Laser cladding device for small-diameter deep hole inner wall crack-free high-hardness alloy

Abstract

The invention discloses a small-diameter deep hole inner wall crack-free high-hardness alloy laser cladding device, and relates to the technical field of laser cladding machining. Comprising a base which is provided with a sliding rail; the main shaft machine tool is arranged on the base, the main shaft machine tool is in driving connection with a chuck, and the chuck is used for clamping a workpiece; the three-axis transmission table is in sliding connection with the sliding rail, a vertical guide rail is arranged on the three-axis transmission table, and a horizontal guide rail is arranged on a sliding block of the vertical guide rail; and the cladding gun is arranged on the sliding block of the horizontal guide rail. Through cooperation of the three-axis transmission table and the spindle machine tool, accurate four-axis movement of the cladding gun relative to the inner wall of the deep hole is achieved, the device can adapt to cladding of the inner walls of holes with different diameters and depths, stable and continuous scanning can be achieved on the inner wall of the whole deep hole, and a foundation is laid for high-quality cladding.

Description

Technical Field

[0001] This invention relates to the field of laser cladding technology, and in particular to a laser cladding device for a high-hardness alloy with no cracks in the inner wall of a small-diameter deep hole. Background Technology

[0002] In engineering plastics extrusion, injection molding, and modified granulation, key mold components such as feed tubes and figure-eight sleeves contain small-diameter, deep-pore structures. Their inner walls are subjected to long-term high-temperature, high-pressure erosion and corrosion from the molten plastic, as well as abrasive wear from reinforcing fillers such as glass fibers. Failure modes primarily manifest as inner wall scratches and wear corrosion, leading to scratches and reduced product quality. Reinforcing the inner walls with high-hardness, wear-resistant alloys (such as nickel-based tungsten carbide composites) is one of the most effective solutions for extending mold life.

[0003] However, existing technologies face a series of inherent challenges when performing laser cladding on the inner walls of such slender deep holes, leading to a tendency for the high-hardness alloy cladding layer to crack and insufficient process stability. These challenges are specifically manifested in the following aspects: 1. Conventional lateral powder feeding cladding: This method uses a standard external wall cladding head, which is tilted or extended laterally. This method can be applied when the hole diameter is large, but for small-diameter deep holes, the size of the cladding head is limited, and the powder flow from the side is prone to collision and rebound with the hole wall, resulting in extremely low powder utilization, poor coating uniformity, and inability to achieve coaxial protection, making the molten pool prone to oxidation.

[0004] 2. Simple Internal Aperture Cladding Head: This type uses a slender rod structure to guide the beam and powder into the aperture. However, the excessively reduced optical and powder feeding channels to accommodate the small aperture often lead to decreased beam quality, focused spot distortion, and poor powder convergence. Simultaneously, heat dissipation is difficult in the confined space, the lens is susceptible to heat contamination and splash damage, requiring frequent maintenance and hindering long-term stable operation. Summary of the Invention

[0005] The main objective of this invention is to provide a laser cladding device for high-hardness alloys with no cracks in the inner wall of small-diameter deep holes, so as to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides a laser cladding device for high-hardness alloys with crack-free inner walls in small-diameter deep holes, comprising: A base, on which a slide rail is provided; A spindle machine tool is mounted on the base, and a chuck is driven and connected to the spindle machine tool for clamping workpieces; A three-axis transmission table is slidably connected to the slide rail. A vertical guide rail is provided on the three-axis transmission table, and a horizontal guide rail is provided on the slider of the vertical guide rail. A cladding gun, which is mounted on the slider of the horizontal guide rail.

[0007] Furthermore, the cladding gun includes: a gun head assembly, a gun body assembly, and a gun tail assembly; The gun tail assembly includes: An optical lens mount is mounted on the slider of the horizontal guide rail to ensure long-term stability of the optical path and to perform precise calibration of the optical path. A focusing structure is disposed on the optical lens mount and is used to adjust the size of the laser spot; A protection module is disposed at the end of the focusing structure away from the optical mount, and a protective lens is disposed within the protection module; The gun body assembly includes: a metal tube, which is disposed on the protective module and communicates with the optical lens mount, and a plurality of focusing lenses are disposed inside the metal tube; The gun head assembly includes: The gun head body is located at the end of the metal tube away from the gun tail assembly. The gun head body is provided with a conical light-emitting nozzle, a copper mirror, and a powder feeding pipe. The conical light-emitting nozzle is connected to a gas supply system for spraying gas. The powder feeding pipe is connected to a powder feeding system for spraying alloy powder.

