BIONIC AUSTRALIAN THORNY DEVIL GRINDING WHEEL, GRINDING DEVICE, AND PREPARATION PROCESS
20250196293 ยท 2025-06-19
Assignee
Inventors
- Teng GAO (Shandong, CN)
- Changhe LI (Shandong, CN)
- Yuxiang SONG (Shandong, CN)
- Xiaoming Wang (Shandong, CN)
- Min YANG (Shandong, CN)
- Yuying YANG (Shandong, CN)
- Jingang SUN (Shandong, CN)
- Runze LI (Shandong, CN)
- Yunze LONG (Shandong, CN)
Cpc classification
B24D18/0072
PERFORMING OPERATIONS; TRANSPORTING
International classification
B24D5/10
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The present disclosure provides a bionic Australian thorny devil grinding wheel, a grinding device, and a preparation process, and relates to the field of grinding equipment. For the problem of the poor effect of conveying grinding fluid by a grinding wheel at present, imitating semi-open capillary channels and a honeycomb structure on the skin of the Australian thorny devil, prisms with isosceles trapezoidal bottom surfaces are arranged on a matrix in sequence to form directional liquid self-conveying flow channels and a superhydrophilic honeycomb-like hexagonal distribution structure.
Claims
1. A bionic Australian thorny devil grinding wheel, comprising: a matrix, having a superhydrophobic layer arranged on an outer peripheral surface; and abrasive grains which are prismatic with an isosceles trapezoidal bottom surface, wherein an axis of the abrasive grain is distributed in a radial direction of the matrix, one end of the abrasive grain in an axial direction is connected to the outer peripheral surface of the matrix, and the other end is of a hydrophilic structure; and two adjacent abrasive grains are arranged at intervals to form a hexagonal-prism-shaped abrasive grain cluster, and gaps are reserved between adjacent abrasive grain clusters, such that a hexagonal surrounding flow channel is formed in a circumferential direction of each abrasive grain cluster.
2. The bionic Australian thorny devil grinding wheel according to claim 1, wherein the outer peripheral surface of the matrix is covered with the abrasive grain clusters arranged in array, and the abrasive grain clusters are arranged in a honeycomb-like hexagon.
3. The bionic Australian thorny devil grinding wheel according to claim 2, wherein along a circular direction of the outer peripheral surface of the matrix, the abrasive grain clusters are arranged at intervals into a plurality of columns, and adjacent columns of the abrasive grain clusters are staggered.
4. The bionic Australian thorny devil grinding wheel according to claim 1, wherein a middle flow channel is formed between two abrasive grains of the abrasive grain cluster, and the middle flow channel is located between side surfaces of corresponding isosceles trapezoid bottom edges of the two abrasive grains.
5. The bionic Australian thorny devil grinding wheel according to claim 4, wherein the middle flow channel is tangentially distributed along a position of the outer peripheral surface of the matrix, and communicates with the surrounding flow channel.
6. The bionic Australian thorny devil grinding wheel according to claim 5, wherein both the middle flow channel and the surrounding flow channel are semi-open capillary channels to exert capillary action with a tendency toward a hydrophilic structure to water inside the middle flow channel and the surrounding flow channel.
7. The bionic Australian thorny devil grinding wheel according to claim 1, wherein the abrasive grains are chamfered corresponding to side ridges of prisms.
8. A grinding device, comprising the bionic Australian thorny devil grinding wheel according to claim 1.
9. A process for preparing the bionic Australian thorny devil grinding wheel according to claim 1, comprising: performing superhydrophobic treatment on the outer peripheral surface of the matrix to obtain the superhydrophobic layer; processing the abrasive grains, such that the hydrophilic structure is formed at the one end of the abrasive grain; and pairing the abrasive grains to obtain the abrasive grain clusters, adhering the abrasive grains to the outer peripheral surface of the matrix in a manner of the abrasive grain clusters, arranging the adjacent abrasive grain clusters at intervals, and forming a bionic Australian thorny devil flow channel between adjacent abrasive grains, wherein the abrasive grain clusters are arranged in a bionic honeycomb structure.
10. The process for preparing the bionic Australian thorny devil grinding wheel according to claim 9, wherein a masking method is adopted to adhere the abrasive grains to the matrix.
11. The bionic Australian thorny devil grinding wheel according to claim 9, wherein the outer peripheral surface of the matrix is covered with the abrasive grain clusters arranged in array, and the abrasive grain clusters are arranged in a honeycomb-like hexagon.
