阅读说明：本技术 脉冲电流辅助超声滚压表面强化装置及方法 (Pulse current assisted ultrasonic rolling surface strengthening device and method ) 是由 屈盛官 任朝军 贾思钰 胡雄风 李小强 于 2020-12-11 设计创作，主要内容包括：本发明公开了一种脉冲电流辅助超声滚压表面强化装置及方法,所述装置包括脉冲电源、导电零件、夹紧机构和超声滚压模块,所述夹紧机构用于夹紧工件,且夹紧机构由车床带动转动,所述导电零件与夹紧机构接触,所述脉冲电源与导电零件连接,用于将脉冲电流施加到工件上,所述超声滚压模块用于对工件表面进行脉冲电流辅助超声滚压表面强化处理。本发明将脉冲电流的电致塑效应、集肤效应和热效应与超声滚压引起的剧烈塑性变形进行复合,使强化表层更厚、表层性能更好,可以提高金属材料的表面强化效果,使得金属材料的表面形貌更好,从而提高金属材料的性能。(The invention discloses a pulse current auxiliary ultrasonic rolling surface strengthening device and a pulse current auxiliary ultrasonic rolling surface strengthening method. The invention compounds the electro-plastic effect, the skin effect and the thermal effect of the pulse current with the violent plastic deformation caused by the ultrasonic rolling, so that the reinforced surface layer is thicker and the surface layer performance is better, the surface reinforcing effect of the metal material can be improved, the surface appearance of the metal material is better, and the performance of the metal material is improved.)

1. The pulse current assisted ultrasonic rolling surface strengthening device is characterized by comprising a pulse power supply, a conductive part, a clamping mechanism and an ultrasonic rolling module, wherein the clamping mechanism is used for clamping a workpiece and driven by a lathe to rotate, the conductive part is in contact with the clamping mechanism, the pulse power supply is connected with the conductive part and used for applying pulse current to the workpiece, and the ultrasonic rolling module is used for conducting pulse current assisted ultrasonic rolling surface strengthening treatment on the surface of the workpiece.

2. The device for reinforcing the ultrasonic rolling surface by the aid of the pulse current as claimed in claim 1, wherein the clamping mechanism comprises a first chuck, a second chuck and a third chuck, the second chuck is a cylindrical shank chuck, the third chuck is a conical shank chuck, the first chuck is connected with a lathe spindle, the second chuck is mounted on the first chuck, the third chuck is mounted in a conical shank hole on a lathe tailstock, the center lines of the second chuck and the third chuck are on the same horizontal line, and the second chuck and the third chuck are oppositely arranged and used for clamping a workpiece.

3. The pulsed current assisted ultrasonic roll surface enhancement device of claim 2 wherein the conductive elements comprise a first conductive member and a second conductive member, the first conductive member contacting the second chuck and connected by a first wire to the first output of the pulsed power supply, the second conductive member contacting the third chuck and connected by a second wire to the second output of the pulsed power supply.

4. The pulsed current assisted ultrasonic rolled surface enhancing device according to claim 2, wherein a first insulating member is arranged between the first chuck and the second chuck, and a second insulating member is sleeved on the conical handle of the third chuck.

5. The pulsed current assisted ultrasonic rolling surface strengthening device of any one of claims 1 to 4, wherein the ultrasonic rolling module comprises an ultrasonic rolling tool, an ultrasonic control cabinet and an air compressor, the ultrasonic rolling tool is mounted on a lathe tool rest and is respectively connected with the ultrasonic control cabinet and the air compressor.

6. The pulsed current assisted ultrasonic rolling surface strengthening device as claimed in claim 5, wherein the ultrasonic rolling tool comprises a tool body, a cylinder, an ultrasonic transducer, an amplitude transformer, a tool bit and a rolling ball, a compressed air hole of the cylinder is connected with an air compressor through an air pipe, the cylinder is connected with the ultrasonic transducer, a control cable hole of the ultrasonic transducer is connected with an ultrasonic control cabinet through a cable, the ultrasonic transducer is connected with the amplitude transformer, a lubricating oil hole of the amplitude transformer is connected with a lubricating oil output pipe of the ultrasonic control cabinet through an oil pipe, the tool bit is fixed on the tool body, the rolling ball is mounted on the tool bit and pushed by the amplitude transformer, and the rolling ball and the central line of the workpiece are located on the same horizontal plane.

