CN112894148A

CN112894148A - Processing equipment and processing method for preparing multi-stage microstructure

Info

Publication number: CN112894148A
Application number: CN202110058989.1A
Authority: CN
Inventors: 姚栋; 石广丰
Original assignee: Changchun University of Science and Technology
Current assignee: Changchun University of Science and Technology
Priority date: 2021-01-17
Filing date: 2021-01-17
Publication date: 2021-06-04
Anticipated expiration: 2041-01-17
Also published as: CN112894148B

Abstract

The invention relates to a processing device and a processing method for preparing a multi-stage microstructure, wherein the processing device comprises a workpiece, a base body, a coining assembly capable of being pressed into the surface of the workpiece, a driving piece for driving the coining assembly to move towards the workpiece, a laser generating device and a controller connected with the driving piece and the laser generating device, the coining assembly is provided with a through hole for laser of the laser generating device to pass through, and the controller controls the driving piece and the laser generating device to synchronously act; the processing method comprises the following steps: the driving piece drives the stamping assembly to be pressed into the surface of the workpiece to process a primary micro-pit structure on the surface of the workpiece; focusing laser of the laser generating device to the surface of the workpiece along the through hole to process a secondary micro-pit structure on the surface of the workpiece, and ablating the secondary micro-pit structure on the surface of the primary micro-pit structure; and processing a primary micro-pit structure on the surface of the workpiece and processing a secondary micro-pit structure on the surface of the workpiece synchronously. Through the technical scheme, the multistage micro-pit structure can be prepared simultaneously by matching the various devices, and the adverse effect of secondary processing on the surface of the one-stage micro-pit structure in the prior art is avoided.

Description

Processing equipment and processing method for preparing multi-stage microstructure

Technical Field

The invention relates to the technical field of processing of multilevel microstructures, in particular to processing equipment and a processing method for preparing a multilevel microstructure.

Background

In nature, many living beings can utilize body configuration and body surface morphology to reduce the resistance to exercise, so as to improve exercise performance, for example: fusiform of bird body, streamline of fish body, micro-groove structure of shark body surface, and micro-pit structure of dung beetle, shell and fish body surface. For observing and measuring a fish scale body surface structure of a fish body surface by adopting a Micro XAMTM white light interference three-dimensional shape, as shown in fig. 1, a micron-sized pit structure exists on the basis of the existing millimeter-sized pit structure, the micron-sized structure is called as a secondary microstructure, and related researches prove that the resistance reduction performance of the secondary and above microstructures is obviously superior to that of the primary microstructure, but the processing of the secondary and above microstructures is a difficult problem. At present, the primary micro-pits, micro-grooves, micro-protrusions and other micro-structural forms can be processed by using methods such as mechanical processing, grinding, electrochemistry and the like, and the secondary micro-structure is usually subjected to composite processing by using other processing methods after the primary micro-structure is formed, so that the process is complex, the cost is high, the period is long, and certain side effects on the surface quality of the original primary micro-structure are inevitably generated.

Disclosure of Invention

Solves the technical problem

In view of the above-mentioned disadvantages of the prior art, a first object of the present invention is to provide a processing apparatus for manufacturing a multi-level microstructure, which has a simple structure, and can simultaneously manufacture a multi-level microstructure at one time by using a plurality of devices in cooperation, thereby avoiding adverse effects on the surface of the primary microstructure due to secondary processing in the prior art.

The second purpose of the invention is to provide a processing method for preparing a multistage microstructure, which has high efficiency and high flexibility and can prepare a multistage microstructure with higher quality by one-time processing.

Technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme:

the processing equipment comprises a stamping assembly capable of being pressed into the surface of the workpiece, a driving piece used for driving the stamping assembly to move towards the workpiece, a laser generating device and a controller connected with the driving piece and the laser generating device, wherein the stamping assembly is provided with a through hole for laser of the laser generating device to pass through, and the controller controls the driving piece and the laser generating device to synchronously act so as to form the multilevel microstructure on the surface of the workpiece.

Furthermore, the coining assembly comprises a cutter bar, the upper end of the cutter bar is connected with the driving piece, and a cutter head is connected to the lower end of the cutter bar, and the through hole extends to the cutter head along the axial direction of the cutter bar.

