Laser synchronous auxiliary titanium alloy ion nitriding device and process

Abstract

The invention discloses a laser synchronous auxiliary titanium alloy ion nitriding device which comprises an ion nitriding furnace and a laser processor. The ion nitriding furnace comprises a base and a bell jar type furnace body, a rotating shaft is mounted on a chassis of the base, and a cathode screw connected with a cathode disc is mounted in the rotating shaft; an observation window is formed in one side of the bell jar type furnace body; the laser processor comprises a laser generator; the nitriding process comprises the following steps: 1, treating a titanium alloy workpiece; 2, nitriding treatment; and 3, laser-assisted nitriding treatment is completed. According to the device disclosed by the invention, the laser processor is matched with the ion nitriding furnace, and the quartz glass is mounted on the ion nitriding furnace, so that laser penetrates through the quartz glass to irradiate a titanium alloy workpiece, laser-assisted treatment is performed while ion nitriding is realized, a hard shell layer structure appearing on the surface of ion nitriding is eliminated, and the service life of the titanium alloy workpiece is prolonged. The ion nitriding layer thickness and the nitriding layer section hardness are improved, and high-temperature deformation is reduced; the method is simple in process, high in efficiency and suitable for surface treatment of high-end precision parts.

Description

Technical Field

[0001] The invention belongs to the technical field of surface modification, and in particular relates to a laser synchronous assisted titanium alloy ion nitriding device and process. Background Art

[0002] Titanium alloy has the advantages of low density, high specific strength, good corrosion resistance, high high temperature strength, good creep resistance and oxidation resistance. Combined with the development requirements of "lightweight" in weapons and equipment in recent years, the use of titanium alloy materials to replace key steel parts in the fields of aviation, aerospace, weapons, etc. has become the main way to achieve the goal of reducing the weight of weapons and equipment. However, the low hardness, poor wear resistance and poor oxidation resistance of titanium alloy seriously restrict its application as a structural material in the field of national defense and military industry.

[0003] As a surface strengthening technology, titanium alloy ion nitriding technology has the advantages of high activity, fast penetration rate, and easier to reach a deeper nitriding layer due to the bombardment effect of ions on the surface of titanium alloy. The treated nitriding layer has good bonding strength with the matrix, no subsequent processing and nitriding layer defects, and the surface state is complete. The surface layer is in a compressive stress state, which can significantly improve the friction, wear and fretting fatigue performance. However, due to the shallow nitriding layer of titanium alloy, this technology is currently only used on light-loaded structural parts.

[0004] At present, there is a "hard shell" structure on the surface of titanium alloy ion nitriding. This is because during the high-temperature ion nitriding process, a large number of nitrogen ions gather on the surface of the titanium alloy in the early stage of nitriding, resulting in an increase in nitrogen potential. When the temperature rises, the nitrogen ions react with the Ti on the surface of the titanium alloy, and a hardened layer mainly composed of TiN is quickly formed on the surface. The existence of this hardened layer prevents the nitrogen ions from further diffusing into the interior of the titanium alloy, thereby causing the ion nitriding layer to become thinner, and the hardness of the cross-section of the nitriding layer drops significantly below the hardened layer, which seriously affects the application of titanium alloys in aerospace and other fields. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a laser synchronous assisted titanium alloy ion nitriding device in view of the deficiencies of the above-mentioned prior art. The device is equipped with a laser processor for the ion nitriding furnace, and an observation window is opened on one side of the ion nitriding furnace and quartz glass is installed, so that the laser in the laser processor is irradiated on the titanium alloy workpiece in the furnace through the quartz glass, thereby realizing the simultaneous laser-assisted treatment of the ion nitriding of the titanium alloy workpiece, effectively eliminating the "hard shell layer" structure appearing on the ion nitriding surface, thereby increasing the thickness of the ion nitriding layer and the hardness of the nitriding layer cross section, and solving the problems of the "hard shell layer" structure on the titanium alloy surface produced by a single ion nitriding process, the uneven nitriding layer of a large workpiece, and the deformation caused by the high nitriding temperature.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a laser synchronous assisted titanium alloy ion nitriding device, characterized in that it includes an ion nitriding furnace and a matching laser processor;