7. The pulsed current assisted ultrasonic rolled surface enhancing apparatus of claim 5, wherein the ultrasonic rolling tool is provided with a third insulating member.

8. The pulsed current assisted ultrasonic rolled surface enhancing device of claim 5, wherein the rolled spheres are ceramic material.

9. The device for ultrasonic rolling surface strengthening assisted by pulse current according to any one of claims 1 to 4 and 6 to 8, wherein the pulse power supply is a direct current pulse argon arc welding machine, an alternating current pulse argon arc welding machine, a direct current welding machine or an alternating current welding machine.

10. A method for strengthening a surface by ultrasonic rolling assisted by pulse current, which is realized based on the device of any one of claims 1 to 9, and is characterized in that the method comprises the following steps:

clamping the workpiece through a clamping mechanism;

starting the lathe, driving the clamping mechanism to rotate the workpiece through the lathe spindle, and selecting a proper rotating speed of the lathe spindle;

starting a pulse power supply to apply pulse current to a workpiece, primarily selecting the pulse current, the pulse frequency and the pulse width output by the pulse power supply, and utilizing the electro-plastic effect, the skin effect and the thermal effect of the pulse current to enable the workpiece to reach a state more suitable for ultrasonic rolling surface strengthening treatment;

starting an ultrasonic control cabinet of the ultrasonic rolling module, and setting proper ultrasonic frequency, amplitude and lubricating oil quantity; setting a proper air pressure;

and under the condition of keeping the pulse current, enabling an ultrasonic rolling cutter of the ultrasonic rolling module to move along the axial direction of the workpiece, and carrying out pulse current auxiliary ultrasonic rolling surface strengthening treatment on the surface of the workpiece.

11. The method for strengthening the ultrasonic rolling surface by pulse current assistance according to claim 10, wherein the method further comprises the following step of moving the ultrasonic rolling tool of the ultrasonic rolling module along the axial direction of the workpiece while maintaining the pulse current, and after the pulse current assistance ultrasonic rolling surface strengthening treatment is performed on the surface of the workpiece:

and adjusting the pulse current, the pulse frequency and the pulse width, keeping for a certain time, and then enabling the ultrasonic rolling cutter to move along the axial direction of the workpiece to carry out pulse current-assisted ultrasonic rolling surface strengthening treatment on the surface of the workpiece.

12. The method for reinforcing the ultrasonic rolling surface under the assistance of the pulse current according to any one of claims 10 to 11, wherein the range of the pulse current output by the pulse power supply is 30A to 400A, the range of the pulse frequency is 100Hz to 5000Hz, and the range of the pulse width is 50 μm to 250 μm; the temperature range for heating the workpiece is 25-400 ℃.

13. The method for ultrasonic rolling surface strengthening assisted by pulse current according to any one of claims 10 to 11, wherein the rotating speed of the lathe spindle is in a range of 10r/min to 80 r/min.

14. The method for strengthening the ultrasonic rolling surface by the aid of the pulse current according to any one of claims 10 to 11, wherein the ultrasonic frequency output by the ultrasonic control cabinet is in a range of 10 to 40kHz, and the amplitude of the ultrasonic wave output by the ultrasonic control cabinet is in a range of 1 to 14 μm.

15. The method for strengthening the surface of a workpiece by pulsed current assisted ultrasonic rolling according to any one of claims 10 to 11, wherein the number of times of the pulsed current assisted ultrasonic rolling surface strengthening treatment on the surface of the workpiece is 1 to 40.

Technical Field

The invention relates to a pulse current assisted ultrasonic rolling surface strengthening device and method, and belongs to the technical field of metal material surface treatment.

Background

With the development of the industries such as aerospace, heavy equipment, transportation, chemical equipment, light industrial instruments, medical instruments, ship industry, marine equipment and the like, many mechanical equipment works under severe working conditions, and parts are required to have good comprehensive properties such as wear resistance, corrosion resistance, fatigue resistance and the like, so that the equipment can run safely and reliably.