[0008] Furthermore, the slider of the horizontal guide rail is also provided with a support rod parallel to the cladding gun, and the other end of the support rod is provided with an integrated heating device, which is used to heat the workpiece.

[0009] Furthermore, the integrated heating device includes: an induction heating coil, an insulation layer provided on the outside of the induction heating coil, and an induction heating coil electrically connected to a heating power source.

[0010] Furthermore, the integrated heating device also includes an infrared thermometer, which is used to detect the temperature of the workpiece.

[0011] Furthermore, a control panel is provided on the base, and the control panel is electrically connected to the slide rail, the spindle machine tool, the three-axis transmission table, the cladding gun and the integrated heating device.

[0012] Furthermore, a roller assembly and a center frame are slidably connected on the slide rail.

[0013] The present invention has the following beneficial effects

[0014] 1. Compact structure and strong adaptability: Through the cooperation of the three-axis transmission table and the spindle machine tool, the cladding gun achieves precise four-axis (X,Y,Z,C) movement relative to the inner wall of the deep hole, which can adapt to the cladding of the inner wall of the hole with different diameters and depths, and can achieve stable and continuous scanning of the entire inner wall of the deep hole, laying the foundation for high-quality cladding.

[0015] 2. Effectively suppresses cracks: The integrated heating device enables online preheating and interlayer heat preservation of the workpiece, which significantly reduces the temperature gradient and cooling rate during the cladding process, greatly alleviates thermal stress, and fundamentally suppresses the generation of cracks in the high-hardness alloy cladding layer.

[0016] 3. High and stable cladding quality: The coaxial powder feeding ensures that the powder flows straight and does not disperse, resulting in extremely high utilization rate; the conical light-emitting nozzle and air path design effectively reduce splashing and strengthen the protection of the molten pool; the water-cooled copper mirror and the stable structure prevent focus drift during long-term operation. These designs together ensure the stability and purity of the molten pool in the hole, resulting in a dense and uniform cladding layer. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a laser cladding device for a small-diameter deep hole with a crack-free inner wall and high hardness alloy according to the present invention.

[0018] Figure 2 This is a schematic diagram of a laser cladding device for a high-hardness alloy with no cracks in the inner wall of a small-diameter deep hole, according to the present invention.

[0019] Figure 3 This is a schematic diagram of the gun tail assembly of a laser cladding device for a small-diameter deep hole with a crack-free, high-hardness alloy.

[0020] Figure 4 This is a schematic diagram of the main body of the laser cladding device for a high-hardness alloy with no cracks in the inner wall of a small-diameter deep hole, according to the present invention.

[0021] Figure 5 This is a schematic diagram of the gun head assembly of a laser cladding device for a small-diameter deep hole with a crack-free inner wall and high hardness alloy, according to the present invention.

[0022] Among them, 1-spindle machine tool; 2-chuck; 3-integrated heating device; 4-cladding gun; 5-slide rail; 6-roller assembly; 7-base; 8-center frame; 9-control panel; 10-three-axis transmission table; 11-gun tail assembly; 1101-optical lens mount; 1102-focusing structure; 1103-protection module; 12-gun body assembly; 13-gun head assembly; 1301-gun head body; 1302-powder feeding pipe; 1303-conical light outlet; 1304-copper mirror. Detailed Implementation

[0023] To achieve the above objectives and effects, the technical means and structure adopted by the present invention will be described in detail with reference to the accompanying drawings, focusing on the features and functions of the preferred embodiments of the present invention.

[0024] like Figures 1-5 As shown, the present invention provides a laser cladding device for high-hardness alloys with no cracks in the inner wall of small-diameter deep holes, including a base 7, a spindle machine tool 1, a three-axis transmission table 10, a cladding gun 4, an integrated heating device 3, a control panel 9, a roller assembly 6, and a center frame 8.

[0025] A slide rail 5 is installed on the base 7 along its length. The spindle machine tool 1 is fixed to one end of the base 7 by bolts. A chuck 2 is driven and connected to the spindle machine tool 1 to hold the workpiece to be processed.

