out for 30-35min.

[0016] (7) Ion plating to deposit Mo transition layer: Ar gas pressure is adjusted to 1.3-1.5 Pa, bias voltage drop is 240-275 V, deposition temperature is 220-245 °C, C target current is turned off, Mo target ion plating current is turned on at 110-115 A, and Mo transition layer is deposited for 7-10 min.

[0017] (8) Magnetron sputtering deposition of MoZrWB boride gradient coating: Ar gas pressure is adjusted to 0.7-0.9 Pa, bias voltage is adjusted to 200-220 V, deposition temperature is 220-250 °C, Mo target current is turned off, MoZrWB magnetron sputtering target current is turned on to 60 A, and MoZrWB composite layer is deposited for 3-4 min; other parameters remain unchanged, increase MoZrWB magnetron sputtering target current to 65 A, and deposit MoZrWB composite layer for 3-4 min; every 3-4 min, target current is increased by 5 A until target current is increased to 120 A, and then MoZrWB composite layer is deposited for 3-4 min;

[0018] (9) Post-processing: Turn off the power supply, ion source and gas source of each target, and the coating is finished.

[0019] Preferably, the base material of the drive wheel tooth block part includes one of medium carbon steel 45 steel, 40Cr steel and their alloy steel.

[0020] Preferably, the drive wheel tooth block part obtained by the method of the present invention has the following structure: a surface carburizing diffusion layer, a Mo transition layer, and a MoZrWB boride gradient coating are sequentially formed on the surface of the substrate.

[0021] Preferably, in step (6), the ion plating carburizing uses a C ion plating target material, and the C powder particles used in the target material have a diameter of 50-70 nm.

[0022] Preferably, in step (7), the Mo transition layer is deposited by ion plating using a Mo ion plating target with a particle diameter of 50-90 nm.

[0023] Preferably, in step (8), the MoZrWB boride gradient coating is deposited by magnetron sputtering using a MoZrWB 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 in the target is: Mo: 50-60 at.%, Zr: 15-20 at.%, W: 10-15 at.%, B: 15-20 at.%.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The tracked engineering machinery drive wheel tooth block 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 matrix and good bonding performance for the subsequent preparation of MoZrWB boride coating; and through ion plating to deposit a Mo transition layer on the surface, a MoZrWB boride coating with a compositional gradient is prepared by magnetron sputtering. The Mo transition layer has similar performance to the MoZrWB coating, which can mitigate the performance difference between the coating and the substrate material, improve the matching performance of structure and performance, increase the bonding force between the MoZrWB coating and the substrate, and improve the impact resistance of the coating. Meanwhile, in this MoZrWB boride gradient coating, Mo increases the coating's hardness and strength while reducing its coefficient of friction; Zr strengthens the coating through solid solution, enhancing its strength and wear resistance; and W improves its hardness, resistance to chemical diffusion, and oxidation resistance. This compositionally graded MoZrWB boride coating can prevent crack propagation and improve the physical and mechanical properties of the workpiece.

[0026] 2. The preparation method of the tracked engineering machinery drive wheel tooth block described in this invention can enhance the adhesion performance between the coating and the substrate by more than 1.5 times, reduce the friction and wear of parts during operation, and increase the surface hardness by nearly 4 times. Due to the use of physical vapor deposition technology for carburizing and coating treatment, the carburizing process is shortened by more than 90%, extending the service life of the tracked engineering machinery drive wheel tooth block by more than 1.5 times. Furthermore, the most common medium carbon steels such as 45 steel and 40Cr, and their alloy steels, are used instead of expensive special alloy steels such as 40Mn2H and 35MnB, reducing the maintenance and upkeep costs of the tracked engineering machinery drive wheel tooth block by 65%-70%. Simultaneously, because the preparation process temperature can be controlled below 300℃, it will not cause changes in the microstructure and surface dimensions of the drive wheel tooth block parts, allowing for direct installation and use after processing. Attached Figure Description

[0027] Figure 1 A schematic diagram of the surface structure of the drive wheel tooth block part of the tracked engineering machinery according to the present invention. In the figure: 1. Part substrate, 2. Carburized diffusion layer on the surface of the substrate, 3. Mo transition layer, 4. MoZrWB boride coating.