The ultrasonic rolling surface strengthening technology is a surface modification and surface strengthening technology, wherein an ultrasonic rolling cutter extrudes the surface of a workpiece at a certain pressure, and simultaneously impacts the surface of the workpiece at a certain frequency, so that the surface layer of the workpiece generates severe plastic deformation, and crystal grains on the surface layer are refined. The ultrasonic rolling can reduce the surface roughness, improve the surface appearance, reduce the defects, eliminate tool marks and the like, improve the hardness of the surface layer of the workpiece, and generate residual compression pressure in the surface layer, so that the material is more wear-resistant, more corrosion-resistant and more fatigue-resistant. The method plays an important role in improving the surface performance of the material, and is widely applied to surface strengthening of the material. However, for some materials with higher hardness or difficult processing, the surface layer has high hardness and low plasticity, the ultrasonic rolling is difficult to generate sufficient plastic deformation on the surface layer, a better strengthened surface layer is also difficult to obtain, and the performance of the surface layer is very difficult to improve by simply adjusting the technological parameters of the ultrasonic rolling. In addition, when ultrasonic rolling is performed, a hardened surface layer generated by previous ultrasonic rolling can be an obstacle to plastic deformation when ultrasonic rolling is performed next time, so that the subsequent ultrasonic rolling effect cannot reach deeper parts of the material.

Therefore, it is necessary to improve the existing ultrasonic rolling technology to make the ultrasonic rolling effect reach deeper into the material, so as to form a thicker material surface layer with better comprehensive performance.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provides the pulse current auxiliary ultrasonic rolling surface strengthening device, which combines the electro-plastic effect, the skin effect and the thermal effect of pulse current with severe plastic deformation caused by ultrasonic rolling, so that the strengthened surface layer is thicker and the surface layer performance is better, the surface strengthening effect of the metal material is improved, and the surface appearance and the performance of the metal material are better.

The invention also aims to provide a pulse current auxiliary ultrasonic rolling surface strengthening method.

The purpose of the invention can be achieved by adopting the following technical scheme:

the utility model provides a supplementary supersound roll extrusion surface strengthening device of pulse current, includes pulse power supply, conductive part, clamping mechanism and supersound roll extrusion module, clamping mechanism is used for pressing from both sides tight work piece, and clamping mechanism is driven by the lathe and rotates, conductive part and clamping mechanism contact, pulse power supply is connected with conductive part for exert pulse current on the work piece, supersound roll extrusion module is used for carrying out the supplementary supersound roll extrusion surface strengthening treatment of pulse current to the work piece surface.

Further, clamping mechanism includes first chuck, second chuck and third chuck, the second chuck is the cylinder handle chuck, the third chuck is the circular cone handle chuck, first chuck is connected with the lathe spindle, the second chuck is installed on first chuck, the third chuck is installed in the taper shank hole on the lathe tailstock, the central line of second chuck and third chuck is on same water flat line, and sets up relatively between second chuck and the third chuck for press from both sides tight work piece.

Further, the conductive part includes a first conductive piece and a second conductive piece, the first conductive piece contacts with the second chuck, and the first conductive piece is connected with the first output end of the pulse power supply through a first wire, the second conductive piece contacts with the third chuck, and the second conductive piece is connected with the second output end of the pulse power supply through a second wire.

Furthermore, a first insulating part is arranged between the first chuck and the second chuck, and a second insulating part is sleeved on the conical handle of the third chuck.

Furthermore, the ultrasonic rolling module comprises an ultrasonic rolling tool, an ultrasonic control cabinet and an air compressor, wherein the ultrasonic rolling tool is mounted on the lathe tool rest and is respectively connected with the ultrasonic control cabinet and the air compressor.

Furthermore, the ultrasonic rolling tool comprises a tool body, an air cylinder, an ultrasonic transducer, an amplitude transformer, a tool bit and a rolling ball body, wherein a compressed air hole of the air cylinder is connected with an air compressor through an air pipe, the air cylinder is connected with the ultrasonic transducer, a control cable hole of the ultrasonic transducer is connected with an ultrasonic control cabinet through a cable, the ultrasonic transducer is connected with the amplitude transformer, a lubricating oil hole of the amplitude transformer is connected with a lubricating oil output pipe of the ultrasonic control cabinet through an oil pipe, the tool bit is fixed on the tool body, the rolling ball body is installed on the tool bit and is pushed by the amplitude transformer, and the rolling ball body and the central line of the workpiece are located on the same horizontal plane.

