阅读说明：本技术 一种同步超声喷丸辅助制备无缺陷耐磨蚀涂层的方法 (Method for preparing defect-free wear-resistant corrosion-resistant coating by synchronous ultrasonic shot blasting ) 是由 张泽雄 陈飞文 杨桂勉 张家宽 吴震海 郑创伟 王鹏 陈余 唐健 于 2021-08-04 设计创作，主要内容包括：本发明公开了一种同步超声喷丸辅助制备无缺陷耐磨蚀涂层的方法。其具体包括如下具体步骤：将待加工轴试样固定于集成化加工平台上,进行表面清理除锈处理；将待熔覆粉末进行烘烤去湿,并装入同步送粉器中；设定高速激光熔覆参数及熔覆头平移速率；调节移动同步超声喷丸系统中的移动控制器,使喷丸腔正好位于熔覆头正下方与熔覆头处于同一水平面,平移速率相同且进行同向移动；同时开启高速激光熔覆系统和超声喷丸辅助系统,直至熔覆过程结束获得无缺陷的耐磨蚀涂层。本发明的有益效果：本发明所制备的高速激光熔覆耐磨蚀涂层内部及界面处无明显的宏微观缺陷,涂层的晶粒明显细化且硬度提高,涂层的耐磨蚀性能和服役寿命均显著提高。(The invention discloses a method for preparing a defect-free wear-resistant corrosion-resistant coating by synchronous ultrasonic shot blasting. The method specifically comprises the following specific steps: fixing a shaft sample to be processed on the integrated processing platform, and carrying out surface cleaning and rust removing treatment; baking and dehumidifying the powder to be clad, and filling the powder into a synchronous powder feeder; setting high-speed laser cladding parameters and the translation rate of a cladding head; adjusting a moving controller in the moving synchronous ultrasonic shot blasting system to ensure that the shot blasting cavity is just positioned under the cladding head and is positioned on the same horizontal plane with the cladding head, the translation rates are the same, and the shot blasting cavity moves in the same direction; and simultaneously starting a high-speed laser cladding system and an ultrasonic shot blasting auxiliary system until the cladding process is finished to obtain a defect-free abrasion-resistant coating. The invention has the beneficial effects that: the high-speed laser cladding abrasion-resistant coating prepared by the invention has no obvious macro-micro defects in the interior and at the interface, the crystal grains of the coating are obviously refined, the hardness is improved, and the abrasion resistance and the service life of the coating are obviously improved.)

1. A method for preparing a defect-free wear-resistant corrosion-resistant coating by synchronous ultrasonic shot blasting assistance is characterized in that a synchronous ultrasonic shot blasting assistance system is added on the basis of a high-speed laser cladding technology, and the method comprises the following specific steps:

s1: fixing a shaft sample to be processed on the integrated processing platform, and carrying out surface cleaning and rust removing treatment;

s2: baking and dehumidifying the powder to be clad, and filling the powder into a synchronous powder feeder;

s3: setting high-speed laser cladding parameters and setting the translation rate of a cladding head;

s4: adjusting a movement controller in the movement synchronous ultrasonic shot blasting system to enable a shot blasting cavity to be just positioned under a cladding head and to be positioned on the same horizontal plane with the cladding head, and setting the translation rate of the ultrasonic shot blasting auxiliary system to be the same as that of the cladding head in the cladding process and enabling the ultrasonic shot blasting auxiliary system to move in the same direction;

s5: and starting a high-speed laser cladding system, preparing a cladding coating on the surface of the sample, simultaneously starting an ultrasonic shot blasting auxiliary system, and carrying out synchronous ultrasonic shot blasting reinforcement treatment on the deposited coating until the cladding process is finished to obtain a defect-free abrasion-resistant coating.

2. The method for preparing a defect-free abrasion-resistant coating layer by the aid of synchronous ultrasonic shot blasting according to claim 1, wherein the surface cleaning and rust removing treatment in the step S1 is to remove surface rust and stains by using sand paper or a grinding wheel.

3. The method for preparing a defect-free abrasion-resistant coating by the aid of synchronous ultrasonic shot blasting according to claim 1, wherein the cladding powder in the step S2 has a particle size range of 10-200 μm, the baking and dehumidifying process is carried out in a vacuum drying oven, the baking temperature is 120-150 ℃, and the baking time is 20-60 min.