12. The bionic Australian thorny devil grinding wheel according to claim 11, wherein along a circular direction of the outer peripheral surface of the matrix, the abrasive grain clusters are arranged at intervals into a plurality of columns, and the adjacent columns of the abrasive grain clusters are staggered.
13. The bionic Australian thorny devil grinding wheel according to claim 9, wherein a middle flow channel is formed between two abrasive grains of the abrasive grain cluster, and the middle flow channel is located between side surfaces of corresponding isosceles trapezoid bottom edges of the two abrasive grains.
14. The bionic Australian thorny devil grinding wheel according to claim 13, wherein the middle flow channel is tangentially distributed along a position of the outer peripheral surface of the matrix, and communicates with the surrounding flow channel.
15. The bionic Australian thorny devil grinding wheel according to claim 14, wherein both the middle flow channel and the surrounding flow channel are semi-open capillary channels to exert capillary action with a tendency toward a hydrophilic structure to water inside the middle flow channel and the surrounding flow channel.
16. The bionic Australian thorny devil grinding wheel according to claim 9, wherein the abrasive grains are chamfered corresponding to side ridges of prisms.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and descriptions thereof are used to explain the present disclosure, and do not constitute an improper limitation of the present disclosure.
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035] 1bionic Australian thorny devil grinding wheel, 2matrix, 3abrasive grain cluster, 4grinding wheel guard, 5minimum quantity lubrication nozzle, 6grinding fluid conveying pipeline, 7compressed air conveying pipeline, 8ultrasonic vibrator, 9laser device, 10laser beam, 11beam expander, 12reflector, 13aperture, 14Glan prism, 15focus lens, and 16movable machining platform.
DESCRIPTION OF THE EMBODIMENTS
Embodiment 1
[0036] In a typical embodiment of the present disclosure, as shown in
[0037] The bionic Australian thorny devil grinding wheel 1 is described in detail in conjunction with accompanying drawings.
[0038] Referring to
[0039] Additionally, a middle flow channel is formed between two abrasive grains of the abrasive grain cluster 3, and the middle flow channel is located between side surfaces of corresponding isosceles trapezoid bottom edges of the two abrasive grains. The middle flow channel is tangentially distributed along the position of the outer peripheral surface of the matrix 2, and communicates with the surrounding flow channel.
[0040] In this embodiment, both the middle flow channel and the surrounding flow channel are semi-open capillary channels to exert capillary action with a tendency toward the hydrophilic structure to water inside the middle flow channel and the surrounding flow channel.
[0041] It should be noted that the middle flow channel and the surrounding flow channel adopt a structure mimicking surface of Australian thorny devil. A top end of each skin bulge of the Australian thorny devil is a hydrophilic zone without covering a wax layer, and other zones of a back portion are waxy hydrophobic zones. In this embodiment, the superhydrophobic layer on the outer peripheral surface of the matrix 2 is the hydrophobic zone, and the hydrophilic structure at the tail end of the abrasive grain is the hydrophilic zone. Droplets are adsorbed after making contact with the hydrophilic zone, causing the droplets in the hydrophilic zone to quickly grow to play a role of water collection. Meanwhile, microscopic capillaries on the skin of the Australian thorny devil can guide liquid to specific locations, just like the middle flow channel and the surrounding flow channel in this embodiment, which guide the water to the hydrophilic zone from the hydrophobic zone, thereby achieving directional transport.
[0042] The outer peripheral surface of the matrix 2 utilizes the superhydrophobic layer treated by silicon oil-thermal processing. The matrix 2 with the superhydrophobic layer and the hydrophilic abrasive grains act together to improve the cooling and lubricating efficiency.
[0043] The outer peripheral surface of the matrix 2 is covered with the abrasive grain clusters 3 arranged in array. As shown in
[0044] By designing the grinding wheel matrix 2 and the abrasive grains, the middle flow channel and the surrounding flow channel are formed in the outer peripheral surface of the matrix 2, thereby limiting surface tension of the liquid. As shown in
[0045] The self-conveying principle of the grinding fluid in this embodiment is as follows:
[0046] As shown in
[0047] The middle flow channel and the surrounding flow channel are the same in structure, and are collectively referred to as flow channels in subsequent analysis.
[0048] In the formula, F.sub.L and F.sub.C respectively denote the driving force Laplace pressure and the single flow channel capillary force during droplet conveying; F.sub.H denotes the hysteresis resistance that the droplets need to overcome during conveying; and F.sub.G denotes the droplet gravity.
[0049] Different contact areas result in different contact angles on front and back sides of the droplets, leading to the generation of the Laplace pressure F.sub.L.