Furthermore, a third insulating part is arranged on the ultrasonic rolling cutter.

Further, the rolling ball body is made of ceramic materials.

Furthermore, the pulse power supply is a direct current pulse argon arc welding machine, an alternating current pulse argon arc welding machine, a direct current welding machine or an alternating current welding machine.

The other purpose of the invention can be achieved by adopting the following technical scheme:

a pulse current assisted ultrasonic rolling surface strengthening method is realized based on the device, and the method comprises the following steps:

clamping the workpiece through a clamping mechanism;

starting the lathe, driving the clamping mechanism to rotate the workpiece through the lathe spindle, and selecting a proper rotating speed of the lathe spindle;

starting a pulse power supply to apply pulse current to a workpiece, primarily selecting the pulse current, the pulse frequency and the pulse width output by the pulse power supply, and utilizing the electro-plastic effect, the skin effect and the thermal effect of the pulse current to enable the workpiece to reach a state more suitable for ultrasonic rolling surface strengthening treatment;

and starting an ultrasonic control cabinet of the ultrasonic rolling module, and setting proper ultrasonic frequency, amplitude and lubricating oil quantity. An appropriate air pressure is set.

And under the condition of keeping the pulse current, enabling an ultrasonic rolling cutter of the ultrasonic rolling module to move along the axial direction of the workpiece, and carrying out pulse current auxiliary ultrasonic rolling surface strengthening treatment on the surface of the workpiece.

Further, under the condition of keeping the pulse current, after the ultrasonic rolling tool of the ultrasonic rolling module moves along the axial direction of the workpiece and performs the pulse current assisted ultrasonic rolling surface strengthening treatment on the surface of the workpiece, the method further comprises the following steps:

and adjusting the pulse current, the pulse frequency and the pulse width, keeping for a certain time, and then enabling the ultrasonic rolling cutter to move along the axial direction of the workpiece to carry out pulse current-assisted ultrasonic rolling surface strengthening treatment on the surface of the workpiece.

Further, the range of the pulse current output by the pulse power supply is 30-400A, the range of the pulse frequency is 100-5000 Hz, and the range of the pulse width is 50-250 μm; the temperature range for heating the workpiece is 25-400 ℃.

Further, the rotating speed range of the lathe spindle is 10 r/min-80 r/min.

Furthermore, the range of the ultrasonic frequency output by the ultrasonic control cabinet is 10-40 kHz, and the range of the amplitude is 1-14 μm.

Furthermore, the frequency of pulse current auxiliary ultrasonic rolling on the surface of the workpiece is 1-40 times.

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

1. according to the invention, the pulse power supply is connected with the conductive part, the pulse current is applied to the workpiece to be processed clamped by the clamping mechanism, and the plastic deformation resistance of the surface layer of the metal material is reduced by utilizing the electro-plastic effect, the skin effect and the thermal effect of the pulse current, so that the surface layer of the material is in a good plastic state, and the reinforcing effect of ultrasonic rolling can reach a deeper position of the material. The method can also overcome the obstruction of a hardened layer formed by the last ultrasonic rolling to the subsequent ultrasonic rolling strengthening effect in the multiple ultrasonic rolling process, enhance the ultrasonic rolling strengthening effect, make the strengthened layer thicker, refine the crystal grains on the surface layer of the material and even generate a nano layer, improve the wear resistance, corrosion resistance and fatigue resistance of the surface layer of the material, have more excellent comprehensive performance, and have the strengthening effect superior to the single ultrasonic rolling strengthening effect.

2. The invention is suitable for surface strengthening treatment of some metal materials with high hardness and poor plasticity and metal materials with serious work hardening, and can generate thicker strengthening layers on the surface layers. The method can also overcome and weaken the barrier effect of the last strengthening layer on the next strengthening, and obtain a strengthening surface layer with better performance, and is suitable for the condition of less strengthening times and the condition of more strengthening times.

3. The method is simple and easy to implement, is suitable for surface strengthening of shaft and rod parts, and is suitable for surface strengthening treatment of various metal materials. The device has simple structure, and has low cost and good effect compared with a special pulse power supply for surface strengthening.