Further, the through holes are formed in a plurality of the cutter bars, and the laser generating device can emit a plurality of groups of laser to propagate to the cutter head along each through hole, so that the multilevel microstructure at least comprises a primary micro-pit structure matched with the shape of the cutter head and a secondary micro-pit structure formed on the surface of the primary micro-pit structure.

Furthermore, a light splitter is arranged in the through hole, and the through hole is formed into a plurality of through holes uniformly arranged along the axis direction when extending to the light splitter, so that the multilevel microstructure at least comprises a primary micro-pit structure matched with the shape of the tool bit and a secondary micro-pit structure formed on the surface of the primary micro-pit structure.

Furthermore, an angle adjusting component is arranged on the cutter bar and used for controlling the verticality of the cutter bar and the cutter head.

Still further, the laser generating device comprises a laser, a collimator and a control panel, wherein the laser generates a laser beam which is guided to the collimator through a fiber optic cable, and the collimator transmits the laser to the coining assembly through a through hole.

A processing method for making a multi-level microstructure, the processing method comprising: processing a first-level micro-pit structure on the surface of a workpiece: the driving piece drives the stamping assembly to be pressed into the surface of the workpiece; processing a secondary micro-pit structure on the surface of a workpiece: focusing laser of the laser generating device to the surface of the workpiece along the through hole, and ablating a secondary micro-pit structure on the surface of the primary micro-pit structure; wherein the step of processing the primary micro-pit structure on the surface of the workpiece and the step of processing the secondary micro-pit structure on the surface of the workpiece are performed synchronously.

Furthermore, the stamping assembly is provided with a plurality of through holes in different forms, the laser emitted by the laser generating device correspondingly penetrates through each through hole, and a plurality of secondary micro-pit structures are simultaneously processed on the surface of the primary micro-pit while the primary micro-pit structures are processed on the surface of the workpiece.

Still further, the processing method further comprises: and adjusting the power, pulse frequency, spot radius and exposure time of the laser generating device, and ablating a micro-pit structure with more than three levels on the basis of the secondary micro-pit structure.

Furthermore, the power of the laser generating device is 3-200W, and the pulse is 30-200 kHz.

Advantageous effects

Compared with the known public technology, the technical scheme provided by the invention has the following beneficial effects:

according to the invention, the stamping assembly is driven to be pressed into the surface of a workpiece by the driving part, a primary micro-pit structure is processed on the surface of the workpiece, laser of the laser generating device is focused to the surface of the workpiece along the through hole, and a secondary micro-pit structure is ablated on the surface of the primary micro-pit structure; the step of processing the one-level micro-pit structure on the surface of the workpiece and the step of processing the second-level micro-pit structure on the surface of the workpiece are synchronously carried out, the second-level and above micro-pit structures can be prepared on the surface of the one-level micro-pit structure while the one-level micro-pit structure is prepared on the surface of the workpiece, and the multi-level micro-pit structure can be prepared simultaneously by matching of various devices, so that the adverse effect of secondary processing on the surface of the one-level micro-pit structure in the prior art is avoided.

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 obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a diagram of the appearance of micron-sized pits on the surface of a fish scale;

FIG. 2 is a schematic diagram of the fabrication apparatus of the present invention for making a multi-level microstructure;

FIG. 3 is a schematic view of the through hole inside the tool holder of the present invention;

FIG. 4 is a schematic diagram of the first and second stage dimple structures of the present invention;

FIG. 5 is a schematic diagram of a multi-level dimple structure of the present invention;

FIG. 6 is a diagram of simulation effect of preparing a multi-level structure by using simulation software Comsol according to the present invention.

The reference numerals in the drawings denote: 1-a substrate; 2-a workpiece; 3-the embossing assembly 4-the drive; 5-a laser generating device; 6-a controller; 21-a first-level micro-pit structure; 22-a secondary dimple structure; 31-an angle adjustment member; 32-a cutter bar; 33-a cutter head; 34-a through hole; 35-a light splitter; 51-a laser; 52-a collimator; 53-control panel.