[0050] F.sub.L is shown in the formula (1):
[0051] In the formula, denotes the surface tension of water; L.sub.TCL denotes the length (m) of a three-phase contact line; and .sub.f and .sub.b respectively denote the front contact angle and the back contact angle of the droplets.
[0052] The single flow channel capillary force F.sub.C is shown in the formula (2):
[0053] In the formula, a denotes the flow channel width (m); h denotes the microtexture flow channel height (m); and denotes the surface contact angle of the droplets.
[0054] During droplet conveying, the hysteresis resistance F.sub.H that the droplets need to overcome is shown in the formula (3):
[0055] In the formula, C.sub.D denotes the drag coefficient; denotes the density (g/cm.sup.3) of the droplets; denotes the conveying rate (cm/s); and A denotes the cross-sectional area (cm.sup.2) of the droplets.
[0056] The droplet gravity F.sub.G is shown in the formula (4):
[0057] As the size of the microdroplets increases, the droplet conveying rate is reduced, resulting in a decrease in hysteresis resistance F.sub.H. Simultaneously, the front contact angle .sub.f of the liquid and the length L.sub.TCL of the three-phase contact line are increased, and the back contact angle .sub.b is reduced. The Laplace pressure F.sub.L is increased, and the driving force exerted on the droplets is greater than the resistance, i.e., F=F.sub.L+F.sub.CF.sub.HF.sub.G>0, achieving droplet self-conveying.
[0058] In this embodiment, the hydrophilization principle of the abrasive grain clusters 3 arranged on the bionic Australian thorny devil grinding wheel 1 in a honeycomb-like hexagon is as follows: [0059] according to a Cassie model,
[0060] In the formula, f.sub.LS and f.sub.LV respectively denote the area fractions of a liquid-solid contact interface and a liquid-gas contact interface, where f.sub.LS+f.sub.LV=1. .sub.LS and .sub.LV respectively denote the liquid-solid contact angle and the liquid-gas contact angle.
[0061] Compared with a conventional structure surface, the honeycomb-like hexagonal structure increases the solid-liquid contact area, and the three-phase contact line of the droplets on the surface of the structure changes, thereby increasing the Laplace pressure in the droplets, driving the droplets to spread, reducing the surface contact angle, and keeping physical stability of a liquid film.
[0062] The abrasive grains are chamfered corresponding to side ridges of prisms. Meanwhile, the droplets on the surface of the honeycomb-like hexagonal structure can diffuse all around along the flow channel to overcome the resistance generated by pinning of the three-phase contact line, such that the surface of the bionic Australian thorny devil grinding wheel 1 has super hydrophilicity, the grinding fluid stays on the surface of the bionic Australian thorny devil grinding wheel 1, and the physical stability of the liquid film is kept.
Embodiment 2
[0063] In a typical embodiment of the present disclosure, as shown in
[0064] The bionic Australian thorny devil grinding wheel 1 in Embodiment 1 is utilized.
[0065] The bionic Australian thorny devil grinding wheel 1 is externally provided with a grinding wheel guard 4. A minimum quantity lubrication nozzle 5 is connected to a grinding fluid conveying pipeline 6 and a compressed air conveying pipeline 7. A grinding fluid source is connected to the grinding fluid conveying pipeline 6. The compressed air conveying pipeline 7 is connected to a pressure air source.
[0066] Ultrasonic vibration enhances the infiltrating property of the grinding fluid on the bionic grinding wheel and the convective heat transfer coefficient of the grinding fluid, thereby enhancing the heat transfer capacity and lubricating capacity of cooling liquid. As shown in FIG. 2, one side of a tangential amplitude-changing mechanism of an ultrasonic vibrator 8 is connected to a radial amplitude changing mechanism, and the other side is connected to the workpiece. The radial amplitude changing mechanism and the tangential amplitude changing mechanism act together to form vibration of an arc track. By adjusting operating parameters of the radial amplitude changing mechanism and the tangential amplitude changing mechanism, a ground surface can be more uniform. Meanwhile, droplets staying on the surface subjected to ultrasonic vibration can explode into micro-mists of smaller droplets or form stable capillary waves on the surface, thereby enhancing the infiltrating characteristics of the grinding fluid.
[0067] The principle of enhancing the infiltrating of the grinding fluid by adding ultrasound in this embodiment is as follows:
[0068] According to the Jurin's law, the infiltrating height h.sub.m of the grinding fluid without adding ultrasound is shown in the formula (6):
[0069] In the formula, h.sub.m denotes the height (m) of liquid infiltration, denotes the surface tension of liquid, denotes the contact angle, denotes the liquid density (Kg/m3), g denotes the gravitational acceleration (m/s2), and r denotes the width (m) of the middle flow channel and the surrounding flow channel.
