Method for polishing irregular superhard material surfaces

Abstract

The application discloses a polishing method for irregular superhard material surfaces and relates to the technical field of precision machining of superhard brittle materials, and the method comprises the following steps: sequentially performing ultrasonic cleaning, rinsing and drying treatment on an initial workpiece to be polished to obtain a first workpiece to be polished; adding target beef tallow, 5-8 wt% of a nano-alumina dispersant and 0.1-0.3 wt% of sodium dodecyl benzene sulfonate into a high-speed shearing emulsifier respectively for stirring treatment; uniformly applying the homogeneous slurry to the flexible brush surface of a brush polishing machine; performing rough polishing and fine polishing on the first workpiece to be polished to obtain a target polished workpiece; collecting the splashed homogeneous slurry through a plurality of negative pressure suction nozzles below the brush disc of the brush polishing machine, and sequentially performing three-stage filtration and slurry ultrasonic regeneration treatment on the collected homogeneous slurry. Through the method, the problems of uneven polishing, high polishing cost, low efficiency and easy damage of the brittle material surface of the irregular superhard material surface can be effectively solved.

Description

Technical Field

[0001] This application relates to the field of precision machining technology for ultrahard and brittle materials, and in particular to a polishing method for irregular ultrahard material surfaces. Background Technology

[0002] In the field of superhard material processing (Mohs hardness ≥ 9, Vickers hardness > 2000 HV), precision polishing of brittle materials such as sapphire, silicon carbide, and diamond composite sheets has always been a technical challenge. Traditional processes mainly use a fixed grinding disc combined with free abrasive (such as diamond suspension), which has the following inherent defects: the fixed grinding disc + free abrasive process is difficult to conform to complex curvature or irregular surfaces, resulting in insufficient polishing uniformity, easy over-polishing or under-polishing in some areas, and low yield; low abrasive utilization rate: more than 70% of diamond micro powder is lost during polishing by splashing and cannot be recycled, resulting in high cost of abrasive per piece; significant efficiency bottleneck: due to the lack of a real-time roughness feedback mechanism, frequent machine stops are required for inspection, and polishing a single sapphire lens takes a long time; risk of surface damage: rigid polishing mechanisms are prone to generating microcracks on the surface of brittle materials, resulting in a high defect rate. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a polishing method for irregular superhard material surfaces, which can effectively solve the problems of uneven polishing, high polishing cost, low efficiency, and easy damage to brittle material surfaces.

[0004] This application provides a polishing method for irregular superhard material surfaces, comprising:

[0005] The initial workpiece to be polished is subjected to ultrasonic cleaning, rinsing and drying in sequence to obtain the first workpiece to be polished.

[0006] Refined tallow was placed in a constant temperature bath for melt treatment to obtain the target tallow.

[0007] The target tallow, 5-8 wt% of nano-alumina dispersant, and 0.1-0.3 wt% of sodium dodecylbenzenesulfonate were respectively added to a high-speed shear emulsifier and stirred to obtain an initial slurry;

[0008] The single-crystal diamond micro powder with a concentration of 15-25 vol% and the initial slurry were respectively added to a planetary mixer for uniform mixing to obtain a homogeneous slurry;

[0009] The homogeneous slurry is uniformly applied to the surface of the flexible brush on the brush disc of the brush polishing machine. The flexible brush is a spirally arranged polyimide filament with an elastic modulus of 3-5 GPa.

[0010] The first workpiece to be polished is fixed on the worktable of the brush polishing machine with its own three-dimensional adjustment fixture;

[0011] The first workpiece to be polished is subjected to rough polishing, and the surface roughness of the first workpiece to be polished is detected in real time by an online white light interferometer to obtain real-time roughness detection data. The parameters set in the rough polishing process are: brush rotation speed between 70 and 90 rpm / min, axial pressure between 400 and 500 Pa, centrifugal wheel rotation speed between 90 and 110 rpm / min, and 10 to 20 μm diamond powder is used.

