CN115041996B

CN115041996B - Processing device and processing method for forming plane surface layer with gradient nano structure

Info

Publication number: CN115041996B
Application number: CN202210775292.0A
Authority: CN
Inventors: 吴世雄; 龚翔; 佘睿杰
Original assignee: Guangdong University of Technology
Current assignee: Guangdong University of Technology
Priority date: 2022-07-01
Filing date: 2022-07-01
Publication date: 2023-09-15
Anticipated expiration: 2042-07-01
Also published as: CN115041996A

Abstract

The application discloses a processing device and a processing method for forming a planar surface layer with a gradient nano structure, wherein the workpiece comprises the following components: the device comprises a cutter body, a processing workpiece, a workpiece rotating disc, a semi-closed cavity and a low-temperature jet nozzle, wherein the processing workpiece is placed in the workpiece rotating disc, the cutter body is in contact with the processing workpiece, the semi-closed cavity is arranged on the periphery of the workpiece rotating disc, and the low-temperature jet nozzle is connected with the semi-closed cavity. According to the application, the abrasion of the rear cutter surface of the cutting tool and the radius of the blade fillet are regulated, and then the low-temperature liquid nitrogen or the low-temperature carbon dioxide gas is sprayed to form a strong cooling low-temperature infiltration environment, so that a gradient nano tissue structure can be formed during processing of a high-hardness metal material. The processing device and the processing method for forming the planar surface layer with the gradient nano structure can be widely applied to the technical field of metal material cutting.

Description

Processing device and processing method for forming plane surface layer with gradient nano structure

Technical Field

The application relates to the technical field of metal material cutting, in particular to a processing device and a processing method for forming a planar surface layer with a gradient nano structure.

Background

The nano-structure metal material has excellent comprehensive mechanical property, physical property and chemical property, and in many industries such as aerospace, 3C, medical equipment, molds, automobiles, hardware and the like, if the grain size of the material can be thinned to the nano-scale through some heat treatment methods (solid solution strengthening, fine grain strengthening and the like), although the strength and the hardness are obviously improved, the plasticity and the toughness can be possibly reduced, but the application area of the material is greatly limited, if the material can form a gradient nano-structure, namely, the transition from surface layer nano-crystal to inner layer coarse grain structure is continuously increased, the high strength, the high toughness, the high hardness wear resistance and the good fatigue resistance can be realized; the existing technology for forming the gradient nano-structure surface layer mainly aims at the outer circular surface treatment of shaft parts, and the difficulty of realizing the gradient nano-surface layer in the existing technology is higher for certain metal materials with higher hardness (such as quenched steel).

Disclosure of Invention

In order to solve the technical problems, the application aims to provide a processing device and a processing method for forming a planar surface layer of a gradient nano structure, and a strong cooling low-temperature infiltration environment is constructed so that the gradient nano structure can be formed during processing of a high-hardness metal material.

In order to achieve the above object, the present application has the following technical scheme:

the utility model provides a processingequipment on formation gradient nanostructure plane top layer, includes cutter body, processing work piece, work piece carousel, semi-closed cavity and low temperature efflux nozzle, the processing work piece is placed in the work piece carousel, the cutter body is contacted with the processing work piece, semi-closed cavity installs in the periphery of work piece carousel, low temperature efflux nozzle is connected with semi-closed cavity, wherein:

the cutter body is used for carrying out plane cutting processing on a processed workpiece;

the processing workpiece is used for strengthening and generating a gradient nano-structure plane surface layer;

the workpiece turntable is used for placing and fixing a machined workpiece;

the semi-closed cavity is used for storing low-temperature cooling gas to form a strong cooling low-temperature infiltration environment;

the cryogenic jet nozzle is used for jetting cryogenic cooling gas.

Further, the cutter body comprises a front cutter and a rear cutter surface, the radius of the section fillet of the front cutter surface is 0.1-1 mm, and the abrasion loss of the rear cutter surface is regulated to be 0.1-1 mm.