[0007] The ion nitriding furnace comprises a base and a bell-shaped furnace body installed on the base, the base comprises a bracket and a chassis welded on the bracket, the chassis is respectively connected with a chassis circulating water inlet and a chassis circulating water outlet, and the chassis is also provided with an exhaust hole connected to the bell-shaped furnace body and a connection hole for thermocouples to connect to the bell-shaped furnace body, a rotating shaft is installed through the center of the chassis, a cathode screw is installed in the rotating shaft, one end of the cathode screw extends into the bell-shaped furnace body and is connected to the cathode disk, and the other end extends out of the bell-shaped furnace body and is connected to the negative pole of the power supply, the cathode disk is located in the bell-shaped furnace body, and the bell-shaped furnace body is connected to the positive pole of the power supply;

[0008] The bell-shaped furnace body is connected with a gas joint, and the gas joint is connected with a gas source, a gas flow control valve is installed on the connecting pipeline between the gas joint and the gas source, the bell-shaped furnace body is also respectively connected with a furnace body circulating water inlet and a furnace body circulating water outlet, an observation window is opened on one side of the bell-shaped furnace body, and a quartz glass is fixedly installed in the card slot of the observation window;

[0009] The laser processor comprises a laser generator installed on a mechanical arm, the laser generator is connected with a laser head, and the laser head faces the quartz glass.

[0010] The above-mentioned laser synchronous assisted titanium alloy ion nitriding device is characterized in that a lifting buckle is installed on the top of the bell-shaped furnace body.

[0011] The above-mentioned laser synchronous assisted titanium alloy ion nitriding device is characterized in that the quartz glass is fixed in the slot of the observation window by a sealing ring and a tightening device.

[0012] At the same time, the present invention also discloses a process for laser synchronous assisted titanium alloy ion nitriding using the above device, characterized in that the process comprises the following steps:

[0013] Step 1: preparing a titanium alloy workpiece by wire cutting, and performing surface grinding to obtain a processed titanium alloy workpiece;

[0014] Step 2, placing the titanium alloy workpiece after the treatment in step 1 in the cathode disk and facing the observation window, using a hydraulic pump to lift the bell-shaped furnace body and then fasten it on the base, connecting the bell-shaped furnace body to the positive pole of the power supply, connecting the cathode screw to the negative pole of the power supply, using a vacuum pump to evacuate the bell-shaped furnace body, and then turning on the power supply, introducing nitrogen into the bell-shaped furnace body through the gas connector, and setting the nitriding treatment process parameters including the heating rate, nitriding temperature and holding time, nitriding voltage, and holding gas pressure, and starting the nitriding treatment on the surface of the titanium alloy workpiece;

[0015] Step three, use a thermocouple to measure the temperature in the bell-shaped furnace during the nitriding treatment process in step two. When the set nitriding temperature is reached, it enters the insulation stage, starts the laser generator, and moves the robotic arm so that the laser emitted by the laser head enters the bell-shaped furnace through the quartz glass to perform laser treatment on the titanium alloy workpiece, thereby assisting the titanium alloy workpiece in completing the nitriding treatment.

[0016] The above process is characterized in that the nitriding treatment process parameters in step 2 are: heating rate 3°C / min~5°C / min, nitriding temperature 820°C~880°C, holding time 6h~10h, nitriding voltage 800V~900V, and holding gas pressure 160Pa~240Pa.

[0017] The above process is characterized in that the laser head in step three is facing the quartz glass and is 3 cm to 5 cm away from the surface of the quartz glass, and the laser beam passes through the quartz glass and directly hits the surface of the titanium alloy workpiece.

[0018] The above process is characterized in that the quartz glass in step three has a thickness of 25 mm to 30 mm, a refractive index of 1.516, and a light transmittance of 98%.

[0019] The above process is characterized in that the laser in step three is a fiber laser with a wavelength of 1064nm, a pulse width of 10ns to 20ns, a focal length of 300mm to 400mm, a spot diameter of 0.5mm to 1mm, and a circular spot shape.