[0028] Figure 2 The optical morphology of the coating surface of the tracked engineering machinery drive wheel tooth block part prepared in Example 1 of the present invention;

[0029] Figure 3The optical morphology of the coating adhesion force scratches on the tooth block parts of the tracked engineering machinery drive wheel prepared in Example 1 of this invention;

[0030] Figure 4 The average friction coefficient curve of the novel tracked engineering machinery drive wheel tooth block and the traditional tooth block prepared in Example 1 of this invention;

[0031] Figure 5 The surface wear marks and magnified image of the coating on the tooth block part of the tracked engineering machinery drive wheel prepared in Example 1 of this invention. Detailed Implementation

[0032] The following provides two preferred embodiments of the present invention, and the invention will be further described in conjunction with the embodiments. Unless otherwise specified, all raw materials used in the embodiments are commercially available.

[0033] Example 1

[0034] The drive wheel tooth block of the tracked engineering machinery described in this invention is a drive wheel tooth block for a 240-horsepower tracked engineering machinery, made of forged steel of 45 steel. After forging, quenching, and high-temperature tempering, the drive wheel tooth block material undergoes surface carburizing treatment using ion plating. Then, a Mo transition layer is deposited by ion plating, followed by the preparation of a MoZrWB boride coating using magnetron sputtering. During deposition, one C ion plating target, one Mo ion plating target, and two MoZrWB magnetron sputtering composite targets are used (the atomic percentage content of each element in the target material is: Mo: 50 at.%, Zr: 20 at.%, W: 15 at.%, B: 15 at.%). The specific preparation method includes the following steps:

[0035] (1) Machining of drive wheel tooth block parts: tooth block forging, forging fillet radius R3-R4;

[0036] (2) Heat treatment of drive wheel tooth block parts: quenching (870℃, oil cooling) → high temperature tempering (600℃, holding time: 130min; cooling method: air cooling).

[0037] (3) Surface treatment of drive wheel tooth block parts: The drive wheel tooth block parts are placed in alcohol and acetone in sequence, and ultrasonically cleaned for 35 minutes each to remove surface impurities and other attachments. After being fully dried, they are quickly placed in a PVD composite coating machine and vacuumed to 7.5×10 -3 Pa, heat to 260℃, and hold for 30 minutes;

[0038] (4) Surface glow discharge cleaning: Ar gas is introduced at a pressure of 2.0 Pa and a temperature of 245 °C. The bias power supply is turned on with a voltage of 430 V and a duty cycle of 0.25. The surface glow discharge cleaning is performed for 25 min.

[0039] (5) Surface ion cleaning: the bias voltage is adjusted to 400V, the duty cycle is 0.3, the Ar gas pressure is 1.3Pa, the temperature is 225℃, the ion source is turned on, the ion cleaning is performed for 5min, the C target power supply for ion plating is turned on, the C target current is 120A, and the ion bombardment is performed for 4min.

[0040] (6) Ion plating and carburizing: The C target ion plating power supply is set to 110A, the Ar gas pressure is 1.3Pa, the substrate bias voltage is set to 350V, the temperature is 225℃, and ion carburizing is carried out for 30min.

[0041] (7) Ion plating to deposit Mo transition layer: Ar gas pressure is adjusted to 1.3 Pa, bias voltage drop is 240 V, deposition temperature is 220 °C, C target current is turned off, Mo target ion plating current is turned on at 110 A, and Mo transition layer is deposited for 7 min.

[0042] (8) Magnetron sputtering deposition of MoZrWB boride gradient coating: Ar gas pressure is adjusted to 0.7 Pa, bias voltage is adjusted to 200 V, deposition temperature is 220 °C, Mo target current is turned off, MoZrWB magnetron sputtering target current is turned on to 60 A, and MoZrWB composite layer is deposited for 3 min; other parameters remain unchanged, increase MoZrWB magnetron sputtering target current to 65 A, and deposit MoZrWB composite layer for 3 min; every 3 min, target current is increased by 5 A until target current is increased to 120 A, and then MoZrWB composite layer is deposited for 3 min;

[0043] (9) Post-processing: Turn off the power supply, ion source and gas source of each target, and the coating is finished.