4. The method for preparing a defect-free abrasion-resistant coating by the aid of synchronous ultrasonic shot blasting according to claim 1, wherein the process parameters of high-speed laser cladding in the step S3 are as follows: the laser power is 0-6 KW, the distance between cladding and the surface of the sample is 10-16 mm, the cladding speed is 500-50000 mm/min, and the powder feeding speed is 0-5 r/min.

5. The method for preparing a defect-free abrasion-resistant coating by the aid of synchronous ultrasonic shot peening according to claim 1, wherein the process parameters of the synchronous ultrasonic shot peening in the step S3 are as follows: the frequency of the ultrasonic generator is 0-20 kHz, the diameter of the shot blasting steel ball is 1-5 mm, and the distance between the surface of the workpiece and the vibration head is 3-15 mm, so that proper impact action on the surface of the coating is ensured.

6. The method for preparing the defect-free abrasion-resistant coating layer in an auxiliary manner by the synchronous ultrasonic shot blasting according to claim 1, wherein the high-speed cladding process adopts a coaxial powder feeding mode, the powder feeding gas is argon gas, and the cladding process is carried out under the argon gas protection environment.

7. The method of claim 1, wherein the motion behavior of the simultaneous ultrasonic peening assist system and the laser cladding system can be controlled independently.

8. The method of claim 1, wherein the cladding coating material is an abrasion resistant material with plastic deformation.

9. The method for preparing a defect-free abrasion-resistant coating by the aid of synchronous ultrasonic peening according to claim 1, wherein the synchronous ultrasonic peening system comprises an ultrasonic generator, a transducer, an amplitude rod, a peening chamber, a peening steel ball, a movement controller and a drive screw, the movement controller is connected with the drive screw, the movement controller can control the ultrasonic peening device to do linear reciprocating movement on the drive screw, the ultrasonic generator is connected to the transducer, the transducer is arranged on the upper end face of the movement controller, the peening chamber is arranged on the upper end of the amplitude rod, the lower end of the amplitude rod is connected with the transducer, and the peening steel ball is filled in the peening chamber.

Technical Field

The invention belongs to the technical field of preparation of wear-resistant and corrosion-resistant coatings on material surfaces, and particularly relates to a method for preparing a defect-free wear-resistant and corrosion-resistant coating by synchronous ultrasonic shot blasting.

Background

The laser cladding technology is a surface modification technology, which takes a high-energy laser beam as a heat source to simultaneously melt a cladding material and the surface of a metal matrix, and forms a metallurgical bonding interface coating with low dilution rate after rapid solidification, thereby obviously improving the physical properties of the surface of the matrix material, such as wear resistance, corrosion resistance, oxidation resistance and the like.

By utilizing the laser cladding technology, the required high-wear-resistance, corrosion-resistance or oxidation-resistance coating material can be prepared on the surface of the base material with low cost according to the actual service working condition requirement of the workpiece material, thereby obviously improving the service performance and the service life of the workpiece or the part. Therefore, the laser cladding surface modification technology has wide application prospect in the industries of mines, metallurgy, traffic, petroleum, electric power and the like.

In recent years, the ultra-high-speed laser cladding technology is rapidly developed, and compared with the traditional cladding technology, the cladding efficiency is remarkably improved (up to 2 m)²H) and ultra high speed laser claddingThe heat input to the matrix in the process is small, and the dilution rate of the coating and the thermal deformation of the base material are improved. However, in the high-speed cladding process, the coating is cracked inside due to the high solidification rate in the coating deposition process, and in addition, the conventional defect problems of cracks, air holes and the like at the interface of the coating and the base material still exist, so that the service performance and the service life of the prepared coating are seriously damaged. Therefore, how to solve the problem of defects generated at the coating and the interface thereof in the high-speed laser cladding process has important significance for promoting the industrial application of the high-speed laser cladding technology.