[0020] The above process is characterized in that the power of the laser treatment in step three is 0.8kW to 1.2kW, the scanning mode is "Z"-shaped continuous scanning, the scanning speed is 8mm / s to 12mm / s, and the scanning interval is 5min.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The laser synchronous assisted titanium alloy ion nitriding device of the present invention is equipped with a laser processor on the basis of an ion nitriding furnace, and an observation window is opened on one side of the ion nitriding furnace and quartz glass is installed, so that the laser in the laser processor is irradiated through the quartz glass onto the titanium alloy workpiece in the furnace, thereby realizing the simultaneous laser-assisted treatment of the titanium alloy workpiece during ion nitriding, and utilizing the high energy of the laser to effectively eliminate the "hard shell layer" structure appearing on the surface of the ion nitriding, thereby increasing the thickness of the ion nitriding layer and the hardness of the cross-section of the nitriding layer, realizing high-quality and high-efficiency ion nitriding, and improving the slow efficiency of ion nitriding, thin nitriding layer, and low cross-sectional hardness.

[0023] 2. The laser synchronous assisted titanium alloy ion nitriding device of the present invention rotates the titanium alloy workpiece by installing a rotating shaft at the center of the chassis and a cathode screw connected to the cathode disk holding the titanium alloy workpiece, which is beneficial to the uniform distribution of ion flow on the surface of the titanium alloy workpiece during ion nitriding, thereby achieving uniform nitriding or local nitriding of the surface of a larger workpiece, and is particularly suitable for barrels, cylindrical or special-shaped parts.

[0024] 3. In the laser synchronous assisted titanium alloy ion nitriding device of the present invention, a mechanical arm is set to drive the laser processor to move to adjust the laser irradiation position, thereby realizing laser synchronous assisted nitriding of specific areas or local areas on the workpiece surface, reducing subsequent processing steps of the workpiece and reducing processing scrap rate.

[0025] 4. The present invention utilizes the local high energy and heating block characteristics of laser synchronous assisted processing to rapidly increase the surface temperature of the titanium alloy workpiece to the nitriding temperature, while the internal temperature of the workpiece is relatively low, thereby effectively reducing the high-temperature deformation of the titanium alloy workpiece and realizing low-temperature ion nitriding.

[0026] 5. The laser synchronous assisted titanium alloy ion nitriding device of the present invention has a simple structure, convenient operation, and high preparation efficiency, and meets the needs of surface treatment of high-end precision parts.

[0027] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of the laser synchronous assisted titanium alloy ion nitriding device of the present invention.

[0029] Figure 2 This is a cross-sectional metallographic photograph of the wear-resistant coating without a “hard shell layer” structure prepared on the surface of a titanium alloy workpiece in Example 3 of the present invention.

[0030] Description of Reference Numerals

[0031] 1—gas flow control valve; 2—gas connector; 3—bell-shaped furnace body;

[0032] 4-1—Chassis circulating water inlet; 4-2—Chassis circulating water outlet; 5—Thermocouple;

[0033] 6—cathode screw; 7—rotating axis; 8—lifting buckle;

[0034] 9—cathode disk; 10—quartz glass; 11—observation window;

[0035] 12—Laser head; 13—Laser generator; 14—Robotic arm;

[0036] 15-1—Furnace body circulating water inlet; 15-2—Furnace body circulating water outlet. DETAILED DESCRIPTION

[0037] The laser synchronous assisted titanium alloy ion nitriding device of the present invention is described in detail through Example 1.

[0038] Example 1

[0039] like Figure 1 As shown, the laser synchronous assisted titanium alloy ion nitriding device of this embodiment includes an ion nitriding furnace and a matching laser processor;

[0040] The ion nitriding furnace includes a base and a bell-shaped furnace body 3 installed on the base, the base includes a bracket and a chassis welded on the bracket, the chassis is respectively connected with a chassis circulating water inlet 4-1 and a chassis circulating water outlet 4-2, and the chassis is also provided with an exhaust hole connected to the bell-shaped furnace body 3 and a connection hole for a thermocouple 5 to be connected to the bell-shaped furnace body 3, a rotating shaft 7 is installed through the center of the chassis, a cathode screw 6 is installed in the rotating shaft 7, one end of the cathode screw 6 extends into the bell-shaped furnace body 3 and is connected to the cathode disk 9, and the other end extends out of the bell-shaped furnace body 3 and is connected to the negative pole of the power supply, the cathode disk 9 is located in the bell-shaped furnace body 3, and the bell-shaped furnace body 3 is connected to the positive pole of the power supply;

[0041] The bell-shaped furnace body 3 is connected with a gas connector 2, and the gas connector 2 is connected to a gas source, and a gas flow control valve 1 is installed on the connecting pipeline between the gas connector 2 and the gas source. The bell-shaped furnace body 3 is also respectively connected with a furnace body circulating water inlet 15-1 and a furnace body circulating water outlet 15-2. An observation window 11 is provided on one side of the bell-shaped furnace body 3, and a quartz glass 10 is fixedly installed in the card slot of the observation window 11;

[0042] The laser processor includes a laser generator 13 mounted on a mechanical arm 14 . A laser head 12 is connected to the laser generator 13 , and the laser head 12 faces the quartz glass 10 .