Further, the cutter body comprises a hard alloy cutter for cutting, a PCBN cutter and a coating cutter.

Further, the contact point line speed between the processed workpiece and the cutter body is 50-800 m/min, and the cutting depth range of each processing is 10-3000 um.

Further, the semi-enclosed cavity forms include cylindrical and polygonal forms.

Further, the cryogenic cooling gas component injected by the cryogenic jet nozzle may also mix oil, water and nanoparticles.

Further, the material of the processing workpiece is a metal material.

Further, the planar surface gradient nanostructure of the machined workpiece specifically includes nano-sized grains, sub-micron sized grains, deformed grains, and original grain structure.

Further, the thickness of the gradient nanostructure of the plane surface layer of the processed workpiece is 5 um-3000 um.

Meanwhile, the application also provides a processing method for forming the planar surface layer of the gradient nano structure, which comprises the following steps:

s1, adjusting the radius of a front cutter and the abrasion loss of a rear cutter face of a cutter body by a sharpening method;

s2, mounting a machined workpiece on a workpiece turntable, enabling the tip of one end of a main cutting edge to be attached to the surface of the workpiece to perform tool setting treatment, and adjusting an included angle between a main cutting edge of a tool body and a plane of the workpiece to be machined to be 0-45 degrees;

s3, starting to rotate the central axis of the workpiece turntable until the workpiece turntable is in a vertical relation with the central axis, and spraying low-temperature cooling gas to the cutter body and the workpiece to be processed for more than two minutes;

s4, enabling the sprayed gas to flow into the semi-closed cavity, rotate, stay and soak the machined workpiece along with the machined workpiece, and testing the temperature of the knife tip and the ambient temperature near the workpiece by using a temperature sensor until a strong cooling low-temperature soaking environment is formed;

s5, based on the strong cooling low-temperature infiltration environment, the cutter starts to conduct feeding movement cutting treatment on the plane of the machined workpiece until the surface layer of the plane of the machined workpiece generates a gradient nano structure, and the cutting treatment on the plane of the machined workpiece is completed.

The method and the device thereof have the beneficial effects that: according to the application, by adjusting the abrasion of the rear cutter surface and the radius of the edge fillet of the cutting tool, a strong cooling low-temperature infiltration environment can be formed by spraying low-temperature liquid nitrogen or low-temperature carbon dioxide gas while processing high-hardness metal materials, the plastic deformation degree of the surface layer of a planar workpiece in the processing process is changed, the microstructures such as the thickness, the grain size and the like of the surface layer of the planar workpiece are adjusted, and a gradient nano structure is formed on the surface of the processed workpiece, so that the processed workpiece has higher mechanical property, the strength and the plasticity of the metal materials are improved, and the comprehensive performance of the materials is enhanced.

Drawings

FIG. 1 is a schematic structural view of a processing apparatus for forming a planar surface layer of a gradient nanostructure according to the present application;

FIG. 2 is a flow chart of the steps of a processing method of a processing apparatus for forming a planar surface layer of a gradient nanostructure according to the present application;

FIG. 3 is a cross-sectional scanning electron microscope view of a workpiece being processed in accordance with an embodiment of the present application;

FIG. 4 is a transmission electron microscope image of the external structure of the graded nano-surface layer of a work piece processed according to an embodiment of the application;

FIG. 5 is a schematic diagram of the grain size of the outer layer of the outer structure of the graded nano-surface layer of the work piece according to an embodiment of the present application under liquid nitrogen conditions;

FIG. 6 is a transmission electron microscope image of a middle structure of a graded nano-surface layer of a work piece processed in accordance with an embodiment of the present application;

FIG. 7 is a transmission electron microscope image of the internal structure of a graded nano-surface layer of a work piece processed in accordance with an embodiment of the present application;

FIG. 8 is a schematic diagram showing the corresponding cutting temperature variation of a machined workpiece at different cutting speeds according to the present application;

FIG. 9 is a schematic diagram showing the variation of the cutting temperature of a workpiece processed according to the present application under different cutting wear adjustments;

FIG. 10 is a schematic diagram of different strain conditions corresponding to different cutting speeds when the cutting wear of the machined workpiece is fixed;

FIG. 11 is a schematic diagram of different strain conditions corresponding to different amounts of cutting wear when the cutting speed of the machined workpiece is fixed.