The solutions proposed in the prior art include: 1. ultrasonic vibration is directly introduced into a molten pool micro-area, and a stress field in a cladding layer is improved by virtue of the cavitation effect, the mechanical effect and the thermal effect of ultrasonic waves so as to inhibit the generation of cracks. 2. The vibration assistance is carried out on the cladding layer, so that the residual stress in the cladding layer can be reduced, and the effects of refining grains and homogenizing the structure are facilitated, thereby improving the structure and the performance of the cladding layer. 3. The ultrasonic impact auxiliary method is utilized to improve the tissue defect of the ultrahigh-speed laser cladding amorphous coating, and the aim of eliminating the solidification stress and the defect is fulfilled by adding an ultrasonic vibration head to a cladding area to generate a micro-forging effect. Although the above method has a beneficial effect on improving the structure and performance of the laser cladding coating, the ultrasonic vibration head is contacted with the surface of the cladding layer (the contact mode is nearly point contact), and the synchronous auxiliary strengthening effect is not ideal because the contact area is small, the cladding layer is difficult to be completely covered and the phenomenon of uneven strengthening effect in the cladding layer is easily caused.

Disclosure of Invention

In order to solve the problems, the invention provides a method for preparing a defect-free wear-resistant corrosion-resistant coating by synchronous ultrasonic shot blasting assisted high-speed laser cladding, which eliminates the defects of cracks, air holes and the like in the coating and on the interface of the coating by carrying out synchronous ultrasonic shot blasting strengthening treatment on a cladding layer in the high-speed cladding process, thins the grains of the coating, ensures the uniform ultrasonic shot blasting strengthening treatment effect on the surface of the cladding layer and realizes the high-efficiency preparation of the defect-free wear-resistant corrosion-resistant coating.

The specific technical scheme of the invention is implemented as follows:

a method for preparing a defect-free abrasion-resistant coating by synchronous ultrasonic shot blasting assistance specifically comprises the following specific steps:

s1: fixing a shaft sample to be processed on the integrated processing platform, and carrying out surface cleaning and rust removing treatment;

s2: baking and dehumidifying the powder to be clad, and filling the powder into a synchronous powder feeder;

s3: setting high-speed laser cladding parameters and setting the translation rate of a cladding head;

s4: adjusting a movement controller in the movement synchronous ultrasonic shot blasting system to enable a shot blasting cavity to be just positioned under a cladding head and to be positioned on the same horizontal plane with the cladding head, and setting the translation rate of the ultrasonic shot blasting auxiliary system to be the same as that of the cladding head in the cladding process and enabling the ultrasonic shot blasting auxiliary system to move in the same direction;

s5: and starting a high-speed laser cladding system, preparing a cladding coating on the surface of the sample, simultaneously starting an ultrasonic shot blasting auxiliary system, and carrying out synchronous ultrasonic shot blasting reinforcement treatment on the deposited coating until the cladding process is finished to obtain a defect-free abrasion-resistant coating.

Preferably, the surface cleaning and rust removing process in step S1 is to remove surface rust and stains by using sandpaper or a grinding wheel.

Preferably, the particle size range of the cladding powder in the step 2 is 10-200 μm, the baking and dehumidifying process needs to be carried out in a vacuum drying oven, the powder oxidation is avoided, the baking temperature is 120-150 ℃, and the baking time is 20-60 min.

Preferably, the process parameters of the high-speed laser cladding in the step 3 are as follows: the laser power is 0-6 KW, the distance between cladding and the surface of the sample is 10-16 mm, the cladding speed is 500-50000 mm/min, and the powder feeding speed is 0-5 r/min.

Preferably, the process parameters of the synchronous ultrasonic shot blasting in the step 3 are as follows: the frequency of the ultrasonic generator is 0-20 KHz, the diameter of the shot blasting steel ball is 1-5 mm, and the distance between the surface of the workpiece and the vibration head is 3-15 mm, so that the proper impact effect on the surface of the coating is ensured.

Preferably, the high-speed laser cladding adopts a coaxial powder feeding mode, the powder feeding gas is argon, and the cladding process is carried out under the argon protection environment.

Preferably, the motion behaviors of the synchronous ultrasonic shot blasting auxiliary system and the laser cladding system in the step 5 can be independently controlled.

Preferably, the coating material for high-speed laser cladding is an abrasion-resistant material with certain plastic deformation.

Preferably, synchronous ultrasonic peening system includes supersonic generator, transducer, amplitude pole, peening chamber, shot-blasting steel ball, motion control ware and drive screw are connected, the steerable supersound peening device of motion control ware is straight reciprocating motion on drive screw, supersonic generator is connected to the transducer, the transducer sets up at the motion control ware up end, the peening chamber sets up in amplitude pole upper end, amplitude pole lower extreme is connected with the transducer, the setting is filled at the peening intracavity to the shot-blasting steel ball.