[0043] In the nitriding device of this embodiment, an ion nitriding furnace is provided for ion nitriding of the titanium alloy, and a matching laser processor is provided to perform auxiliary laser processing during the ion nitriding process of the titanium alloy, so as to utilize the high energy characteristics of the laser to eliminate the hardened layer mainly composed of TiN generated by the reaction of nitrogen ions with Ti on the surface of the titanium alloy, i.e., the "hard shell layer" structure;

[0044] Specifically, the ion nitriding furnace in the nitriding device of this embodiment includes two parts: a base and a bell-shaped furnace body installed on the base, wherein the base is used as a load-bearing component, and the bell-shaped furnace body is used as a place for laser-assisted ion nitriding of titanium alloy workpieces. By setting the ion nitriding furnace as a split structure, it is convenient to control the base and the bell-shaped furnace body separately, and by moving the bell-shaped furnace body, it is convenient to load and remove the titanium alloy workpiece;

[0045] In this embodiment, the chassis is welded to the bracket to form a base, which simplifies the device structure and improves the overall stability of the nitriding device. The chassis circulating water inlet 4-1 and the chassis circulating water outlet 4-2 are respectively connected to the chassis, and flowing water is introduced into the chassis through the chassis circulating water inlet 4-1 by a circulating pump, and sent out through the chassis circulating water outlet 4-2 to cool the chassis, so as to avoid excessive chassis temperature during ion nitriding, which may cause nitrogen ions to react with Ti to form a hardened layer. In this embodiment, an exhaust hole connected to the bell-shaped furnace body 3 is opened on the chassis, and a vacuum pump is connected to the exhaust hole to evacuate the bell-shaped furnace body 3 to provide vacuum conditions for ion nitriding. At the same time, a connection hole for connecting the thermocouple 5 to the bell-shaped furnace body 3 is opened on the chassis, and the temperature in the bell-shaped furnace body 3 is measured by the thermocouple 5, so as to accurately control the temperature of the ion nitriding process and timely control the starting node of the laser treatment, thereby ensuring the effect of laser-assisted elimination of the hardened layer produced by ion nitriding. A rotating shaft 7 is installed through the center position, a cathode screw 6 is installed in the rotating shaft 7, and one end of the cathode screw 6 extends into the bell-shaped furnace body 3 and is connected to the cathode disk 9. The rotating function of the rotating shaft 7 is used to drive the cathode screw 6 to rotate, and then drive the cathode disk 9 containing the titanium alloy workpiece in the bell-shaped furnace body 3 to rotate, which is beneficial to the uniform distribution of ion flow on the surface of the titanium alloy workpiece during ion nitriding, and is particularly suitable for cylinders, cylindrical or special-shaped parts. At the same time, it is convenient to present a specific surface area of ​​the titanium alloy workpiece in the laser processing area through rotation, thereby improving the convenience of laser-assisted synchronous ion nitriding; in addition, in this embodiment, the other end of the cathode screw 6 is extended out of the bell-shaped furnace body 3 and connected to the negative pole of the power supply, and the bell-shaped furnace body 3 is connected to the positive pole of the power supply, thereby forming an electric field between the furnace body 3 and the cathode disk 9, and the electric field ionizes nitrogen to produce nitrogen ions. The nitrogen ions will bombard the titanium alloy workpiece to be nitrided placed on the cathode disk 9 due to the action of the electric field, thereby achieving nitriding and ensuring the smooth progress of the ion nitriding process.