Reference numerals: 1. a cutter body; 2. machining a workpiece; 3. a workpiece turntable; 4. a semi-enclosed cavity; 5. a low temperature jet nozzle.

Detailed Description

The application will now be described in further detail with reference to the drawings and to specific examples. The step numbers in the following embodiments are set for convenience of illustration only, and the order between the steps is not limited in any way, and the execution order of the steps in the embodiments may be adaptively adjusted according to the understanding of those skilled in the art.

Referring to fig. 1, the application provides a processing device for forming a planar surface layer with a gradient nano structure, which comprises a cutter body 1, a processing workpiece 2, a workpiece rotating disc 3, a semi-closed cavity 4 and a low-temperature jet nozzle 5, wherein the processing workpiece 2 is placed in the workpiece rotating disc 3, the cutter body 1 is in contact with the processing workpiece 2, the semi-closed cavity 4 is arranged on the periphery of the workpiece rotating disc 3, and the low-temperature jet nozzle 5 is connected with the semi-closed cavity 4.

The cutter body 1 is used for carrying out cutting processing on a processed workpiece 2, wherein the cutter body 1 comprises a front cutter and a rear cutter surface, the radius of a section fillet of the front cutter surface is 0.1-1 mm, and the abrasion loss of the rear cutter surface is regulated to be 0.1-1 mm; the tool body 1 includes a cemented carbide tool for cutting, a PCBN tool, and a coated tool.

The processing workpiece 2 is used for strengthening and generating a gradient nano structure, wherein the speed of a contact point line between the processing workpiece 2 and the cutter body 1 is 50-800 m/min, and the cutting depth range of each processing is 10-3000 um; the material of the processing workpiece 2 is a metal material, and can optionally comprise copper alloy, magnesium alloy, aluminum alloy, titanium alloy, steel, stainless steel and the like; the formation sequence of the surface gradient nano structure of the processed workpiece 2 is transited from nano-sized grains, submicron-sized grains and deformed grains to the original grain structure; the thickness of the gradient nano structure on the surface layer of the processed workpiece 2 is 5 um-3000 um.

The workpiece turntable 3 is used for placing and fixing the machined workpiece 2.

The semi-closed cavity 4 is used for storing gas to form a strong cooling low-temperature infiltration environment, wherein the form of the semi-closed cavity 4 can be cylindrical or other polygonal forms, and the low-temperature gas consumption can be increased in special occasions without using the semi-closed cavity 4 to surround the processing workpiece 2.

The cryogenic jet nozzle 5 is used for jetting cryogenic cooling gas, wherein the cryogenic liquid nitrogen or the cryogenic carbon dioxide component jetted by the cryogenic jet nozzle 5 can be mixed with oil, water and nano particles.

Meanwhile, referring to fig. 2, the application also provides a processing method for forming the planar surface layer of the gradient nano structure, which specifically comprises the following steps:

s1, adjusting the radius of a front cutter and the abrasion loss of a rear cutter face of a cutter body 1 by a sharpening method;

s2, mounting the machined workpiece 2 on a workpiece turntable 3, enabling the tip of one end of a main cutting edge to be attached to the surface of the workpiece to perform tool setting treatment, and adjusting an included angle between the main cutting edge of the tool body 1 and the plane of the workpiece 2 to be machined to be 0-45 degrees;

s3, starting to rotate the central axis of the workpiece turntable 3 until the workpiece turntable 3 is in a vertical relation with the central axis, and spraying low-temperature cooling gas to the cutter body 1 and the workpiece 2 for more than two minutes;