[0070] After the addition of ultrasound, high-frequency and small-amplitude vibration is generated by ultrasonic waves, which in turn generates an extrusion die effect.
[0071] The additional static pressure intensity under the extrusion die effect is shown in the formula (7):
[0072] In the formula, denotes the extrusion die constant, u denotes the sound velocity (m/s), A.sub.0 denotes the amplitude (dB) of ultrasonic waves, and d.sub.0 denotes the liquid level height (m).
[0073] The infiltrating height h.sub.j under the extrusion die effect is shown in the formula (8):
[0074] The total infiltrating height h.sub.c of the cooling liquid after adding ultrasound is shown in the formula (9):
[0075] Under the action of ultrasound, the total liquid infiltrating height is the sum of the original infiltrating height and the infiltrating height under the extrusion die effect, thereby further enhancing the conveying performance of the grinding fluid.
[0076] The principle of enhancing the heat transfer performance of the grinding fluid by adding ultrasound in this embodiment is as follows: [0077] under the action of ultrasound, local tensile stress occurs in the cooling liquid, which forms a negative pressure. The decrease in pressure intensity causes gas dissolved in the grinding fluid to become supersaturated, escaping from the fluid and forming small bubbles. Under the action of the strong tensile stress, gas forms cavities within the fluid after escaping, which is referred to as an ultrasonic cavitation effect. The ultrasonic cavitation effect includes generation, expansion, oscillation, and collapse of cavitation bubbles. A large amount of energy can be released at the moment of cavitation bubble collapse. The impact effect generated by the energy is much greater than the impact effect of grinding, causing disturbances on a grinding flow field. The surface flow field of the workpiece transitions from laminar flow to turbulent flow, leading to an increase in the Reynolds number of the fluid.
[0078] The convective heat transfer coefficient h of the fluid is shown in the formula (10):
[0079] In the formula, N.sub.u denotes the Nusselt number of the fluid, k denotes thermal conductivity (W/(mk)), and L denotes the geometric length (m) of a heat transfer surface.
[0080] The Nusselt number N.sub.u of the fluid is shown as:
[0081] In the formula, Re denotes the Reynolds number, and Pr denotes the Prandtl constant.
[0082] From the formulas (10) to (11), it can be observed that as the Reynolds number increases, the Nusselt number of the fluid increases, leading to an increase in the convective heat transfer coefficient of the fluid.
[0083] The minimum quantity lubrication nozzle 5 conveys the grinding fluid to a grinding zone in a mist spray manner. The hydrophilic abrasive grain clusters 3 on the surface of the bionic Australian thorny devil grinding wheel 1 first make contact with an atomized cooling medium. Based on a basic wettability principle, the cooling medium first condenses into microdroplets on the abrasive grain clusters 3, and the cooling medium not contact with the abrasive grain clusters 3 is sprayed onto the outer peripheral surface of the matrix 2 and is conveyed to the hydrophilic structure at the tail end of the abrasive grains through the middle flow channel and the surrounding flow channel to accelerate growth of the droplets at the abrasive grain clusters 3. Then, the droplets fall off under the gravity and the rotation of the bionic Australian thorny devil grinding wheel 1.
Embodiment 3
[0084] In another typical implementation of the present disclosure, as shown in
[0085] The bionic Australian thorny devil grinding wheel 1 in Embodiment 1 is obtained by the preparation process. The preparation process includes: [0086] superhydrophobic treatment is performed on an outer peripheral surface of a matrix 2 to obtain a superhydrophobic layer; [0087] abrasive grains are processed, such that a hydrophilic structure is formed at one end of the abrasive grain; and [0088] the abrasive grains are paired to obtain abrasive grain clusters 3, the abrasive grains are adhered to the outer peripheral surface of the matrix 2 in a manner of the abrasive grain clusters 3, the adjacent abrasive grain clusters 3 are arranged at intervals, and a bionic Australian thorny devil flow channel is formed between the adjacent abrasive grains, and the abrasive grain clusters 3 are arranged in a bionic honeycomb structure.