[0012] When the real-time roughness detection data is less than or equal to 5nm, the process switches to fine polishing of the first workpiece to be polished to obtain the target polished workpiece. The parameters set during the fine polishing process are: brush speed between 110 and 130 rpm / min, axial pressure between 200 and 300 Pa, and 1 to 3 μm diamond powder.

[0013] During the polishing process of the first workpiece to be polished in the brush polishing machine, the splashed homogeneous slurry is collected by multiple negative pressure suction nozzles below the brush disk in the brush polishing machine, and the collected homogeneous slurry is subjected to three-stage filtration and ultrasonic regeneration treatment in sequence to obtain regenerated slurry.

[0014] According to some embodiments of this application, the step of sequentially performing ultrasonic cleaning, rinsing, and drying on the initial workpiece to be polished to obtain a first workpiece to be polished includes:

[0015] The workpiece to be polished is initially immersed in an ultrasonic cleaning tank containing clean water and detergent for 10 to 15 minutes of ultrasonic cleaning. The cleaning temperature is one of 40 to 50°C and the ultrasonic power is one of 300 to 500W.

[0016] The initial workpiece to be polished after ultrasonic cleaning is rinsed with water and placed in a clean drying oven. Hot air is introduced into the drying oven to blow away the residual liquid on the surface of the initial workpiece to be polished. The drying temperature is between 55 and 65°C and the drying time is 0.5 to 1.5 minutes to obtain the first workpiece to be polished.

[0017] According to some embodiments of this application, the temperature for melting refined tallow is one of 63 to 57°C.

[0018] According to some embodiments of this application, the step of sequentially performing three-stage filtration and ultrasonic regeneration treatment on the collected homogeneous slurry to obtain regenerated slurry includes:

[0019] The collected homogeneous slurry was sequentially passed through a primary 10μm stainless steel filter for large particle debris filtration, a secondary 1μm ceramic membrane for separating abrasive diamond aggregates, and a tertiary 0.2μm polymer filter for impurity removal, to obtain the filtered slurry.

[0020] According to some embodiments of this application, after the collected homogeneous slurry is sequentially passed through a primary 10μm stainless steel filter for large particle debris filtration, a secondary 1μm ceramic membrane for separating wear diamond aggregates, and a tertiary 0.2μm polymer filter for impurity retention, to obtain the filtered slurry, the process includes:

[0021] The filtered slurry is added to an ultrasonic regeneration tank to break up the agglomerates, and 2-3% diamond powder is added to obtain a regenerated slurry.

[0022] According to some embodiments of this application, after the first workpiece to be polished is subjected to fine polishing to obtain the target polished workpiece, the process includes:

[0023] The target polished workpiece is immersed in an ultrasonic cleaning tank containing clean water and detergent for 4 to 6 minutes to dissolve the grease on the surface of the target polished workpiece. The cleaning temperature is one of 55 to 65°C.

[0024] According to some embodiments of this application, after immersing the target polished workpiece in an ultrasonic cleaning tank containing clean water and detergent for 4-6 minutes for ultrasonic cleaning to dissolve the grease on the surface of the target polished workpiece, the process includes:

[0025] The surface roughness of the target polished workpiece is detected by a roughness testing instrument, and the surface shape accuracy of the target polished workpiece is measured by a confocal microscope to confirm whether the target polished workpiece is qualified for polishing.

[0026] According to some embodiments of this application, the step of adding single-crystal diamond micro powder with a concentration of 15-25 vol% and the initial slurry to a planetary mixer for uniform mixing to obtain a homogeneous slurry includes:

[0027] The initial slurry is added to a planetary mixer, and single-crystal diamond micro powder with a concentration of 15-25 vol% is slowly added to the planetary mixer. The single-crystal diamond micro powder and the initial slurry are uniformly mixed by the planetary mixer for 20-30 minutes to obtain a homogeneous slurry.

[0028] According to some embodiments of this application, the viscosity of the homogeneous slurry is between 1200 and 1500 cP.