[0046] In the nitriding device of the present embodiment, a gas connector 2 is connected to the bell-shaped furnace body 3, and the gas connector 2 is connected to the gas source, so that during the ion nitriding process, nitriding gas such as nitrogen is sent into the bell-shaped furnace body 3 through the gas connector 2, and converted into an ion flow to act on the titanium alloy workpiece placed on the cathode disk 9 in the bell-shaped furnace body 3 to achieve ion nitriding. A gas flow control valve 1 is installed on the connecting pipeline between the gas connector 2 and the gas source to control the flow rate of the nitriding gas to adjust the ion nitriding process; a furnace body circulating water inlet 15-1 and a furnace body circulating water outlet 15-2 are respectively connected to the bell-shaped furnace body 3, and a circulating pump is used to pump water from the furnace body circulating water inlet 15-1 to the furnace wall of the bell-shaped furnace body 3. Flowing water is introduced into the bell-shaped furnace body 3 and sent out through the furnace body circulating water outlet 15-2 to cool the bell-shaped furnace body 3 to avoid excessive temperature of the bell-shaped furnace body 3 during ion nitriding, which may cause nitrogen ions to react with Ti to form a hardened layer. In this embodiment, an observation window 11 is opened on one side of the bell-shaped furnace body 3, and a quartz glass 10 is fixedly installed in the slot of the observation window 11 as a laser processing channel, so that the laser penetrates the quartz glass and enters the bell-shaped furnace body 3 to act on the titanium alloy workpiece during the nitriding process, thereby achieving the effect of laser synchronous auxiliary ion nitriding, and the effect of laser synchronous auxiliary can be regulated by adjusting the size and shape of the observation window 11 and the thickness, refractive index, transmittance and other parameters of the quartz glass 10.

[0047] The laser processor in the nitriding device of this embodiment is provided with a laser generator 13, and the laser generator 13 is connected to a laser head 12, and the laser head 12 is facing the quartz glass 10, and is used to generate and emit laser through the quartz glass 10 into the bell-shaped furnace body 3 to act on the titanium alloy workpiece. The laser spot diameter and shape and other parameters can be changed by replacing the laser head to meet the surface treatment requirements of different laser-assisted nitriding. By installing the laser generator 13 on the mechanical arm 14, the movement of the mechanical arm 14 is used to accurately control the laser action area of ​​the laser generator 13, thereby realizing laser synchronous assisted nitriding of specific areas or local areas on the titanium alloy surface. Usually, a laser control system is used to control the movement of the mechanical arm 14 and the laser parameters of the laser generator 13. The commonly used laser control system model is P-ECS-3000 / 35, which is purchased from Aachen United Technology (Tianjin) Co., Ltd.

[0048] Furthermore, a lifting buckle 8 is installed at the top of the bell-shaped furnace body 3 in this embodiment. By installing the lifting buckle 8 at the top of the bell-shaped furnace body 3, it is convenient to use a hydraulic pump to act on the lifting buckle 8, so as to lift or lower the bell-shaped furnace body 3 and fasten it to the base, which is convenient for putting in and taking out titanium alloy workpieces, especially large-sized titanium alloy workpieces.

[0049] Furthermore, in this embodiment, the quartz glass 10 is fixed in the slot of the observation window 11 by a sealing ring and a tightening device. Through the action of the sealing ring and the tightening device such as a locking nut, the quartz glass 10 is firmly fixed in the slot, ensuring the sealing inside the bell-shaped furnace body 3.

[0050] The laser synchronous assisted titanium alloy ion nitriding process of the present invention is described in detail through Examples 2 to 4.

[0051] Example 2

[0052] The process of laser synchronous assisted titanium alloy ion nitriding in this embodiment includes the following steps:

[0053] Step 1: Prepare a titanium alloy workpiece with a rectangular thin block of 60 mm × 60 mm × 20 mm in size (length × width × height) by wire cutting, and polish the surface with 240#, 400#, 800#, and 1200# metallographic sandpaper to remove the surface oxide film and scratches, place it in an ethanol solution for ultrasonic cleaning for 20 minutes, rinse it with deionized water, and blow it dry with an air gun to obtain a treated titanium alloy workpiece;

[0054] Step 2, place the titanium alloy workpiece after the treatment in step 1 stably in the cathode disk 9 and face the observation window 11, use a hydraulic pump to lift the bell-shaped furnace body 3 and fasten it on the base, connect the bell-shaped furnace body 3 to the positive pole of the power supply, connect the cathode screw 6 to the negative pole of the power supply, use a vacuum pump to evacuate the bell-shaped furnace body 3, and then turn on the power supply, and introduce nitrogen into the bell-shaped furnace body 3 by connecting the gas connector 2, and set the nitriding treatment process parameters including the heating rate, nitriding temperature and holding time, nitriding voltage, and holding pressure, and start nitriding treatment on the surface of the titanium alloy workpiece, the heating rate of the nitriding treatment is 3°C / min, the nitriding temperature is 820°C, the holding time is 6h, the nitriding voltage is 800V, and the holding pressure is 160Pa;