[0089] Specifically, as shown in
1. Super-Hydrophobization on a Surface of the Grinding Wheel Matrix 2
[0090] A superhydrophobic coating is arranged on the outer peripheral surface of the matrix 2, silicon oil-thermal processing is adopted for super-hydrophobization, the coating of the matrix 2 is sequentially placed in acetone, anhydrous ethanol, and deionized water for ultrasonic cleaning for 5 min each, and then, a sample is dried for use later. Then, a silicon oil solution is dropwise added and dipped into a surface of the coating of the matrix 2, and the surface is placed on a heating plate to be heated for 10 min to ensure stable bond between the silicon oil and the surface. Through the silicon oil-thermal processing, functional groups with low surface energy in the silicon oil are deposited on the surface of the coating of the matrix 2 to form a hydrophobic layer, such that a contact angle of the grinding fluid on the matrix 2 is greater than 150 degrees, exhibiting excellent superhydrophobic performance.
2. Surface Groove Machining on the Matrix 2
[0091] As shown in
[0092] Before the start of preparation, the matrix 2 is sequentially placed in acetone, anhydrous ethanol, and deionized water for ultrasonic cleaning for 5 min each, and then a sample is dried for use later. Selected laser parameters are as follows: the wavelength is 1064 nm, the pulse width is 45 ns, the power is 15 W, the frequency is 20 kHz, and the scanning speed is 100 mm/s. By increasing the number of times of laser scanning, the texture depth is increased. By adjusting various parameters of the laser, the matrix 2 is machined into a honeycomb-like hexagonal structure to keep the physical stability of a water film.
3. Abrasive Grain Hydrophilization
[0093] As shown in
[0094] Diamond abrasive grains of the same size and the similar structure are selected, and surfaces of the diamond abrasive grains are roughened by soaking in chromic acid. According to the Young wetting equation:
[0095] denotes the surface roughness, and based on the equation, it can be deduced that an increase in leads to a decrease in contact angle, thereby enhancing hydrophilicity. The roughened diamond abrasive grains exhibit hydrophilicity.
4. Combination of the Abrasive Grain Clusters 3 and the Hydrophobic Layer on the Surface of the Matrix 2
[0096] The electroplated abrasive grains are orderly arranged using a masking method, and a coordinate equation for the center of each abrasive grain cluster 3 is shown in the formula (13):
[0097] .sub.ij denotes the abrasive grain misalignment angle; i denotes the circumferential row number, and j denotes the axial row number (i=1, 2, 3, . . . , and M; and j=1, 2, . . . , and H/a); a denotes the abrasive grain spacing (mm); N denotes the total number of the abrasive grains; M denotes the circumferential total row number of the abrasive grains; Z.sub.ij denotes the axial coordinates; and r.sub.S denotes the grinding wheel radius, and H denotes the abrasive grain protrusion height.
[0098] A mask with array holes arranged orderly is formed through laser processing, and the mask is adhered to the matrix 2. Before adhering the mask, the surface of the matrix 2 is first subjected to degreasing and rust removal processes such as chemical degreasing, electrochemical degreasing, and acid pickling, thereby preventing the electroplated surface of the matrix 2 from being contaminated again.
[0099] Then, the abrasive grain clusters 3 are fixed into the orderly-arranged array holes through a binder. The thickness of the binder is 20% of the height of the diamond abrasive grains. The abrasive grains in each hole form the abrasive grain clusters 3.
[0100] The holes are in a shape of an inverted bowl, i.e., a big-end-down shape. This stacking shape provides a higher holding force for the abrasive grains, and it is not easy for the abrasive grains to fall off during operation. Through an electrodeposition method, the abrasive grains are preliminarily fixed, the mask is removed, and then electroplating for thickening is performed. The electro-deposited matrix 2 is subjected to ultrasonic cleaning for 5 min first, then, electroplate liquid is poured into an electroplating tank washed cleanly, and the pH value of the electroplate liquid is 3.0-5.0. In the electroplating process, a magnetic stirrer is adopted for continuous stirring, the electroplating time is 10 min, such that the coating thickness of an electroplated coating is 60% of the diameter of the abrasive grains, and the abrasive grain protrusion height is about of the total height of the abrasive grains.
[0101] The abrasive grain clusters 3 are arranged in a hydrophilic bionic honeycomb hexagon. Due to the hexagonal structure, the surface of the grinding wheel has superhydrophilicity, thereby making water stay on the surface of the grinding wheel without volatilization and keeping the physical stability of a liquid film.
[0102] The foregoing descriptions are merely preferred embodiments of the present disclosure, but are not intended to limit the present disclosure. Those skilled in the art may make various modifications and variations to the present disclosure. Any modification, equivalent replacement, improvement, and the like made within the spirit and principle of the present disclosure shall fall within the scope of protection of the present disclosure.