4. By setting the pulse current, the pulse frequency, the pulse width, the workpiece heating temperature, the rotating speed of a lathe spindle, the ultrasonic frequency and the amplitude of an ultrasonic control cabinet and the frequency of pulse current-assisted ultrasonic rolling treatment on the surface of the workpiece, the surface roughness of the material can be reduced and the surface appearance can be improved after the surface strengthening treatment of the pulse current-assisted ultrasonic rolling treatment, so that the mirror surface effect is achieved; the surface hardness of the material can be improved, the hardness of the material is increased by more than 25 percent compared with that of the untreated material, and the residual compression stress of about 1000MPa is formed in the surface layer. The surface strengthening layer is thicker, so that the performance of the surface layer of the material is improved, the surface of the material is more wear-resistant, corrosion-resistant and fatigue-resistant, and the comprehensive performance of the material is better than that of a single ultrasonic rolling strengthening effect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is to be understood that the drawings in the following description are merely exemplary of the invention and that other drawings may be derived from the structure shown in the drawings by those skilled in the art without the exercise of inventive faculty.

Fig. 1 is a schematic structural diagram of a pulsed current assisted ultrasonic rolling surface strengthening device in embodiment 1 of the present invention.

Fig. 2 is a schematic structural view of a clamping mechanism clamping a workpiece according to embodiment 1 of the present invention.

Fig. 3 is a structural block diagram of an ultrasonic rolling module according to embodiment 1 of the present invention.

Fig. 4 is a schematic structural view of an ultrasonic rolling tool in embodiment 1 of the present invention.

Fig. 5 is a flowchart of a method for reinforcing a surface by ultrasonic rolling with the assistance of pulse current in embodiment 1 of the present invention.

The ultrasonic vibration testing device comprises a pulse power supply 1, a clamping mechanism 2, a first chuck 201, a second chuck 202, a third chuck 203, a first insulating part 204, a second insulating part 205, a lathe tailstock 3, a workpiece 4, a first conducting part 5, a second conducting part 6, a first conducting wire 7, a second conducting wire 8, an ultrasonic rolling cutter 9, an air cylinder 901, an ultrasonic transducer 902, an amplitude transformer 903, a cutter head 904, a rolling sphere 905, an ultrasonic control cabinet 10, an air compressor 11 and a third insulating part 12.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, not all embodiments, and all other embodiments obtained by those skilled in the art without inventive work are within the scope of the present invention.

Example 1:

as shown in fig. 1, the present embodiment provides a pulsed current assisted ultrasonic rolling surface strengthening device, which is implemented on a lathe and includes a pulsed power supply 1, a conductive part, a clamping mechanism 2 and an ultrasonic rolling module, wherein only a lathe tailstock 3 of the lathe is shown in the figure, and other parts of the lathe are not shown.

The clamping mechanism 2 is used for clamping a workpiece 4, and the clamping mechanism 2 is driven by a lathe to rotate, wherein the workpiece 4 is made of a metal material, as shown in fig. 1 and fig. 2, the clamping mechanism 2 comprises a first chuck 201, a second chuck 202 and a third chuck 203, the second chuck 202 is a cylindrical shank chuck, the third chuck 203 is a conical shank chuck, the first chuck 201 can be a chuck which the lathe itself has, the first chuck 201 is connected with a spindle of the lathe, the second chuck 202 is mounted on the first chuck 201, the third chuck 203 is mounted in a conical shank hole on a tailstock 3 of the lathe, center lines of the second chuck 202 and the third chuck 203 are on the same horizontal line, and the second chuck 202 and the third chuck 203 are oppositely arranged and used for clamping the workpiece 4; after the lathe is started, the first chuck 201 is driven to rotate by the lathe spindle, and the second chuck 202 is driven to rotate by the first chuck 201, so that the third chuck 203 and the workpiece 4 are driven to rotate. When the clamping mechanism 2 works, the first insulating part 204 is sleeved on the second chuck 202, and then the second chuck 202 sleeved with the first insulating part 204 is installed on the first chuck 201, so that the first chuck 201 is clamped; sleeving the second insulating part 205 on the taper shank of the third chuck 203, and then installing the third chuck 203 sleeved with the second insulating part 205 in the taper shank hole on the lathe tailstock 3 to ensure that the third chuck is firmly installed; adjusting the position of the lathe tailstock 3 on a lathe guide rail, and adjusting the distance between the second chuck 202 and the third chuck 203; mounting the workpiece 4 on the second chuck 202 and the third chuck 203, and causing the jaws of the second chuck 202 and the third chuck 203 to grip the workpiece 4; the lathe tailstock 3 is fixed on a lathe guide rail.