[0055] Step 3: Use a thermocouple 5 to measure the temperature in the bell-shaped furnace body 3 during the nitriding treatment process in step 2. When the set nitriding temperature is reached, the temperature is kept at a constant temperature. Start the laser generator 13, move the mechanical arm 14 so that the laser head 12 is facing the quartz glass 10, and is 3 cm away from the surface of the quartz glass 10 and 350 mm away from the surface of the titanium alloy workpiece. The emitted laser enters the bell-shaped furnace body 3 through the quartz glass 10 and directly hits the area of ​​40 mm × 40 mm on the surface of the titanium alloy workpiece. The gold workpiece is laser treated to assist the titanium alloy workpiece in completing nitriding treatment; the thickness of the quartz glass 10 is 25 mm, the refractive index is 1.516, and the transmittance is 98%; the laser is a fiber laser with a wavelength of 1064 nm, a pulse width of 10 ns, a focal length of 300 mm, a spot diameter of 0.8 mm, and a circular spot shape; the power of the laser treatment is 0.8 kW, the scanning mode is "Z"-shaped continuous scanning, the scanning speed is 12 mm / s, and the scanning interval is 5 min.

[0056] After testing, the wear-resistant coating without a "hard shell layer" structure prepared on the surface of the titanium alloy workpiece in this embodiment has a thickness of 60 μm and a surface hardness of 860 HV. 0.1 The surface is smooth and free of impurities, and the workpiece is basically free of deformation.

[0057] Example 3

[0058] The process of laser synchronous assisted titanium alloy ion nitriding in this embodiment includes the following steps:

[0059] Step 1: Prepare a titanium alloy workpiece with a rectangular thin block of 60 mm × 60 mm × 20 mm in size (length × width × height) by wire cutting, and polish the surface with 240#, 400#, 800#, and 1200# metallographic sandpaper to remove the surface oxide film and scratches, place it in an ethanol solution for ultrasonic cleaning for 20 minutes, rinse it with deionized water, and blow it dry with an air gun to obtain a treated titanium alloy workpiece;

[0060] Step 2, place the titanium alloy workpiece after the treatment in step 1 stably in the cathode disk 9 and face the observation window 11, use a hydraulic pump to lift the bell-shaped furnace body 3 and fasten it on the base, connect the bell-shaped furnace body 3 to the positive pole of the power supply, connect the cathode screw 6 to the negative pole of the power supply, use a vacuum pump to evacuate the bell-shaped furnace body 3, and then turn on the power supply, and introduce nitrogen into the bell-shaped furnace body 3 by connecting the gas connector 2, and set the nitriding treatment process parameters including the heating rate, nitriding temperature and holding time, nitriding voltage, and holding pressure, and start nitriding treatment on the surface of the titanium alloy workpiece, the heating rate of the nitriding treatment is 4°C / min, the nitriding temperature is 850°C, the holding time is 8h, the nitriding voltage is 850V, and the holding pressure is 200Pa;

[0061] Step 3, using a thermocouple 5 to measure the temperature in the bell-shaped furnace body 3 during the nitriding treatment process in step 2, when the set nitriding temperature is reached, the insulation stage is entered, the laser generator 13 is started, and the mechanical arm 14 is moved so that the laser head 12 is facing the quartz glass 10, and is 4 cm away from the surface of the quartz glass 10, and is 450 mm away from the surface of the titanium alloy workpiece. The emitted laser enters the bell-shaped furnace body 3 through the quartz glass 10 and directly shines on the surface of the titanium alloy workpiece. The length × width is 40 mm × 40 mm, the titanium alloy workpiece is laser treated, and the titanium alloy workpiece is assisted to complete the nitriding treatment; the thickness of the quartz glass 10 is 28 mm, the refractive index is 1.516, and the transmittance is 98%; the laser is a fiber laser with a wavelength of 1064 nm, a pulse width of 15 ns, a focal length of 350 mm, a spot diameter of 0.8 mm, and a circular spot shape; the power of the laser treatment is 1 kW, the scanning mode is "Z"-shaped continuous scanning, the scanning speed is 10 mm / s, and the scanning interval is 5 min.