s4, enabling the sprayed gas to flow into the semi-closed cavity 4, rotate along with the machined workpiece 2, stay and soak the machined workpiece 2, and testing the temperature of the knife tip and the ambient temperature near the workpiece by using a temperature sensor until a strong cooling low-temperature soaking environment is formed;

s5, based on a strong cooling low-temperature infiltration environment, the cutter starts to perform feeding movement cutting treatment on the plane of the machined workpiece 2 until the surface layer of the plane of the machined workpiece 2 generates a gradient nano structure, and the cutting treatment on the plane of the machined workpiece 2 is completed.

Specifically, the cutting tool before cutting is used for adjusting the radius of a section fillet of a main cutting edge to be 0.1-1 mm in a sharpening mode and the like, adjusting the abrasion loss of a rear cutter surface to be 0.1-1 mm, installing a metal workpiece on a rotary table, installing a semi-closed cavity 4 around the rotary table, clamping the cutting tool, adjusting the main cutting edge of the cutting tool to an included angle of 0-45 degrees with a processed plane, starting to rotate around an axis, enabling the plane to be processed to be perpendicular to the axis, spraying low-temperature liquid nitrogen or low-temperature carbon dioxide on the front cutter surface and the rear cutter surface of the cutting edge for more than 2 minutes, and enabling gas to rotate, stay and soak the workpiece along with the workpiece in the semi-closed cavity 4 to form a strong cooling low-temperature infiltration environment; continuously spraying low-temperature liquid nitrogen or low-temperature carbon dioxide, starting the planar cutting processing of the workpiece, namely, feeding the cutter from the outside of the turntable towards the center, cutting the plane of the workpiece 2, and strengthening the surface layer material below the plane of the workpiece in cutting to form a gradient nano structure.

The first embodiment of the application is as follows:

the machined workpiece 2 is made of quenched steel, the radius of a section fillet of a main cutting edge is adjusted to be 0.15mm by a cutter before cutting machining in a sharpening mode and the like, and the abrasion loss of a rear cutter surface is adjusted to be 0.15mm; installing a workpiece made of quenched steel material on the turntable, and installing a semi-closed cavity 4 around the turntable; clamping the cutter and adjusting the main cutting edge of the cutter to an included angle of 5 degrees with the machined plane; the metal workpiece to be processed and the turntable start to rotate around an axis, the rotation linear speed or the cutting speed is 430 meters/min, and the plane to be processed is perpendicular to the axis; spraying low-temperature liquid nitrogen on the front and rear cutter surfaces of the cutting edge, and enabling gas to rotate, stay and soak the workpiece along with the workpiece in the semi-closed cavity 4, wherein the process lasts for more than 10 minutes before cutting processing, so that the cutter and the surrounding of the workpiece are subjected to infiltration type strong cooling; continuously spraying low-temperature liquid nitrogen to start the plane cutting processing of the workpiece, and performing feeding motion of a hard alloy cutter for cutting from the outside of the turntable towards the center to cut the plane of the workpiece 2, wherein the surface layer material below the plane of the workpiece is reinforced in cutting to form a gradient nano structure;

as shown in fig. 3, in order to process a cross-sectional electron microscope image of the workpiece 2, the transition condition of nanocrystalline-sub-nanocrystalline-original crystal on the surface layer of the workpiece can be seen, and obvious gradient change is formed;

as shown in fig. 4, a transmission electron microscope image of the external structure of the gradient nano-surface layer of the work piece 2 can be seen, wherein the nano-crystal grain and the electron diffraction pattern are in a semi-continuous ring shape;

as shown in FIG. 5, the grain size of the outer layer under liquid nitrogen conditions is about 100nm;

as shown in fig. 6, in a transmission electron microscope image of the middle structure of the gradient nano-surface layer of the work piece 2, it can be seen from the electron diffraction pattern in the image that the diffraction ring in the middle has no diffraction of the outermost layer, which means that the grain size in the middle of the layer is larger;