The conductive part is contacted with the clamping mechanism 2, and the pulse power supply 1 is connected with the conductive part and is used for applying pulse current to the workpiece 4; specifically, the conductive part includes a first conductive member 5 and a second conductive member 6, the first conductive member 5 is in close contact with the second chuck 202, the first conductive member 5 is connected to the first output terminal of the pulse power supply 1 through a first wire 7, the second conductive member 6 is in close contact with the third chuck 203, and the second conductive member 6 is connected to the second output terminal of the pulse power supply 1 through a second wire 8, the second chuck 202, the first conductive member 5, the first wire 7, the pulse power supply 1, the second wire 8, the third chuck 203 and the workpiece 4 form a closed loop through which a pulse current passes, so that the pulse current can be applied to the workpiece 4, and the first conductive member 5 and the second conductive member 6 in this embodiment are both carbon brushes (also called brushes).

Further, the pulse power supply 1 is a direct-current pulse argon arc welding machine (only shown in the figure, specifically based on the product object), the pulse current (pulse argon arc welding) function of the direct-current pulse argon arc welding machine is selected, parameters such as pulse current, pulse frequency and pulse width can be set according to actual needs, and the workpiece 4 is processed by using the pulse current, so that the workpiece 4 can reach a state more suitable for ultrasonic rolling surface strengthening treatment.

The ultrasonic rolling module is used for performing pulse current-assisted ultrasonic rolling on the surface of the workpiece 4, and as shown in fig. 1 and 3, the ultrasonic rolling module comprises an ultrasonic rolling tool 9, an ultrasonic control cabinet 10 and an air compressor 11, the ultrasonic rolling tool 9 is clamped on a lathe tool rest and is respectively connected with the ultrasonic control cabinet 10 and the air compressor 11, and the ultrasonic frequency, the amplitude and the lubricating oil quantity can be set through the ultrasonic control cabinet 10. The gas pressure of the air compressor 11 may be set as necessary.

Further, as shown in fig. 1, 3 and 4, the ultrasonic rolling tool 9 includes a tool body, an air cylinder 901, an ultrasonic transducer 902, an amplitude transformer 903, a tool bit 904 and a rolling sphere 905, a compressed air hole 9011 of the air cylinder 901 is connected with an air compressor 11 through an air pipe, the air cylinder 901 is connected with the ultrasonic transducer 902, a control cable hole 9021 of the ultrasonic transducer 902 is connected with the ultrasonic control cabinet 10 through a cable, the ultrasonic transducer 902 is connected with the amplitude transformer 903 for driving the amplitude transformer 903, a lubricating oil hole 9031 of the amplitude transformer 903 is connected with a lubricating oil output pipe of the ultrasonic control cabinet 10 through an oil pipe for lubricating and cooling the rolling sphere 905, the tool bit 904 is fixed on the tool body, the rolling sphere 905 is installed on the tool bit 904, the rolling sphere 905 is pushed by the amplitude transformer 903, and the central lines of the rolling sphere 905 and the workpiece 4 are located on the same horizontal plane, the rolling sphere 905 of this embodiment is made of a ceramic, can be silicon nitride ceramic spheres or zirconia ceramic spheres.

When the ultrasonic rolling module works, a third insulating part 12 is arranged on an ultrasonic rolling cutter 9, the third insulating part 12 is used for insulating the ultrasonic rolling cutter 12 and a lathe tool rest, then the ultrasonic rolling cutter 9 provided with the third insulating part 12 is installed on the lathe tool rest, the center of a rolling sphere 905 is aligned, the rolling sphere 905 and the center line of a workpiece 4 are located on the same horizontal plane, the gas pressure of an air compressor 11, namely the gas pressure of an air cylinder 901 is set, the gas pressure of the air cylinder 901 reaches a proper value, a tool bit 904 is pressed against the surface of the workpiece 4, and the ultrasonic frequency, the amplitude, the flow rate of lubricating oil and the like are adjusted to proper values on an ultrasonic control cabinet 10; after the lathe is started to drive the workpiece 4 to rotate, the lathe tool rest drives the ultrasonic rolling tool 9 to axially move along the workpiece 4, and pulse current auxiliary ultrasonic rolling surface strengthening treatment is carried out on the surface of the workpiece 4.