Compared with the prior art, the invention has the beneficial effects that:

the ultrasonic shot blasting technology is utilized to synchronously strengthen the high-speed laser cladding layer, so that the defects of cracks, air holes and the like in the coating and at the interface are reduced, and the compactness and the interface bonding strength of the coating are enhanced; the grain refinement in the cladding layer can be induced by utilizing the ultrasonic shot blasting micro-forging effect to form a gradient structure from the surface to the inside, so that the surface hardness and the wear resistance of the coating are obviously improved; forming residual compressive stress on the surface of the coating through ultrasonic shot blasting treatment, and remarkably improving the fatigue resistance and service life of the coating; compared with the common ultrasonic vibration treatment, the ultrasonic shot blasting technology used in the invention has higher surface treatment efficiency, avoids the non-uniform phenomenon caused by smaller treatment area of the ultrasonic vibration head, and is beneficial to more uniform coating texture and high surface finish. The high-speed laser cladding abrasion-resistant coating prepared by the invention has no obvious macro-micro defects in the interior and at the interface, the crystal grains of the coating are obviously refined, the hardness is improved, and the abrasion resistance and the service life of the coating are obviously improved.

Drawings

FIG. 1 is a schematic view of an apparatus for preparing a defect-free abrasion-resistant coating by high-speed laser cladding with the assistance of synchronous ultrasonic shot blasting.

FIG. 2 is a schematic partial sectional view of a device B for preparing a defect-free abrasion-resistant coating by high-speed laser cladding with the assistance of synchronous ultrasonic shot blasting.

FIG. 3 is a metallographic photograph of a coating prepared by ordinary high-speed laser cladding and synchronous ultrasonic shot blasting assisted high-speed laser cladding.

FIG. 4 is an EBSD photo of the nano-crystal on the surface of the coating prepared by the synchronous ultrasonic shot-blasting assisted high-speed laser cladding.

FIG. 5 is a statistical table of characterization results of grain sizes.

The reference numerals are explained below:

1-laser, 2-synchronous powder feeder, 3-cladding head, 4-integrated processing platform, 5-ultrasonic generator, 6-transducer, 7-driving screw, 8-shot blasting cavity, 9-processing shaft sample, 10-mobile controller, 11-shot blasting steel ball and 12-amplitude rod.

Detailed Description

The present invention will be further described with reference to the following embodiments. Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

To further clarify the objects, features and functions of the present invention, a review board will be provided by referring to the following description of the preferred embodiments in conjunction with the accompanying drawings:

referring to fig. 1-5, the present invention is a method for preparing a defect-free abrasion-resistant coating by simultaneous ultrasonic shot blasting, which specifically comprises the following steps:

s1: fixing a shaft sample 9 to be processed on the integrated processing platform 4, and performing surface cleaning and rust removing treatment;

s2: baking and dehumidifying the powder to be clad, and filling the powder into a synchronous powder feeder 2;

s3: setting high-speed laser cladding parameters and setting the translation rate of a cladding head 3;

s4: adjusting a moving controller 10 in the moving synchronous ultrasonic shot blasting system to enable a shot blasting cavity 8 to be just positioned under the cladding head 3 and to be positioned on the same horizontal plane with the cladding head 3, and setting the translation rate of the ultrasonic shot blasting auxiliary system to be the same as that of the cladding head 3 in the cladding process and moving in the same direction;

s5: and starting a high-speed laser cladding system, preparing a cladding coating on the surface of the sample, simultaneously starting an ultrasonic shot blasting auxiliary system, and carrying out synchronous ultrasonic shot blasting reinforcement treatment on the deposited coating until the cladding process is finished to obtain a defect-free abrasion-resistant coating.

Preferably, the surface cleaning and rust removing process in step S1 is to remove surface rust and stains by using sandpaper or a grinding wheel.

Preferably, the particle size range of the cladding powder in the step 2 is 10-200 μm, the baking and dehumidifying process needs to be carried out in a vacuum drying oven, the powder oxidation is avoided, the baking temperature is 120-150 ℃, and the baking time is 20-60 min.