[0029] The beneficial effects of this application are reflected in the following aspects: The use of spirally arranged polyimide bristles with an elastic modulus of 3-5 GPa allows for close contact with curved surfaces through micro-elastic deformation. A three-dimensional adjustment fixture dynamically adjusts the workpiece posture, ensuring full contact between the bristles and irregular surfaces. The characteristics of the tallow medium—semi-molten tallow (temperature controlled at 65±2℃)—form a viscoelastic fluid layer, uniformly transferring diamond powder to micro-depressions, eliminating stress concentration caused by traditional rigid contact, thus improving the uniformity of curved surface polishing and effectively increasing the yield. A closed-loop circulation system is employed: a negative pressure suction nozzle captures splashed slurry in real time, and the collected homogeneous slurry undergoes three-stage filtration and ultrasonic regeneration treatment to obtain regenerated slurry for recycling, reducing the cost of abrasive per piece. A white light interferometer is used to detect surface roughness (S) in real time. The system automatically switches between coarse and fine polishing stages when Sa ≤ 5nm. The slurry delivery pipeline continuously replenishes the polishing medium, avoiding downtime for material feeding, effectively shortening the polishing time per piece and increasing production capacity. Axial pressure is controlled in stages (400-500Pa for coarse polishing / 200-300Pa for fine polishing), below the sapphire fracture threshold of 600Pa. The tallow molten layer absorbs impact energy, and the SDBS synergist reduces the coefficient of friction. The single-crystal diamond micropowder has a sharper edge than traditional polycrystalline abrasives, increasing cutting force while reducing scratches, effectively lowering the microcrack incidence and surface roughness. A flexible mechanism (equipment) + tallow-based medium (material) + closed-loop control (process) constitute a complete technological ecosystem. Abrasive recycling reduces overall costs, revolutionizing the economic model of superhard material processing. This application, through this setup, effectively solves the problems of uneven polishing of irregular superhard material surfaces, high polishing costs, low efficiency, and easy damage to brittle material surfaces.

[0030] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0031] Additional aspects and advantages of this application will become apparent and readily understood in conjunction with the following description of the embodiments, in which:

[0032] Figure 1 A schematic flowchart of a polishing method for irregular superhard material surfaces provided for embodiments of this application;

[0033] Figure 2 This is a schematic diagram of the structure of the brush polishing machine provided in the embodiments of this application;

[0034] Figure 3 A schematic diagram of the process for obtaining a first workpiece to be polished, provided in an embodiment of this application;

[0035] Figure 4 This is a schematic diagram of the process for obtaining recycled slurry provided in an embodiment of this application;

[0036] Figure 5 A schematic diagram of the process for confirming whether a target polished workpiece is qualified, provided in an embodiment of this application;

[0037] Figure 6 This is a schematic diagram of the process for obtaining homogeneous slurry provided in an embodiment of this application.

[0038] Figure label:

[0039] Support base 10, mounting base 11, worktable 12, three-dimensional adjustment fixture 13, first workpiece to be polished 14, brush plate 15, temperature control nozzle 1511, first drive motor 16, slider 17, support column 18, linear guide rail 1811. Detailed Implementation

[0040] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0041] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0042] In the description of this application, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0043] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0044] In the field of superhard material processing (Mohs hardness ≥ 9, Vickers hardness > 2000 HV), precision polishing of brittle materials such as sapphire, silicon carbide, and diamond composite sheets has always been a technical challenge. Traditional processes mainly use a fixed grinding disc combined with free abrasive (such as diamond suspension), which has the following inherent defects: the fixed grinding disc + free abrasive process is difficult to conform to complex curvature or irregular surfaces, resulting in insufficient polishing uniformity, easy over-polishing or under-polishing in some areas, and low yield; low abrasive utilization rate: more than 70% of diamond micro powder is lost during polishing by splashing and cannot be recycled, resulting in high cost of abrasive per piece; significant efficiency bottleneck: due to the lack of a real-time roughness feedback mechanism, frequent machine stops are required for inspection, and polishing a single sapphire lens takes a long time; risk of surface damage: rigid polishing mechanisms are prone to generating microcracks on the surface of brittle materials, resulting in a high defect rate.

[0045] To address the aforementioned problems, this application proposes a polishing method for irregular superhard material surfaces. The embodiments of this application will be further described below with reference to the accompanying drawings.