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 to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The present invention will be further described with reference to the following examples.

As shown in fig. 2, in the present invention, a workpiece 2 is placed on a substrate 1, a driving member 4 drives an imprinting assembly 3 to be pressed into the surface of the workpiece 2 to form a micro-pit structure, a laser generating device 5 is disposed above the driving member 4, the driving member 4 and the laser generating device 5 are connected to a controller 6, and the controller 6 can precisely control the driving member 4 so as to precisely control the pressing amount, the pressing amount and the pressing rate of a tool bit 33, wherein two parameters of the pressing amount and the pressing rate have important influences on the formation and size of the micro-pit structure, and according to actual processing experience, a fine-quality micro-pit structure can be obtained when the pressing rate is set to 0.1 mm/s; meanwhile, the controller 6 can control the laser generator 5 to be turned on, and adjust parameters such as laser power and frequency. The embossing unit 3 further has a through hole 34 for allowing the laser emitted from the laser generator 5 to pass through, the arrow shown in fig. 2 and 3 is a laser, and the laser propagates along the through hole 34 to the cutting head 33, where the cutting head 33 may be a diamond cutting head, and the laser passes through the cutting head 33 and acts on the surface of the workpiece 2. The principle needs to be explained here from the theoretical and simulation point of view: in the process that laser passes through the tool bit, light reflection and refraction can occur, so when the laser passes through the tool bits with different structural forms and materials and is transmitted to the surface of a workpiece, energy loss exists, the energy loss is different, in addition, the laser reaches the surface of the workpiece through the tool bit, the size, the shape and the size precision of a light spot can be kept, enough strength is obtained, and then a secondary micro-pit structure with regular size and shape can be simultaneously prepared on the surface of the structural form of the primary micro-pit. Aiming at the problem, the invention provides an implementation mode, the tool bit is selected to be an axicon tool bit, simulation and simulation are carried out according to actual machining experience and finite element analysis software Comsol, the taper angle can be selected to be 80-130 degrees, three-dimensional Gaussian thermal load model simulation is established by using an analytic method, laser thermal load is applied right above the tool bit in the simulation process, the tool bit penetrates through the tool bit and acts on the surface of a workpiece, the same laser effect as the actual machining is realized, and parameters required to be set in the simulation process comprise influence factors such as selection of base materials, temperature control, duration influence and the like. The laser heat load and the light spot shape are displayed as shown in FIG. 6, a Fluke Ti400+ thermal imager is adopted for verification experiments, the Fluke Ti400+ thermal imager can accurately obtain a focusing image in the process of the imprinting experiment, the imprinting result is displayed, the temperature reading in the focusing image can also be accurately read, and according to simulation and multiple experimental verification, the size and the shape precision of the light spot can be ensured when the size and the verticality of the through hole and the power and the frequency of a laser generating device are well controlled, so that the size and the shape precision of the secondary micro-pit structure are controlled; in terms of light intensity, for a tool bit in an axicon structure form, an included angle of an axicon is theta, laser light is transmitted to a workpiece through the axicon tool bit, and a transmittance function passing through the tool bit can be represented as:

wherein n represents a refractive index, the diameter of the axicon lens is D,

k is 2 pi/lambda, lambda is the wavelength, and the diffraction field and the intensity of the laser after propagating to the axicon head can be written as follows by using a phase-stabilizing method according to the Fresnel diffraction theory:

in the formula:

the expression of the intensity is:

critical point Z_maxRepresents: z_max＝D/[2(n-1)θ]

The complex amplitude and the intensity of the laser have certain difference due to different ranges of the light field, and the laser intensity is controlled by controlling the diameter and the included angle of the axicon lens and the power and the frequency of the laser device, so that the size and the shape of the laser spot in the region behind the tool bit of the axicon lens are kept unchanged, and the laser spot has certain intensity.