[0062] After testing, the wear-resistant coating without a "hard shell layer" structure prepared on the surface of the titanium alloy workpiece in this embodiment has a thickness of 90 μm and a surface hardness of 910 HV. 0.1 The surface is smooth and free of impurities, and the workpiece is basically free of deformation.

[0063] Figure 2 This is a cross-sectional metallographic photograph of the wear-resistant coating without a "hard shell layer" structure prepared on the surface of the titanium alloy workpiece in this embodiment. Figure 2 It can be seen that there are no long and grown crystals on the surface of the wear-resistant coating, i.e., the nitriding layer, and they are basically round equiaxed crystals.

[0064] Example 4

[0065] The process of laser synchronous assisted titanium alloy ion nitriding in this embodiment includes the following steps:

[0066] Step 1: Prepare a titanium alloy workpiece with a rectangular thin block of 60 mm × 60 mm × 20 mm in size (length × width × height) by wire cutting, and polish the surface with 240#, 400#, 800#, and 1200# metallographic sandpaper to remove the surface oxide film and scratches, place it in an ethanol solution for ultrasonic cleaning for 20 minutes, rinse it with deionized water, and blow it dry with an air gun to obtain a treated titanium alloy workpiece;

[0067] Step 2, place the titanium alloy workpiece after the treatment in step 1 stably in the cathode disk 9 and face the observation window 11, use a hydraulic pump to lift the bell-shaped furnace body 3 and then fasten it on the base, connect the bell-shaped furnace body 3 to the positive pole of the power supply, connect the cathode screw 6 to the negative pole of the power supply, use a vacuum pump to evacuate the bell-shaped furnace body 3, and then turn on the power, and introduce nitrogen into the bell-shaped furnace body 3 by connecting the gas connector 2, and set the nitriding treatment process parameters including the heating rate, nitriding temperature and holding time, nitriding voltage, and holding pressure, and start nitriding treatment on the surface of the titanium alloy workpiece, the heating rate of the nitriding treatment is 5°C / min, the nitriding temperature is 880°C, the holding time is 10h, the nitriding voltage is 900V, and the holding pressure is 240Pa;

[0068] Step 3, using a thermocouple 5 to measure the temperature in the bell-shaped furnace body 3 during the nitriding treatment process in step 2, when the set nitriding temperature is reached, the insulation stage is entered, the laser generator 13 is started, and the mechanical arm 14 is moved so that the laser head 12 is facing the quartz glass 10, and is 5 cm away from the surface of the quartz glass 10, and is 550 mm away from the surface of the titanium alloy workpiece. The emitted laser enters the bell-shaped furnace body 3 through the quartz glass 10 and directly shines on the surface of the titanium alloy workpiece. The length × width is 40 mm × 40 mm, the titanium alloy workpiece is laser treated, and the titanium alloy workpiece is assisted to complete the nitriding treatment; the thickness of the quartz glass 10 is 30 mm, the refractive index is 1.516, and the transmittance is 98%; the laser is a fiber laser with a wavelength of 1064 nm, a pulse width of 20 ns, a focal length of 400 mm, a spot diameter of 1 mm, and a circular spot shape; the power of the laser treatment is 1.2 kW, the scanning mode is "Z"-shaped continuous scanning, the scanning speed is 12 mm / s, and the scanning interval is 5 min.

[0069] After testing, the wear-resistant coating without a "hard shell layer" structure prepared on the surface of the titanium alloy workpiece in this embodiment has a thickness of 80 μm and a surface hardness of 890 HV. 0.1 The surface is smooth and free of impurities, and the workpiece is only slightly deformed.