[0046] This application provides a polishing method for irregular superhard material surfaces, referring to... Figures 1 to 2 The method includes the following steps:

[0047] Step S100: The initial workpiece to be polished is subjected to ultrasonic cleaning, rinsing and drying treatment in sequence to obtain the first workpiece to be polished 14.

[0048] It should be noted that step S100 thoroughly removes surface oil and particulate impurities to avoid contaminating the polishing slurry; drying prevents moisture from affecting the adhesion of the tallow-based polishing medium.

[0049] In this step, ultrasonic cleaning utilizes the cavitation effect to remove surface oil and particulate impurities, preventing contamination of subsequent polishing slurries; drying treatment prevents residual moisture from affecting the uniform adhesion of the tallow-based polishing medium. Execution flow: Workpiece → Ultrasonic cleaning tank (containing organic solvent) → Rinse tank (deionized water) → Hot air drying → Output "First workpiece to be polished 14".

[0050] Step S200: The refined tallow is placed in a constant temperature bath for tallow melting treatment to obtain the target tallow.

[0051] In this step, refined tallow, characterized by low impurities and high stability, is melted at a constant temperature to reach a semi-molten state, laying the rheological foundation for the preparation of homogeneous slurry. The process is as follows: refined tallow is placed in a constant temperature bath → melted to a liquid state under controlled temperature → "target tallow" is output.

[0052] In step S300, the target tallow, 5-8 wt% of nano-alumina dispersant and 0.1-0.3 wt% of sodium dodecylbenzenesulfonate are added to a high-speed shear emulsifier and stirred to obtain the initial slurry.

[0053] It should be noted that nano-alumina prevents diamond powder agglomeration, sodium dodecylbenzenesulfonate (SDBS) improves slurry wettability, and constant temperature mixing ensures that the tallow is in a semi-molten state, thus guaranteeing the suspension stability of the abrasive.

[0054] In this step, nano-alumina prevents diamond powder agglomeration due to steric hindrance; sodium dodecylbenzenesulfonate (SDBS) reduces surface tension and improves the wettability of the slurry on the workpiece / brush bristles; high-speed shear emulsification ensures uniform dispersion of additives and forms a stable suspension system. The process is as follows: target tallow + nano-alumina (5-8 wt%) + SDBS (0.1-0.3 wt%) → high-speed shear emulsifier (constant temperature environment) → stirring until homogeneous → output "initial slurry".

[0055] In step S400, single-crystal diamond micro powder with a concentration of 15-25 vol% and the initial slurry are added to a planetary mixer for uniform mixing to obtain a homogeneous slurry.

[0056] It should be noted that the planetary mixing process utilizes a combination of revolution and rotation to overcome the high viscosity of tallow, achieving agglomeration-free dispersion of diamond micron powder (15-25 vol%). The slurry is divided into two sections: one for pre-coating the brush filaments (part one) and the other for continuous supply (part two), ensuring polishing continuity. The process flow is as follows: initial slurry + single-crystal diamond micron powder → planetary mixer → uniform mixing → homogenized slurry → proportionally divided into two parts.

[0057] Working principle of planetary mixer: Revolutionary motion (the tank rotates around the main shaft): generates centrifugal force, causing the slurry to move upward along the tank wall, forming a "circulation layer" and promoting macroscopic uniformity; Rotational motion (the stirring blades inside the tank spin): the high-speed blades generate strong shear force, tearing diamond agglomerates at the micron scale.

[0058] Step S500: Apply the homogeneous slurry evenly to the flexible brush surface of the brush disk 15 in the brush polishing machine.

[0059] In this step, the flexible brush is a spirally arranged polyimide filament with an elastic modulus of 3-5 GPa.

[0060] In this step, the flexible bristle design features spirally arranged polyimide bristles (elastic modulus 3-5 GPa) that can adapt to curved surfaces and avoid local stress concentration; tallow lubrication and buffering reduce edge chipping of brittle materials; and temperature control is ensured by a PID temperature control module that maintains an environment of 65±2℃ to ensure that the tallow is in a semi-molten state, thus optimizing the rheology and lubricity of the slurry.