[0044] The MoZrWB wear-resistant coating prepared in this embodiment achieved a microhardness of HV2440 (testing equipment: HVS-1000A micro Vickers hardness tester, applied load 0.5N), which is nearly four times the surface hardness (HV630-640) of a single traditional carburizing process. The average coating thickness is approximately 1.78 μm, and the surface morphology of the coating is as follows. Figure 2 As shown, the average bonding force between the coating and the drive wheel tooth block substrate is 72N, which is 2.5-3 times that of the bonding force of a simple PVD coating (28-33N). The coating bonding scratch morphology is as follows. Figure 3 As shown, coating residue remains at the end of the scratch test, indicating a significant improvement in coating adhesion. 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, and grinding time of 30min), the average friction coefficient of the MoZrWB wear-resistant coating prepared in this invention is only 0.44, which is 20% lower than the friction coefficient of the drive wheel teeth block treated by the traditional carburizing process (0.54-0.58). The average friction coefficient comparison curve is shown in Figure 1. Figure 4As shown; the average wear rate of this coating is only 1.99 × 10⁻⁶. -6 mm 3 / N·m, which is 70-80% lower than that of drive wheel tooth block samples treated with traditional carburizing process. The surface wear morphology of this coating is as follows. Figure 5 As shown, the coating exhibits good performance, with residue remaining even after prolonged friction. The entire effective carburizing and coating process takes less than 2 hours, saving over 90% of the processing time compared to traditional carburizing processes.

[0045] Example 2

[0046] The tracked engineering machinery drive wheel tooth block of this invention is a drive wheel tooth block for a 520-horsepower tracked bulldozer, made of forged steel of 40Cr steel. After forging, quenching, and high-temperature tempering, the drive wheel tooth block material undergoes surface carburizing treatment using ion plating. Then, a Mo transition layer is deposited by ion plating, followed by the preparation of a MoZrWB boride coating using magnetron sputtering. During deposition, one C ion plating target, one Mo ion plating target, and two MoZrWB magnetron sputtering composite targets are used (the atomic percentage content of each element in the target material is: Mo: 60 at.%, Zr: 15 at.%, W: 10 at.%, B: 15 at.%). The specific preparation method includes the following steps:

[0047] (1) Machining of drive wheel tooth block parts: forging, forging fillet R4-R5;

[0048] (2) Heat treatment of drive wheel tooth block parts: quenching (880℃, water cooling) → high temperature tempering (590℃, holding time: 160min; cooling method: air cooling);

[0049] (3) Surface treatment of drive wheel tooth block parts: The drive wheel tooth block parts are placed in alcohol and acetone in sequence, and ultrasonically cleaned for 45 minutes each to remove surface impurities and other attachments. After being fully dried, they are quickly placed in a PVD composite coating machine and vacuumed to 8.5×10 -3 Pa, heat to 290℃, and hold for 35 minutes;

[0050] (4) Surface glow discharge cleaning: Ar gas is introduced at a pressure of 2.4 Pa and a temperature of 275 °C. The bias power supply is turned on with a voltage of 550 V and a duty cycle of 0.35. The surface glow discharge cleaning is performed for 35 min.

[0051] (5) Surface ion cleaning: the bias voltage is adjusted to 450V, the duty cycle is 0.40, the Ar gas pressure is 1.5Pa, the temperature is 250℃, the ion source is turned on, the ion cleaning is performed for 10min, the C target power supply for ion plating is turned on, the C target current is 130A, and the ion bombardment is performed for 5min.

[0052] (6) Ion plating and carburizing: The C target ion plating power supply is set to 115A, the Ar gas pressure is 1.5Pa, the substrate bias voltage is set to 450V, the temperature is 250℃, and ion carburizing is carried out for 35min.

[0053] (7) Ion plating to deposit Mo transition layer: Ar gas pressure is adjusted to 1.5 Pa, bias voltage drop is 275 V, deposition temperature is 245 °C, C target current is turned off, Mo target ion plating current is turned on at 115 A, and Mo transition layer is deposited for 10 min.