Preferably, the process parameters of the high-speed laser cladding in the step 3 are as follows: the laser power is 0-6 KW, the distance between cladding and the surface of the sample is 10-16 mm, the cladding speed is 500-50000 mm/min, and the powder feeding speed is 0-5 r/min.

Preferably, the process parameters of the synchronous ultrasonic shot blasting in the step 3 are as follows: the frequency of the ultrasonic generator is 0-20 KHz, the diameter of the shot blasting steel ball 11 is 1-5 mm, and the distance between the surface of the workpiece and the vibration head is 3-15 mm.

Preferably, the high-speed laser cladding adopts a coaxial powder feeding mode, the powder feeding gas is argon, and the cladding process is carried out under the argon protection environment.

Preferably, the motion behaviors of the synchronous ultrasonic shot blasting auxiliary system and the laser cladding system in the step 5 can be independently controlled.

Preferably, the coating material for high-speed laser cladding is an abrasion-resistant material with certain plastic deformation.

Preferably, synchronous ultrasonic peening system includes supersonic generator 5, transducer 6, drive screw 7, peening chamber 8, mobile controller 10, peening steel ball 11 and amplitude pole 12, mobile controller 5 is connected with drive screw 7, by drive screw 7 control mobile controller 10 do reciprocating motion, supersonic generator 5 is connected to transducer 6, transducer 6 sets up at mobile controller 10 up end, peening chamber 8 sets up at amplitude pole 12 upper end, amplitude pole 12 lower extreme is connected with transducer 6, peening steel ball 11 fills and sets up in peening chamber 8.

In this embodiment, the transducer 6 is mainly made of piezoelectric ceramics, converts the electric power input by the ultrasonic generator 5 into mechanical power, and transmits the mechanical power to the shot-blasting steel ball 11 through the amplitude rod 12. .

Example 1:

as shown in FIGS. 1-2, the method for preparing a defect-free abrasion-resistant coating layer by the aid of synchronous ultrasonic shot blasting specifically comprises the following steps:

firstly, a 45# steel base material shaft is taken as a processing shaft sample 9, a laser cladding wear-resistant coating is prepared on the surface of the processing shaft sample 9, the 45# steel base material shaft sample is installed on an integrated processing platform 4, surface cleaning and rust removing treatment is carried out, and rusts and stains on the surface of the processing shaft sample 9 are removed by using sand paper or a grinding wheel;

placing the Stellite6 alloy powder with the particle size range of 40-150 mu m as cladding powder into a vacuum drying oven for baking for 30min at the baking temperature of 120 ℃ to avoid powder oxidation, and then pouring the powder into a synchronous powder feeder 2;

adjusting the power of a laser 1 to be 2KW, setting the distance from a cladding head 3 to the surface of the sample to be 12mm, setting the cladding lap joint rate to be 60 percent, and setting the linear speed of laser cladding to be 4000 mm/min;

the position of a moving controller 10 in the synchronous ultrasonic shot blasting system is adjusted through a transmission screw 7, so that a shot blasting cavity 8 is just positioned below a cladding head 3, the translation speed of the moving controller 10 on a transverse moving base is set to be in the same direction and consistent with that of the cladding head 3, and a transducer 6, the shot blasting cavity 8, an amplitude rod 12 and the cladding head 3 which are arranged on the moving controller 10 are enabled to keep synchronous operation;

the frequency of the ultrasonic generator 5 is set to be 20KHz, the distance between the amplitude rod 12 and the surface of the sample is 10mm, and the diameter of the shot blasting steel ball 11 is 3 mm.

Starting the synchronous powder feeder 2, taking argon as powder feeding gas and protective gas, adjusting the powder feeding speed to be 0.6r/min, the powder feeding gas flow to be 2.5L/min and the protective gas flow to be 16L/min, and feeding cladding powder to a cladding head 3; when the powder output in the cladding head 3 is stable, the integrated processing platform 4 and the laser 1 are started to prepare a cladding coating, the mobile controller 10 and the ultrasonic generator 5 are started simultaneously, the ultrasonic generator 5 is connected to the transducer 6, the electric power input by the ultrasonic generator 5 is converted into mechanical power by the transducer 6, the mechanical power is transmitted to a shot blasting steel ball 11 in a shot blasting cavity 8 through an amplitude rod, the defects in the coating and at the interface are eliminated by means of the ultrasonic impact effect of the shot blasting steel ball on the surface of the cladding coating, and the service performance of the coating is improved.