[0061] In some embodiments, the homogeneous slurry is divided into a first portion and a second portion. The first portion of slurry is uniformly applied to the surface of the brush of the brush polishing machine, and the second portion of slurry is supplied to the surface of the brush disk 15 of the brush polishing machine through a slurry delivery pipeline. Dual-path feeding: pre-coated bristles ensure sufficient initial contact with abrasive, and continuous supply maintains polishing stability; execution flow: first portion of slurry → manually / mechanically coated onto the brush surface, second portion of slurry → delivery pump → pipeline → surface of brush disk 15.

[0062] Step S600: Fix the first workpiece 14 to be polished onto the worktable 12 of the brush polishing machine with its own three-dimensional adjustment fixture 13.

[0063] In this step, the three-dimensional adjustment fixture 13 dynamically adjusts the workpiece's pose, compensates for surface shape errors, and ensures uniform polishing pressure. Execution flow: First workpiece to be polished 14 → fixed in the fixture → fixture installed on the polishing machine's worktable 12.

[0064] In step S700, the first workpiece 14 to be polished is rough polished, and the surface roughness of the first workpiece 14 to be polished is detected in real time by an online white light interferometer to obtain real-time roughness detection data.

[0065] In this step, the parameters set during the rough polishing process are: brush speed between 70 and 90 rpm / min, axial pressure between 400 and 500 Pa, centrifugal wheel speed between 90 and 110 rpm / min, and the use of 10-20 μm diamond powder.

[0066] In this step, large diamond particles (10–20 μm) combined with high pressure (400–500 Pa) rapidly reduce surface undulations; a white light interferometer monitors the roughness (Ra value) in real time, providing data for switching to fine polishing. Execution flow: Start the polishing machine → Set parameters (brush speed 70–90 rpm, pressure 400–500 Pa, scroll wheel 90–110 rpm) → Simultaneously monitor the Ra value online during rough polishing.

[0067] In step S800, when the real-time roughness detection data is less than or equal to 5nm, switch to fine polishing of the first workpiece 14 to be polished to obtain the target polished workpiece.

[0068] In this step, the parameters set during the fine polishing process are: brush speed between 110 and 130 rpm / min, axial pressure between 200 and 300 Pa, and the use of 1-3 μm diamond powder. In this step, small diamond particles (1-3 μm) + low pressure (200-300 Pa) eliminate microscopic defects, achieving an ultra-smooth surface (Ra≤5nm); increasing the brush speed (110-130 rpm) enhances shear force, while low pressure prevents chipping of brittle materials. Execution flow: When Ra≤5nm → switch fine polishing parameters (brush speed 110-130 rpm, pressure 200-300 Pa, change to 1-3 μm diamond powder) → polish to target precision → output "Target Polished Workpiece".

[0069] In step S900, during the polishing process of the first workpiece 14 to be polished in the brush polishing machine, the splashed homogeneous slurry is collected by multiple negative pressure suction nozzles below the brush disk 15 in the brush polishing machine, and the collected homogeneous slurry is subjected to three-stage filtration and ultrasonic regeneration treatment in sequence to obtain regenerated slurry.

[0070] It should be noted that graded filtration ensures the purity of the recovered abrasive, while ultrasonic cavitation restores the abrasive's dispersibility.

[0071] In this step, negative pressure collection: the suction nozzle below the brush disc 15 recovers splashed slurry, reducing waste; three-stage filtration: removing contaminants such as metal shavings and chipped debris in stages (e.g., 100μm → 10μm → 1μm filter screens); ultrasonic regeneration: cavitation effect deagglomerates abrasive particles, restoring dispersion stability. Execution flow: splashed slurry → negative pressure collection → three-stage filtration → ultrasonic treatment tank (power / time adjusted according to slurry state) → regenerated slurry → returned to the supply system for reuse.