The controller 6 in the present invention controls the driving member 4 and the laser generating device 5 to act synchronously to form a multi-level microstructure on the surface of the workpiece 2 at the same time. Specifically, the method comprises the following steps: as shown in fig. 1 and 4, the controller 6 controls the driving member 4 to drive the imprinting assembly 3 to press into the surface of the workpiece 2 to form the primary dimple structure 21, and at the same time, the controller 6 signals the laser generating device 5 to focus the laser emitted from the laser generating device 5 along the through hole 34 to the surface of the workpiece 2 through the tool tip 33, and the secondary dimple structure 22 is ablated on the surface of the primary dimple structure 21 by the huge energy generated by the laser, wherein the magnitude of the laser power is generally adjusted accordingly according to the material properties. The processing equipment and the method provided by the invention are easy to control, simple to operate and small in external influence factor, can simultaneously prepare the multi-stage microstructure at one time, and avoid the adverse effect of secondary processing on the surface of the primary microstructure in the prior art.

Specifically, in the present invention, the embossing assembly 3 includes a cutter bar 32 and a cutter head 33 connected to the lower end of the cutter bar 32, and the through hole 34 extends to the cutter head 33 along the axial direction of the cutter bar 32, so that the laser generated by the laser generating device 5 will propagate to the cutter head 33 through the through hole 34, and further act on the surface of the primary dimple structure 21 to form the secondary dimple structure 22. As shown in fig. 3, the through hole 34 may be formed as a plurality of through holes of different forms, through each of which the laser light emitted from the laser generating device 5 passes; thus, as shown in fig. 4, a plurality of secondary micro-pit structures 22 can be processed simultaneously with the primary micro-pit structure 21 on the surface of the work piece 2, as shown in fig. 3, the through hole 34 may be in the form of a plurality of through-holes 32, and, in particular, a plurality of through holes may be formed around the cutter bar 32 along the circumferential direction, and at this time, the laser generator 5 needs to be provided with a plurality of lasers 51 and collimators 52, so that a plurality of groups of lasers propagate to different positions of the cutter head 33 along each through hole, or only one set of laser generating device 5 is used, in which case a beam splitter 35 is provided in advance inside the through hole 34, such that the laser light will propagate through beam splitter 35 to tool tip 33 along the plurality of through-holes, such that the multi-level dimple pattern comprises at least one level of dimple pattern 21 that matches the shape of tool tip 33, and a plurality of secondary dimple structures 22 formed on the surface of the primary dimple structure 21 and uniformly arranged in the circumferential direction of the inner surface of the primary dimple structure 21.

In addition, in the present invention, the perpendicularity of the tool bit 33 has a large influence on the hole forming effect, so that the angle adjusting member 31 is mounted on the tool bar 32 for controlling the perpendicularity of the tool bar 32 and the tool bit 33. The invention provides an implementation case: the angle adjusting component is an NT06GM30 small-angle adjusting pitching platform, the appearance size is 25 multiplied by 25mm, the angle range is +/-30 degrees, the minimum adjusting amount is 0.5 degree, and the size and the shape of the pit can be accurately controlled through the adjustment of related parameters; except that the traditional round micro-pit structure can be obtained, when the inclination angle of the cutter head is printed on the surface of a workpiece by 10 degrees, 20 degrees and 30 degrees, the printing depth is 0.5mm, a fish scale type pit microstructure can be prepared, the fish scale type pit microstructure is in a variant oval structure form, and at the moment, if the laser generating device 5 acts simultaneously, a multi-stage micro-pit structure can be prepared on the surface of the fish scale type pit microstructure, and the specific mode is not repeated.

The laser generating device 5 comprises a laser 51, a collimator 52 and a control panel 53, wherein the control panel 53 is connected with the controller 6, the collimator 52 can ensure that laser is vertically irradiated into the through hole 34, and the control panel 53 is provided with a manual operation button which can directly control the laser 51 to act. As an optional implementation mode, the laser can be an infrared pulse ytterbium-doped fiber laser, and the laser has the advantages of large single pulse energy, high pulse frequency and the like, the power regulation range is 3-200W, and the pulse frequency range is 30-500 kHz; the laser beam generated by the laser 51 is connected to the collimator 52 through a fiber optic cable, and the collimator 52 transmits the laser light to the embossing assembly 3 through the through hole 34.