[0054] (8) Magnetron sputtering deposition of MoZrWB boride gradient coating: Ar gas pressure is adjusted to 0.9 Pa, bias voltage is adjusted to 220 V, deposition temperature is 250 °C, Mo target current is turned off, MoZrWB magnetron sputtering target current is turned on to 60 A, and MoZrWB composite layer is deposited for 4 min; other parameters remain unchanged, increase MoZrWB magnetron sputtering target current to 65 A, and deposit MoZrWB composite layer for 4 min; every 4 min, target current is increased by 5 A until target current is increased to 120 A, and then MoZrWB composite layer is deposited for 4 min;

[0055] (9) Post-processing: Turn off the power supply, ion source and gas source of each target, and the coating is finished.

[0056] The prepared MoZrWB wear-resistant coating has a surface microhardness of HV2540, an average adhesion strength of 87N, an average coating thickness of 2.18μm, and the entire effective carburizing and coating time is less than 2 hours.

[0057] Example 3

[0058] The tracked engineering machinery drive wheel tooth block of this invention is a drive wheel tooth block for a 520-horsepower tracked bulldozer, made of forged steel of 40Cr steel. After forging, quenching, and high-temperature tempering, the drive wheel tooth block material undergoes surface carburizing treatment using ion plating. Then, a Mo transition layer is deposited by ion plating, followed by the preparation of a MoZrWB boride coating using magnetron sputtering. During deposition, one C ion plating target, one Mo ion plating target, and two MoZrWB magnetron sputtering composite targets are used (the atomic percentage content of each element in the target material is: Mo: 55 at.%, Zr: 18 at.%, W: 12 at.%, B: 15 at.%). The specific preparation method includes the following steps:

[0059] (1) Machining of drive wheel tooth block parts: forging, forging fillet R4-R5;

[0060] (2) Heat treatment of drive wheel tooth block parts: quenching (880℃, water cooling) → high temperature tempering (590℃, holding time: 160min; cooling method: air cooling);

[0061] (3) Surface treatment of drive wheel tooth block parts: The drive wheel tooth block parts are placed in alcohol and acetone in sequence, and ultrasonically cleaned for 40 minutes each to remove surface impurities and other attachments. After being fully dried, they are quickly placed in a PVD composite coating machine and vacuumed to 8×10 -3 Pa, heat to 280℃, and hold for 32 minutes;

[0062] (4) Surface glow discharge cleaning: Ar gas is introduced at a pressure of 2.2 Pa and a temperature of 260 °C. The bias power supply is turned on with a voltage of 500 V and a duty cycle of 0.3. The surface glow discharge cleaning is performed for 30 min.

[0063] (5) Surface ion cleaning: the bias voltage is adjusted to 420V, the duty cycle is 0.35, the Ar gas pressure is 1.4Pa, the temperature is 235℃, the ion source is turned on, the ion cleaning is performed for 8min, the C target power supply for ion plating is turned on, the C target current is 123A, and the ion bombardment is performed for 4min.

[0064] (6) Ion plating and carburizing: The C target ion plating power supply is set to 112A, the Ar gas pressure is 1.4Pa, the substrate bias voltage is set to 400V, the temperature is 235℃, and ion carburizing is carried out for 32min.

[0065] (7) Ion plating to deposit Mo transition layer: Ar gas pressure is adjusted to 1.4 Pa, bias voltage drop is 260 V, deposition temperature is 230 °C, C target current is turned off, Mo target ion plating current is turned on at 112 A, and Mo transition layer is deposited for 9 min.

[0066] (8) Magnetron sputtering deposition of MoZrWB boride gradient coating: Ar gas pressure is adjusted to 0.8 Pa, bias voltage is adjusted to 210 V, deposition temperature is 235 °C, Mo target current is turned off, MoZrWB magnetron sputtering target current is turned on to 60 A, and MoZrWB composite layer is deposited for 3 min; other parameters remain unchanged, increase MoZrWB magnetron sputtering target current to 65 A, and deposit MoZrWB composite layer for 3 min; every 3 min, target current is increased by 5 A until target current is increased to 120 A, and then MoZrWB composite layer is deposited for 3 min;

[0067] (9) Post-processing: Turn off the power supply, ion source and gas source of each target, and the coating is finished.