[0072] This application employs spirally arranged polyimide brush filaments with an elastic modulus of 3-5 GPa. Through microscopic elastic deformation, the filaments closely conform to the curved surface. A three-dimensional adjustment fixture 13 dynamically adjusts the workpiece posture, ensuring full contact between the brush filaments and the irregular surface. The butter medium's characteristics—semi-molten butter (temperature controlled at 65±2℃)—form a viscoelastic fluid layer, uniformly transferring diamond micropowder to microscopic depressions, eliminating stress concentration caused by traditional rigid contact, thus improving the uniformity of curved surface polishing and effectively increasing the yield. A closed-loop circulation system is used: a negative pressure suction nozzle captures splashed slurry in real time, and the collected homogeneous slurry undergoes three-stage filtration and ultrasonic regeneration treatment to obtain regenerated slurry for recycling, reducing the cost of abrasive per piece. A white light interferometer is used to detect the surface roughness (Sa value) in real time. The system automatically switches between coarse and fine polishing stages when Sa ≤ 5nm. The slurry delivery pipeline continuously replenishes the polishing medium, avoiding downtime for feeding, effectively shortening the polishing time per piece and increasing production capacity. Axial pressure is controlled in stages (400-500Pa for coarse polishing / 200-300Pa for fine polishing), below the sapphire fracture threshold of 600Pa. The tallow molten layer absorbs impact energy, and the SDBS synergist reduces the coefficient of friction. The single-crystal diamond micropowder has a sharper edge than traditional polycrystalline abrasives, increasing cutting force while reducing scratches, effectively lowering the microcrack incidence and surface roughness. A flexible mechanism (equipment), tallow-based medium (material), and closed-loop control (process) constitute a complete technological ecosystem. Abrasive recycling reduces overall costs, revolutionizing the economic model of superhard material processing. This application, through this setup, effectively solves the problems of uneven polishing of irregular superhard material surfaces, high polishing costs, low efficiency, and easy damage to brittle material surfaces.

[0073] Understandably, referring to Figure 3 Step S100 includes, but is not limited to, the following steps:

[0074] Step S110: Immerse the initial workpiece to be polished into an ultrasonic cleaning tank containing clean water and detergent for ultrasonic cleaning for 10 to 15 minutes. The cleaning temperature is one of 40 to 50°C and the ultrasonic power is one of 300 to 500W.

[0075] Step S120: The initial workpiece to be polished after ultrasonic cleaning is rinsed with water and placed in a clean drying oven. Hot air is introduced into the drying oven to blow away the residual liquid on the surface of the initial workpiece to be polished. The drying temperature is between 55 and 65°C and the drying time is 0.5 to 1.5 minutes to obtain the first workpiece to be polished 14.

[0076] It should be noted that ultrasonic cleaning utilizes cavitation to generate micron-sized bubbles, which release shock waves (pressure up to 1000 atm) upon collapse on the workpiece surface, stripping away adsorbed contaminants. A water temperature of 40–50°C enhances detergent activity while preventing thermal stress cracking of brittle materials due to high temperatures. Hot air drying at 55–65°C ensures rapid drying, evaporating moisture and preventing pre-softening of the butter (butter's melting point is approximately 60°C). Deionized water rinsing prevents water residue and ensures uniform spread of the butter-based medium in subsequent steps. Its functions include: removing contaminants (removing oil and particulate impurities from the workpiece surface to prevent contamination of subsequent polishing slurries); ensuring butter adhesion (drying prevents moisture residue from affecting the uniform adhesion of the butter-based medium); and improving polishing uniformity (a clean surface ensures sufficient contact between the slurry and the material, reducing polishing defects).

[0077] It should be noted that, regarding the processing of refined tallow: the melting point of refined tallow is between 60 and 65℃, and it is kept at a constant temperature of 63 to 67℃ to maintain a liquid-solid coexistence state: the liquid phase acts as an abrasive carrier, achieving uniform dispersion; the solid phase maintains the structural strength of the slurry and prevents abrasive sedimentation; temperature control accuracy: a constant temperature bath of ±0.5℃ ensures consistent rheological properties of the tallow, laying the foundation for slurry homogenization. Its functions include: rheological regulation: converting solid tallow into a semi-molten state (liquid content >80%), reducing viscosity to a suitable mixing range (approximately 500–800 cP); stability assurance: avoiding excessively high temperatures (>70℃) that could lead to tallow oxidation or component decomposition.