In addition to the first insulating member 204, the first insulating member 204 and the third insulating member 12, an insulating plate or an insulating pad (not shown) may be disposed at the bottom of the left and right bed legs of the lathe, so that the left and right bed legs are insulated from the ground.

As shown in fig. 1 to 5, the present embodiment provides a method for enhancing a surface by ultrasonic rolling assisted by a pulse current, which is implemented based on the above apparatus, and includes the following steps:

and S1, clamping the workpiece through the clamping mechanism 2.

Specifically, the workpiece 4 is mounted on the second chuck 202 and the third chuck 203 of the clamping mechanism 2, and the jaws of the second chuck 202 and the third chuck 203 are caused to clamp the workpiece 4.

And S2, starting the lathe, driving the clamping mechanism 2 to rotate the workpiece 4 through the lathe spindle, and selecting the proper lathe spindle rotating speed.

Specifically, the first chuck 201 is driven to rotate by the lathe spindle, the second chuck 202 is driven to rotate by the first chuck 201, so that the third chuck 203 and the workpiece 4 are driven to rotate, a proper rotating speed of the lathe spindle is selected, the rotating speed of the lathe spindle is the rotating speed of the workpiece 4, and the rotating speed range of the lathe spindle is 10 r/min-80 r/min.

S3, starting the pulse power supply 1 to apply pulse current to the workpiece 4, primarily selecting the pulse current, the pulse frequency and the pulse width output by the pulse power supply 1, and utilizing the electro-plastic effect, the skin effect and the thermal effect of the pulse current to enable the workpiece 4 to reach a state more suitable for ultrasonic rolling surface strengthening treatment.

In this step S3, an operation needs to be performed while the operator stands on the insulating plate or the insulating pad to insulate the operator from the ground, and the operator needs to wear insulating gloves. The range of the pulse current output by the pulse power supply is 30A-400A, the range of the pulse frequency is 100 Hz-5000 Hz, and the range of the pulse width is 50 mu m-250 mu m; the temperature range for heating the workpiece 4 is 25-400 ℃.

S4, starting the ultrasonic control cabinet 10 of the ultrasonic rolling module, and setting the proper ultrasonic frequency, amplitude and lubricating oil quantity.

In step S4, the ultrasonic frequency range outputted from the ultrasonic control cabinet 10 is 10 to 40kHz, and the amplitude range is 1 to 14 μm. The gas pressure of the air compressor 11, i.e., the gas pressure of the cylinder 901 may be set as necessary.

S5, under the condition of keeping the pulse current, the ultrasonic rolling cutter 9 of the ultrasonic rolling module moves along the axial direction of the workpiece 4, and the surface of the workpiece 4 is subjected to pulse current auxiliary ultrasonic rolling surface strengthening treatment.

After step S5, the method may further include:

s6, adjusting the pulse current, the pulse frequency and the pulse width, keeping for a certain time, making the ultrasonic rolling cutter 9 move along the axial direction of the workpiece, and carrying out the pulse current auxiliary ultrasonic rolling surface strengthening treatment on the surface of the workpiece 4.

And S7, stopping the lathe, turning off the pulse power supply 1 and turning off the power supply of the ultrasonic control cabinet 10 after the work is finished, stopping lubricating oil, and discharging the gas in the cylinder 901 in the ultrasonic rolling cutter 9 to make the gas pressure zero.

And S8, after the workpiece 4 is cooled to a proper temperature, removing the workpiece 4.

In the steps S5 and S6, the number of times of performing the pulse current-assisted ultrasonic rolling on the surface of the workpiece 4 is 1 to 40 times.

Example 2:

the main characteristics of this embodiment are: an alternating current pulse welder, a pulse welder having a function of outputting an alternating current pulse current, or an alternating current welder is used to treat a workpiece with an alternating current pulse or an alternating current. The rest is the same as example 1.