[0068] The prepared MoZrWB wear-resistant coating has a surface microhardness of HV2540, an average adhesion strength of 85N, an average coating thickness of 2.04μm, and the entire effective carburizing and coating time is less than 2 hours.

Claims

1. A method for preparing a drive wheel tooth block for tracked engineering machinery, characterized in that: Includes the following steps: (1) Machining of drive wheel tooth block parts: forging; (2) Heat treatment of drive wheel tooth block parts: quenching and high-temperature tempering; (3) Surface treatment of drive wheel tooth block parts: The drive wheel tooth block parts are placed in alcohol and acetone in sequence for ultrasonic cleaning, dried, and then quickly placed in a PVD composite coating machine and vacuumed to (7.5-8.5)×10 -3 Pa, heat to 260-290℃, and hold for 30-35 minutes; (4) Surface glow discharge cleaning: Ar gas is introduced at a pressure of 2.0-2.4 Pa and a temperature of 245-275℃. The bias power supply voltage is 430-550V and the duty cycle is 0.25-0.

35. Surface glow discharge cleaning is performed. (5) Surface ion cleaning: adjust the bias voltage to 400-450V, duty cycle 0.3-0.4, Ar gas pressure 1.3-1.5Pa, temperature 225-250℃, turn on the ion source, perform ion cleaning, turn on the C target power supply for ion plating, C target current 120-130A, ion bombardment 4-5min; (6) Ion plating and carburizing: The C target power supply for ion plating is set to 110-115A, the Ar gas pressure is 1.3-1.5Pa, the substrate bias voltage is set to 350-450V, the temperature is 225-250℃, and ion carburizing is carried out for 30-35min. (7) Ion plating to deposit Mo transition layer: Ar gas pressure is adjusted to 1.3-1.5 Pa, bias voltage drop is 240-275 V, deposition temperature is 220-245 °C, C target current is turned off, ion plating Mo target current is turned on at 110-115 A, and Mo transition layer is deposited for 7-10 min. (8) Magnetron sputtering deposition of MoZrWB boride gradient coating: Ar gas pressure is adjusted to 0.7-0.9 Pa, bias voltage is adjusted to 200-220 V, deposition temperature is 220-250 °C, Mo target current is turned off, MoZrWB magnetron sputtering target current is turned on to 60 A, and MoZrWB composite layer is deposited for 3-4 min; other parameters remain unchanged, increase MoZrWB magnetron sputtering target current to 65 A, and deposit MoZrWB composite layer for 3-4 min; every 3-4 min, target current is increased by 5 A until target current is increased to 120 A, and then MoZrWB composite layer is deposited for 3-4 min; (9) Post-processing: Turn off the power supply, ion source and gas source of each target, and the coating process is complete; The drive wheel tooth block part prepared by the method has the following structure: a surface carburizing diffusion layer, a Mo transition layer, and a MoZrWB boride gradient coating are sequentially formed on the surface of the substrate. In step (6), the ion plating carburizing uses an ion plating C target material, and the C powder particles used in the target material have a diameter of 50-70 nm. In step (7), the ion plating deposited Mo transition layer uses an ion plating Mo target, and the Mo powder particles used in the target have a diameter of 50-90 nm. In step (8), the MoZrWB boride gradient coating is deposited by magnetron sputtering using a MoZrWB 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 in the target is: Mo: 50-60 at.%, Zr: 15-20 at.%, W: 10-15 at.%, B: 15-20 at.%.

2. The method for preparing the drive wheel tooth block of tracked engineering machinery as described in claim 1, characterized in that: The base material of the drive wheel tooth block part includes either 45 steel or 40Cr steel.

3. The tracked engineering machinery drive wheel tooth block prepared by the preparation method described in claim 1, characterized in that: The material of the drive wheel tooth block is forged, quenched, and tempered at high temperature. Then, it is surface carburized by ion plating. Then, a Mo transition layer is deposited by ion plating and a MoZrWB boride coating is prepared by magnetron sputtering. During deposition, one ion plating C target, one ion plating Mo target, and two MoZrWB magnetron sputtering targets are used.

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