[0026] The three-axis drive table 10 is mounted on the slider of the slide rail 5 and can move along the length direction of the slide rail 5 (X-axis), moving closer to or away from the main spindle machine tool 1. A vertical guide rail (Z-axis) is mounted on the three-axis drive table 10, and a horizontal guide rail is fixed on the slider of the vertical guide rail. A cladding gun 4 is mounted on the slider of the horizontal guide rail (Y-axis).

[0027] Specifically, the cladding gun 4 includes: a gun head assembly 13, a gun body assembly 12, and a gun tail assembly 11.

[0028] The tail assembly 11 includes an optical lens mount 1101, a focusing structure 1102, and a protection module 1103 connected in sequence. The optical lens mount 1101 is connected to an optical fiber and mounted on a slider of a horizontal guide rail. The focusing structure 1102 contains an optical element box adjustment ring. By driving the adjustment ring, the optical element can be slightly displaced along the optical axis, thereby achieving precise adjustment of the emitted laser spot size. The protection module 1103 contains a protective lens to protect the optical lens mount 1101 and the focusing structure 1102. The body assembly 12 is made of a metal tube, which is mounted on the protection module 1103. Multiple focusing lenses are arranged inside the metal tube along the laser transmission direction. The head assembly 13 includes a head body 1301, on which a copper mirror 1304 and a conical light-emitting nozzle 1303 are arranged. Powder feeding tubes 1302 are arranged on both sides of the conical light-emitting nozzle 1303. The powder feeding pipe 1302 is connected to a powder feeding system via a powder feeding pipeline. The powder feeding system can deliver alloy powder to the powder feeding pipe 1302 in a dry, uniform, and continuous state and then eject it. The conical light-emitting nozzle 1303 is connected to a gas supply system via a gas supply pipeline. The conical light-emitting nozzle 1303 guides inert protective gas (such as argon) along the conical surface to the molten pool area. This not only effectively suppresses alloy powder splashing and protects the copper mirror 1304, but also creates a local high-concentration inert gas environment above the molten pool, thereby preventing alloy oxidation.

[0029] Specifically, the 1304 copper mirror integrates a high-efficiency water-cooling channel to ensure minimal thermal deformation during long-term operation and prevent focus drift.

[0030] Specifically, the gun body assembly 12 is composed of multiple coaxially arranged high-temperature and corrosion-resistant metal tubes connected in sequence. Each metal tube is inlaid with a focusing lens, forming an independent optical functional segment, which facilitates quick replacement or maintenance for different inner hole depths.

[0031] In this embodiment, a support rod parallel to the cladding gun 4 is also provided on the horizontal guide rail, and an integrated heating device 3 is provided at the other end of the support rod. The integrated heating device 3 includes an induction heating coil and an infrared thermometer. The outside of the induction heating coil is wrapped with a heat insulation layer, and the induction heating coil is connected to a heating power supply. The integrated heating device 3 can achieve precise "thermal control" of the cladding area from preheating, heat tracing to slow cooling. This active thermal management strategy can effectively reduce the cooling rate, homogenize the temperature gradient, and release residual stress, ensuring that even for high-hardness and high-brittle materials such as nickel-based tungsten carbide, a completely crack-free alloy layer with good metallurgical bonding can be obtained, and the hardness of the alloy layer can be stably reached HRC55-65.

[0032] The control panel 9 is installed on the side of the base 7. It adopts a PLC control system and is equipped with a touch screen. It can display and set parameters such as spindle speed, three-axis transmission table 10 movement speed, laser power, powder feeding amount, air supply pressure, and heating temperature in real time. The control panel 9 is electrically connected to the laser emitter, focusing structure 1102, air supply system, powder feeding system, heating power supply of integrated heating device 3, and infrared thermometer of the spindle machine tool 1, three-axis transmission table 10, cladding gun 4, and integrated heating device 3 to achieve coordinated control.

[0033] In this embodiment, a roller assembly 6 and a center frame 8 are also installed on the slide rail 5. Both the rollers of the roller assembly 6 and the center frame 8 are made of high-temperature resistant metal. By adjusting the extension and retraction of the center frame 8, centering support for the workpiece can be achieved, preventing the workpiece from jumping during rotation. In actual use, as one embodiment, this device includes the following steps: S1. Pre-treatment: The tube workpiece is horizontally clamped on a precision rotary chuck. The inner wall is machined and cleaned to ensure concentricity and cleanliness of the inner and outer diameters.