Example 3:

the main characteristics of this embodiment are: the workpiece is processed by using a direct current pulse welder, a pulse welder having a function of outputting a direct current pulse current, or a direct current welder using a direct current pulse current or a direct current. The rest is the same as example 1.

Example 4:

the main characteristics of this embodiment are: and replacing the ultrasonic rolling tool with a turning tool, removing the ultrasonic control cabinet, insulating the turning tool from a lathe tool rest, and performing pulse current assisted turning on the workpiece by using the turning tool. The rest is the same as example 1.

Example 5:

the main characteristics of this embodiment are: the second chuck is removed and the first conductive member is brought into intimate contact with the first chuck, resulting in a two-chuck system. The rest is the same as example 1.

Example 6:

the main characteristics of this embodiment are: and removing the second chuck, and tightly contacting the first conductive piece with the first chuck to obtain a two-chuck system, wherein the two-chuck system is used for processing a workpiece by using an alternating current pulse electric welding machine, a pulse electric welding machine with a function of outputting alternating current pulses, or an alternating current electric welding machine. The rest is the same as example 2.

Example 7:

the main characteristics of this embodiment are: and removing the second chuck, and tightly contacting the first conductive piece with the first chuck to obtain a two-chuck system, wherein the two-chuck system is used for processing a workpiece by using direct current pulse electric welding machines, pulse electric welding machines with a function of outputting direct current pulse electric current, or direct current electric welding machines. The rest is the same as example 3.

Example 8:

the main characteristics of this embodiment are: and removing the second chuck, enabling the first conductive piece to be in close contact with the first chuck, enabling the system to be a two-chuck system, replacing the ultrasonic rolling cutter with a turning tool, removing the ultrasonic control cabinet, insulating the turning tool from a lathe tool rest, and performing pulse current assisted turning on the workpiece by using the turning tool. The rest is the same as example 4.

Example 9:

the main characteristics of this embodiment are: and the air cylinder in the ultrasonic rolling module is replaced by a hydraulic cylinder, the air compressor is replaced by a hydraulic pump, and the rolling ball body is pressed against the workpiece by using hydraulic pressure. The rest is the same as example 1.

In conclusion, the pulse power supply is connected with the conductive part, the pulse current is applied to the workpiece to be processed clamped by the clamping mechanism, and the electro-plastic effect, the skin effect and the thermal effect of the pulse current are utilized to reduce the resistance to plastic deformation of the surface layer of the metal material, so that the surface layer of the material is in a good plastic state, the material is more suitable for ultrasonic rolling surface strengthening treatment, and the strengthening effect of ultrasonic rolling can reach a deeper part of the material. And the obstruction effect of a hardened layer formed by last ultrasonic rolling on subsequent ultrasonic rolling strengthening in the process of multiple ultrasonic rolling can be overcome, and the ultrasonic rolling strengthening effect is enhanced. The reinforced layer can be thicker, the grains on the surface layer of the material are refined, even a nano layer is generated, the wear resistance, the corrosion resistance and the fatigue resistance of the surface layer of the material are improved, the comprehensive performance is more superior, and the reinforcing effect is superior to the single ultrasonic rolling reinforcing effect.

The invention has the following characteristics: 1) the invention is suitable for surface strengthening treatment of some metal materials with high hardness and poor plasticity and metal materials with serious work hardening, and can generate thicker strengthening layers on the surface layers. The blocking effect of the last strengthening layer on the next strengthening can be overcome and weakened, and the strengthening layer with better performance can be obtained. The method is suitable for the condition of less strengthening times and the condition of more strengthening times; 2) the surface of the material treated by the method has the advantages that the hardness is improved, the surface roughness is reduced, the surface appearance is improved, the residual compression stress is formed in the material, the surface strengthening layer is thicker, the surface of the material is more wear-resistant, corrosion-resistant and fatigue-resistant, and the comprehensive performance of the material is better than that of a single ultrasonic rolling strengthening effect; 3) the method is simple and easy to implement, is suitable for surface strengthening of shaft and rod parts, is suitable for surface treatment of various types of metal materials, and has simple structure, low cost and good effect compared with a special pulse power supply for surface strengthening.

The above description is only for the preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the inventive concept of the present invention within the scope of the present invention.