And after the cladding coating is processed, closing the laser 1, the powder feeder 2, the ultrasonic generator 5, the integrated processing platform 4 and the mobile controller 10 in sequence, so that the defect-free Stellite6 wear-resistant coating can be prepared on the surface of the 45 steel substrate, and the surface modification treatment of the substrate material is completed.

Referring to fig. 3, due to the fast cooling rate during the high-speed laser cladding process, there are significant crack defects inside the coating that is not treated by ultrasonic peening (left panel); after the synchronous ultrasonic shot blasting treatment is applied, the cracking phenomenon in the coating is eliminated, and the interface bonding is excellent (right graph);

as shown in fig. 4-5, the grain structure of the laser cladding coating is obviously refined under the assistance of the synchronous ultrasonic shot blasting, and obvious surface nanocrystals appear on the surface layer of the coating, and the appearance of the surface nanocrystals is proved by the characterization result table of the grain size in fig. 5, and the hardness of the surface of the cladding coating without defects can reach 600HV, which is obviously higher than 430HV of the coating without shot blasting through the hardness test; the oxidation weight gain of the Stellite6 coating after the synchronous ultrasonic shot blasting treatment at the high temperature of 700 ℃ for 50h is 12.7g/m2, and is reduced by about 75.3 percent compared with that of an untreated coating.

Example 2:

the invention relates to a method for preparing a defect-free wear-resistant corrosion-resistant coating by synchronous ultrasonic shot blasting, which is implemented by the following steps:

firstly, preparing a laser cladding wear-resistant coating on the surface of a 16Mn shaft sample serving as a processing shaft sample 9, mounting the 16Mn shaft sample on an integrated processing platform 4, carrying out surface cleaning and rust removing treatment, and removing rust and stains on the surface of the processing shaft sample 9 by using sand paper or a grinding wheel;

putting 316L with the particle size range of 100-170 mu m as cladding powder into a vacuum drying oven for baking at 150 ℃ for 30min to avoid powder oxidation, and then pouring the powder into a synchronous powder feeder 2;

adjusting the power of a laser 1 to be 1-3 KW, setting the distance between a cladding head 3 and the surface of a sample to be 12mm, setting the cladding lap joint rate to be 50%, and setting the linear speed of laser cladding to be 4000 mm/min;

the position of a moving controller 10 in the synchronous ultrasonic shot blasting system is adjusted through a transmission screw 7, so that a shot blasting cavity 8 is just positioned below a cladding head 3, the translation speed of the moving controller 10 on a transverse moving base is set to be in the same direction and consistent with that of the cladding head 3, and a transducer 6, the shot blasting cavity 8, an amplitude rod 12 and the cladding head 3 which are arranged on the moving controller 10 are enabled to keep synchronous operation;

the frequency of the ultrasonic generator 5 is set to be 20KHz, the distance between the amplitude rod 12 and the surface of the sample is 8mm, and the diameter of the shot blasting steel ball 11 is 4 mm.

Starting the synchronous powder feeder 2, taking argon as powder feeding gas and protective gas, adjusting the powder feeding speed to be 0.5r/min, the powder feeding gas flow to be 2.7L/min and the protective gas flow to be 15L/min, and feeding cladding powder to a cladding head 3; when the powder output in the cladding head 3 is stable, the integrated processing platform 4 and the laser 1 are started to prepare a cladding coating, the mobile controller 10 and the ultrasonic generator 5 are started simultaneously, the ultrasonic generator 5 is connected to the transducer 6, the electric power input by the ultrasonic generator 5 is converted into mechanical power by the transducer 6, the mechanical power is transmitted to a shot blasting steel ball 11 in a shot blasting cavity 8 through an amplitude rod, the defects in the coating and at the interface are eliminated by means of the ultrasonic impact effect of the shot blasting steel ball on the surface of the cladding coating, and the service performance of the coating is improved.

And after the cladding coating is processed, closing the laser 1, the powder feeder 2, the ultrasonic generator 5, the integrated processing platform 4 and the mobile controller 10 in sequence, thus obtaining a defect-free 316L wear-resistant corrosion-resistant coating on the 16Mn shaft sample and finishing the surface modification treatment on the substrate material.