[0070] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A laser synchronous assisted titanium alloy ion nitriding device, characterized in that: Includes ion nitriding furnace and matching laser processor; The ion nitriding furnace comprises a base and a bell-shaped furnace body (3) mounted on the base, the base comprises a bracket and a chassis welded on the bracket, the chassis is respectively connected with a chassis circulating water inlet (4-1) and a chassis circulating water outlet (4-2), and the chassis is also provided with an exhaust hole connected to the bell-shaped furnace body (3) and a connection hole for a thermocouple (5) to be connected to the bell-shaped furnace body (3), a rotating shaft (7) is installed through the center of the chassis, a cathode screw (6) is installed in the rotating shaft (7), one end of the cathode screw (6) extends into the bell-shaped furnace body (3) and is connected to a cathode disk (9), and the other end extends out of the bell-shaped furnace body (3) and is connected to a negative pole of a power source, the cathode disk (9) is located in the bell-shaped furnace body (3), and the bell-shaped furnace body (3) is connected to a positive pole of the power source; The bell-shaped furnace body (3) is connected to a gas connector (2), and the gas connector (2) is connected to a gas source. A gas flow control valve (1) is installed on the connecting pipeline between the gas connector (2) and the gas source. The bell-shaped furnace body (3) is also respectively connected to a furnace body circulating water inlet (15-1) and a furnace body circulating water outlet (15-2). An observation window (11) is provided on one side of the bell-shaped furnace body (3), and a quartz glass (10) is fixedly installed in a slot of the observation window (11); The laser processor comprises a laser generator (13) mounted on a mechanical arm (14); a laser head (12) is connected to the laser generator (13), and the laser head (12) faces the quartz glass (10).

2. The laser synchronous assisted titanium alloy ion nitriding device according to claim 1 is characterized in that: A lifting buckle (8) is installed on the top of the bell-shaped furnace body (3).

3. The laser synchronous assisted titanium alloy ion nitriding device according to claim 1 is characterized in that: The quartz glass (10) is fixed in the slot of the observation window (11) via a sealing ring and a tightening device.

4. A process for laser synchronous assisted titanium alloy ion nitriding using the device as claimed in any one of claims 1 to 3, characterized in that: The process includes the following steps: Step 1: preparing a titanium alloy workpiece by wire cutting, and performing surface grinding to obtain a processed titanium alloy workpiece; Step 2, placing the titanium alloy workpiece after the treatment in step 1 in the cathode disk (9) and facing the observation window (11), using a hydraulic pump to lift the bell-shaped furnace body (3) and then fasten it on the base, connecting the bell-shaped furnace body (3) to the positive electrode of the power supply, connecting the cathode screw (6) to the negative electrode of the power supply, using a vacuum pump to evacuate the bell-shaped furnace body (3), then turning on the power supply, and introducing nitrogen into the bell-shaped furnace body (3) through the gas connector (2), and setting the nitriding treatment process parameters including the heating rate, nitriding temperature and holding time, nitriding voltage, and holding gas pressure, and starting the nitriding treatment on the surface of the titanium alloy workpiece; Step 3: Using a thermocouple (5) to measure the temperature in the bell-shaped furnace body (3) during the nitriding treatment process in step 2, when the set nitriding temperature is reached, the temperature is kept at a constant temperature, the laser generator (13) is started, and the mechanical arm (14) is moved so that the laser emitted by the laser head (12) enters the bell-shaped furnace body (3) through the quartz glass (10) to perform laser treatment on the titanium alloy workpiece, thereby assisting the titanium alloy workpiece in completing the nitriding treatment.

5. The process according to claim 4, characterized in that The nitriding treatment process parameters in step 2 are: heating rate 3°C / min~5°C / min, nitriding temperature 820°C~880°C, holding time 6h~10h, nitriding voltage 800V~900V, and holding gas pressure 160Pa~240Pa.

6. The process according to claim 4, characterized in that In step 3, the laser head (12) is facing the quartz glass (10) and is 3 cm to 5 cm away from the surface of the quartz glass (10). The laser beam passes through the quartz glass (10) and is directly projected onto the surface of the titanium alloy workpiece.

7. The process according to claim 4, characterized in that The quartz glass (10) in step 3 has a thickness of 25 mm to 30 mm, a refractive index of 1.516, and a light transmittance of 98%.

8. The process according to claim 4, characterized in that The laser in step three is a fiber laser with a wavelength of 1064nm, a pulse width of 10ns to 20ns, a focal length of 300mm to 400mm, a spot diameter of 0.5mm to 1mm, and a circular spot shape.

9. The process according to claim 4, characterized in that The power of the laser treatment in step 3 is 0.8 kW to 1.2 kW, the scanning mode is "Z"-shaped continuous scanning, the scanning speed is 8 mm / s to 12 mm / s, and the scanning interval is 5 minutes.

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