[0034] S2. Overall preheating: The inner wall area of ​​the material tube to be clad is uniformly preheated to 400-600℃ to reduce the thermal shock of subsequent laser cladding.

[0035] S3, Temperature-controlled cladding: Start the laser (power 1.5-2kW), adjust the spot size to 3.5mm to accommodate high carbon content powder; simultaneously start coaxial powder feeding (powder feeding rate 7-12g / min); set the scanning speed to 300-500mm / min.

[0036] Before the laser scans to a certain point, the induction heating system provides supplementary heating to that area to ensure that the optimal melting temperature is reached.

[0037] During processing, the laser power and induction heating power can be finely adjusted according to the infrared temperature measurement feedback to ensure heat input balance and maintain the stability of the molten pool.

[0038] S4. Slow Cooling of Workpiece: After the entire inner wall cladding is completed, the laser and powder feeding stop. The integrated heating device switches to "programmed slow cooling" mode, controlling the workpiece to slowly cool to below 80°C at a set rate not exceeding 20°C / min, and then naturally air-cool to room temperature, ensuring that the cladding layer safely passes through the crack-sensitive temperature range.

[0039] S5. Post-processing: The inner wall of the cladding tube is precision bored and polished to meet the dimensional and surface finish requirements.

[0040] The above description is only a preferred embodiment of the present invention and not all embodiments. Anyone should know that structural changes made under the guidance of the present invention, and any technical solutions that are the same as or similar to the present invention, are within the protection scope of the present invention.

Claims

1. A laser cladding device for high-hardness alloys with crack-free inner walls in small-diameter deep holes, characterized in that, include: A base, on which a slide rail is provided; A spindle machine tool is mounted on the base, and a chuck is driven and connected to the spindle machine tool for clamping workpieces; A three-axis transmission table is slidably connected to the slide rail. A vertical guide rail is provided on the three-axis transmission table, and a horizontal guide rail is provided on the slider of the vertical guide rail. A cladding gun, which is mounted on the slider of the horizontal guide rail.

2. The laser cladding device for a small-diameter deep hole with crack-free inner wall and high hardness alloy as described in claim 1, characterized in that, The cladding gun includes: a gun head assembly, a gun body assembly, and a gun tail assembly; The gun tail assembly includes: An optical lens mount is mounted on the slider of the horizontal guide rail to ensure long-term stability of the optical path and to perform precise calibration of the optical path. A focusing structure is disposed on the optical lens mount and is used to adjust the size of the laser spot; A protection module is disposed at the end of the focusing structure away from the optical mount, and a protective lens is disposed within the protection module; The gun body assembly includes: a metal tube, which is disposed on the protective module and communicates with the optical lens mount, and a plurality of focusing lenses are disposed inside the metal tube; The gun head assembly includes: The gun head body is located at the end of the metal tube away from the gun tail assembly. The gun head body is provided with a conical light-emitting nozzle, a copper mirror, and a powder feeding pipe. The conical light-emitting nozzle is connected to a gas supply system for spraying gas. The powder feeding pipe is connected to a powder feeding system for spraying alloy powder.

3. The laser cladding device for a small-diameter deep hole with crack-free, high-hardness alloy as described in claim 1, characterized in that, The slider of the horizontal guide rail is also provided with a support rod parallel to the cladding gun, and the other end of the support rod is provided with an integrated heating device, which is used to heat the workpiece.

4. The laser cladding device for a small-diameter deep hole with crack-free inner wall and high hardness alloy as described in claim 3, characterized in that, The integrated heating device includes: an induction heating coil, an insulation layer provided on the outside of the induction heating coil, and an electrical connection to a heating power source.

5. The laser cladding device for a small-diameter deep hole with crack-free inner wall and high hardness alloy as described in claim 4, characterized in that, The integrated heating device also includes an infrared thermometer, which is used to detect the temperature of the workpiece.

6. The laser cladding device for a small-diameter deep hole with crack-free, high-hardness alloy as described in claim 5, characterized in that, The base is equipped with a control panel, which is electrically connected to the slide rail, the spindle machine tool, the three-axis transmission table, the cladding gun, and the integrated heating device.

7. The laser cladding device for high-hardness alloys with crack-free inner walls in small-diameter deep holes as described in any one of claims 1-6, characterized in that, The slide rail is also slidably connected to a roller assembly and a center frame.

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