Compared with the conventional cladding method, the 316L laser cladding coating prepared by the synchronous ultrasonic shot blasting auxiliary method has no air holes and crack defects in the interior and at the interface with the substrate; the surface of the coating after the synchronous ultrasonic shot blasting treatment has a nanocrystalline structure, the surface hardness of the coating is increased from 206HV to 391HV, and the corrosion rate (0.01mm/a) of the coating in a simulated oil field produced fluid is reduced by about 68%.

Example 3:

the invention relates to a method for preparing a defect-free wear-resistant corrosion-resistant coating by synchronous ultrasonic shot blasting, which is implemented by the following steps:

firstly, a 45# steel base material shaft is taken as a processing shaft sample 9, a laser cladding wear-resistant coating is prepared on the surface of the processing shaft sample 9, the 45# steel base material shaft sample is installed on an integrated processing platform 4, surface cleaning and rust removing treatment is carried out, and rusts and stains on the surface of the processing shaft sample 9 are removed by using sand paper or a grinding wheel;

placing Ni60 alloy powder with the particle size of 10-60 mu m as cladding powder into a vacuum drying oven for baking at 150 ℃ for 40min to avoid powder oxidation, and then pouring the powder into a synchronous powder feeder 2;

adjusting the power of a laser 1 to be 4KW, setting the distance from a cladding head 3 to the surface of the sample to be 14mm, setting the cladding lap-joint rate to be 70%, and setting the linear speed of laser cladding to be 20000 mm/min;

the position of a moving controller 10 in the synchronous ultrasonic shot blasting system is adjusted through a transmission screw 7, so that a shot blasting cavity 8 is just positioned below a cladding head 3, the translation speed of the moving controller 10 on a transverse moving base is set to be in the same direction and consistent with that of the cladding head 3, and a transducer 6, the shot blasting cavity 8, an amplitude rod 12 and the cladding head 3 which are arranged on the moving controller 10 are enabled to keep synchronous operation;

the frequency of the ultrasonic generator 5 is set to be 20KHz, the distance between the amplitude rod 12 and the surface of the sample is 5mm, and the diameter of the shot blasting steel ball 11 is 2 mm.

Starting the synchronous powder feeder 2, taking argon as powder feeding gas and protective gas, adjusting the powder feeding speed to be 0.8r/min, the powder feeding gas flow to be 2.7L/min and the protective gas flow to be 18L/min, and feeding cladding powder to a cladding head 3; when the powder output in the cladding head 3 is stable, the integrated processing platform 4 and the laser 1 are started to prepare a cladding coating, the mobile controller 10 and the ultrasonic generator 5 are started simultaneously, the ultrasonic generator 5 is connected to the transducer 6, the electric power input by the ultrasonic generator 5 is converted into mechanical power by the transducer 6, the mechanical power is transmitted to a shot blasting steel ball 11 in a shot blasting cavity 8 through an amplitude rod, the defects in the coating and at the interface are eliminated by means of the ultrasonic impact effect of the shot blasting steel ball on the surface of the cladding coating, and the service performance of the coating is improved.

And after the cladding coating is processed, closing the laser 1, the powder feeder 2, the ultrasonic generator 5, the integrated processing platform 4 and the mobile controller 10 in sequence, so that the defect-free Ni60 wear-resistant corrosion-resistant coating can be prepared on the surface of the 45# steel base material shaft, and the surface modification treatment of the base material is completed.

By representing the microstructure and the performance of the high-speed laser cladding coating, the fact that the coating without the assistance of ultrasonic shot blasting has more internal cracks and obvious cracking phenomenon at the interface of the coating and a substrate is found, the coating with the assistance of synchronous ultrasonic shot blasting has no obvious defects at the internal part and the interface, and the grain structure of the coating is obviously refined; the surface hardness of the Ni60 coating subjected to the synchronous ultrasonic shot blasting auxiliary treatment is 65.3HRC, which is improved by about 12.8 percent compared with that of the coating without auxiliary strengthening (57.9 HRC); the abrasion weight loss of the Ni60 coating prepared by the method is about 1.35mg at 700 ℃, and is reduced by about 27.6% compared with the coating which is not subjected to ultrasonic shot blasting auxiliary treatment.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.