In the present invention, as shown in fig. 5, not only the secondary micro-pit structure can be prepared at one time, but also when the power and pulse frequency of the laser generator 5, the spot radius and the exposure time can be adjusted by the controller 6 or the control panel 53, especially the spot radius can be ablated to form three or more levels of micro-pit structures on the basis of the secondary micro-pit structure, and at this time, the relevant parameters of the laser generator 5 need to be strictly and accurately controlled.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A processing device for preparing a multi-stage microstructure, wherein a workpiece (2) is placed on a base body (1), the processing device is characterized by comprising an imprinting assembly (3) capable of being pressed into the surface of the workpiece (2), a driving member (4) for driving the imprinting assembly (3) to move towards the workpiece (2), a laser generating device (5), and a controller (6) connected with the driving member (4) and the laser generating device (5), the imprinting assembly (3) is provided with a through hole (34) for laser of the laser generating device (5) to pass through, and the controller (6) controls the driving member (4) and the laser generating device (5) to synchronously act so as to form the multi-stage microstructure on the surface of the workpiece (2).

2. The machining apparatus for making a multi-stage microstructure according to claim 1, wherein the embossing assembly (3) includes a tool bar (32) having an upper end connected to the driving member (4), and a tool bit (33) connected to a lower end of the tool bar (32), and the through hole (34) extends to the tool bit (33) in an axial direction of the tool bar (32).

3. The machining apparatus for producing a multilevel microstructure according to claim 2, wherein the through holes (34) are formed in a plurality through the tool bar (32), and the laser generating device (5) is capable of emitting a plurality of sets of laser light propagating along each through hole to the tool tip (33) so that the multilevel microstructure includes at least a primary dimple structure (21) matching the shape of the tool tip (33) and a secondary dimple structure (22) formed on the surface of the primary dimple structure (21).

4. The machining apparatus for producing a multilevel microstructure according to claim 2, wherein a beam splitter (35) is provided in the through hole (34), and the through hole (34) extends to the beam splitter (35) to form a plurality of through holes uniformly arranged in an axial direction, so that the multilevel microstructure includes at least a primary dimple structure (21) matching the shape of the tool tip (33) and a secondary dimple structure (22) formed on the surface of the primary dimple structure (21).

5. The machining apparatus for making a multi-stage microstructure according to claim 2, wherein the tool bar (32) has an angle adjusting member (31) mounted thereon for controlling verticality of the tool bar (32) and the tool bit (33).

6. The machining apparatus for producing a multi-stage microstructure according to claim 1, the laser generating device (5) comprising a laser (51), a collimator (52), a control panel (53), the laser (51) generating a laser beam directed to the collimator (52) through a fiber optic cable, the collimator (52) transmitting the laser to the embossing assembly (3) through a through hole (34).

7. A machining method for producing a multilevel microstructure, characterized in that a multilevel microstructure is formed on a surface of a workpiece (2) using the machining apparatus according to any one of claims 1 to 6, the machining method comprising:

processing a first-level micro-pit structure on the surface of a workpiece: the driving piece (4) drives the stamping assembly (3) to be pressed into the surface of the workpiece (2);

processing a secondary micro-pit structure on the surface of a workpiece: laser of the laser generating device (5) is focused to the surface of the workpiece (2) along the through hole (34), and a secondary micro-pit structure is ablated on the surface of the primary micro-pit structure; wherein the content of the first and second substances,

the step of processing the primary micro-pit structure on the surface of the workpiece and the step of processing the secondary micro-pit structure on the surface of the workpiece are carried out synchronously.

8. The processing method for making a multilevel microstructure according to claim 7, wherein the imprinting assembly (3) has a plurality of through holes of different forms, the laser light emitted from the laser generating device (5) passes through each of the through holes, and a plurality of secondary micro-pit structures are simultaneously processed on the primary micro-pit surface while the primary micro-pit structure is processed on the surface of the workpiece.

9. The processing method for making a multilevel microstructure according to claim 8, further comprising: and adjusting the power, pulse frequency, spot radius and exposure time of the laser generating device (5) to ablate a micro-pit structure with more than three levels on the basis of the secondary micro-pit structure.

10. The process for producing a multilevel microstructure according to claim 7, wherein the power of the laser generating device (5) is 3 to 200W and the pulse is 30 to 200 kHz.