as shown in fig. 7, a transmission electron microscope image of the internal structure of the gradient nanoskin of the work piece 2 is processed, and it can be seen from the electron diffraction pattern that the continuity or integrity of the internal diffraction ring is further reduced, which indicates that the internal grain size is further increased;

as shown in fig. 8, the cutting temperature of the workpiece is changed correspondingly under different cutting speeds;

as shown in fig. 9, the cutting temperature of the workpiece is changed correspondingly under different cutting wear adjustment;

as shown in fig. 10, the workpiece is processed under different strain conditions corresponding to different cutting speeds when the cutting wear is fixed;

as shown in fig. 11, the workpiece is processed at a fixed cutting speed, and the different strain conditions are associated with different amounts of cutting wear.

The content in the method embodiment is applicable to the system embodiment, the functions specifically realized by the system embodiment are the same as those of the method embodiment, and the achieved beneficial effects are the same as those of the method embodiment.

While the preferred embodiment of the present application has been described in detail, the application is not limited to the embodiment, and various equivalent modifications and substitutions can be made by those skilled in the art without departing from the spirit of the application, and these equivalent modifications and substitutions are intended to be included in the scope of the present application as defined in the appended claims.

Claims

1. The utility model provides a processingequipment on formation gradient nanostructure plane top layer, its characterized in that includes cutter body, processing work piece, work piece carousel, semi-closed cavity and low temperature jet nozzle, the processing work piece is placed in the work piece carousel, the cutter body contacts with the processing work piece, semi-closed cavity installs in the periphery of work piece carousel, low temperature jet nozzle is connected with semi-closed cavity, wherein:

the workpiece turntable is used for placing and fixing a machined workpiece;

the low-temperature jet nozzle is used for jetting low-temperature cooling gas;

the cutter body comprises a front cutter surface and a rear cutter surface, the radius of a section fillet of the front cutter surface is 0.1-1 mm, and the abrasion loss of the rear cutter surface is regulated to be 0.1-1 mm;

and adjusting the radius of the front cutter face and the abrasion loss of the rear cutter face of the cutter body by a sharpening method.

2. A machining device for forming a planar surface layer of a gradient nano structure according to claim 1, wherein the cutter body comprises a cemented carbide cutting tool, a PCBN cutting tool and a coated cutting tool.

3. The processing device for forming a planar surface layer with a gradient nano structure according to claim 1, wherein the contact point line speed between the plane of the processed workpiece and the cutter body is 50-800 m/min, and the cutting depth of each processing is 10-3000 um.

4. The processing apparatus for forming a planar surface layer of a gradient nanostructure of claim 1, wherein the semi-enclosed cavity comprises a cylindrical surface and a polygonal shape.

5. The processing apparatus for forming a planar surface layer of a gradient nanostructure of claim 1, wherein the cryogenic cooling gas component injected by the cryogenic jet nozzle further mixes oil, water and nanoparticles.

6. A processing apparatus for forming a planar surface layer of a gradient nanostructure as set forth in claim 3, wherein said material of said work piece is a metallic material.

7. The apparatus of claim 6, wherein the planar surface gradient nanostructures of the workpiece comprise nano-sized grains, sub-micron sized grains, deformed grains, and primary grain structure.

8. The processing apparatus for forming a planar surface layer of a gradient nanostructure of claim 7, wherein the planar surface layer of the processed workpiece has a gradient nanostructure thickness of 5um to 3000um.

9. The processing method for forming the planar surface layer of the gradient nano structure is characterized by comprising the following steps of:

s1, adjusting the radius of a front cutter face and the abrasion loss of a rear cutter face of a cutter body by a sharpening method;

the radius of the section fillet of the front cutter surface is 0.1-1 mm, and the abrasion loss of the rear cutter surface is regulated to be 0.1-1 mm;