[0078] It is understandable that the temperature for melting refined tallow is one of the ranges from 63 to 57°C.

[0079] Reference Figure 4 It is understood that step S900 involves sequentially performing three-stage filtration and ultrasonic regeneration on the collected homogeneous slurry to obtain regenerated slurry, including but not limited to the following steps:

[0080] In step S910, the collected homogeneous slurry is sequentially passed through a primary 10μm stainless steel filter screen for large particle debris filtration, a secondary 1μm ceramic membrane for separating abrasive diamond aggregates, and a tertiary 0.2μm polymer filter element for impurity interception, to obtain the filtered slurry.

[0081] In step S920, the filtered slurry is added to an ultrasonic regeneration tank to break up the agglomerates, and 2-3% diamond powder is added to obtain the regenerated slurry.

[0082] It should be noted that the filtered slurry is placed in an ultrasonic regeneration tank (frequency 40kHz, power 100W, duration 15 minutes) to break up the agglomerates, and then 2-3% new diamond powder is added before reuse.

[0083] It should be noted that the working principle is as follows: Staged filtration: 10μm filter screen: intercepts workpiece chipping debris and metal wear particles; 1μm ceramic membrane: separates diamond aggregates (1-5μm in size) formed by blunted edges, retaining effective single crystal particles; 0.2μm filter element: traps nanoscale impurities (such as environmental dust). Ultrasonic regeneration: 40kHz ultrasound generates cavitation bubbles in the slurry. When these bubbles collapse, the local high temperature (>5000K) and high pressure (>1000atm) destroy van der Waals forces, deagglomerating the aggregates; adding 2-3% new abrasive compensates for cutting force loss, making the regenerated slurry efficiency reach over 90% of that of new slurry.

[0084] Understandably, referring to Figure 5 After the first workpiece 14 to be polished is finely polished in step S800 to obtain the target polished workpiece, the following steps are included but not limited to:

[0085] Step S810: Immerse the target polished workpiece in an ultrasonic cleaning tank containing clean water and detergent for 4 to 6 minutes to dissolve the grease on the surface of the target polished workpiece. The cleaning temperature is one of 55 to 65°C.

[0086] It should be noted that ultrasonic cleaning is used to thoroughly remove butter residue to avoid affecting optical performance.

[0087] It should be noted that the cleaning agent is deionized water (conductivity ≤5μS / cm) to avoid metal ion contamination of the surface; the detergent is a neutral precision cleaning agent (such as ACC-100), chlorine / sulfur-free, pH: 6.5~7.5.

[0088] Understandably, referring to Figure 3 After step S810, the following steps are included, but are not limited to:

[0089] Step S820: The surface roughness of the target polished workpiece is detected by a roughness testing instrument, and the surface shape accuracy of the target polished workpiece is measured by a confocal microscope to confirm whether the target polished workpiece is qualified for polishing.

[0090] It should be noted that the surface roughness of the target polished workpiece is detected by a roughness testing instrument, and the surface accuracy of the target polished workpiece is measured by a confocal microscope. The surface roughness of the target polished workpiece is ≤0.5nm, and the surface accuracy of the target polished workpiece is ≤λ / 10.

[0091] It should be noted that the polishing quality is quantitatively verified by using a roughness testing instrument.

[0092] In this step, the working principle is as follows: Butter cleaning mechanism: 55-65℃ hot water reduces the viscosity of the butter; a neutral cleaning agent (ACC-100) emulsifies the grease molecules; ultrasonic cavitation effect thoroughly removes the residual layer; deionized water (conductivity ≤5μS / cm) prevents metal ion adsorption, ensuring surface chemical purity. Scientific basis for testing standards: Sa≤0.5nm: meets the surface requirements of high-end optical components such as laser gyroscopes and infrared windows (traditional processes Sa>1nm); PV≤λ / 10 (approximately 63nm): ensures wavefront distortion is below the diffraction limit, suitable for precision optical systems.

[0093] It should be noted that removing grease residue involves dissolving the grease medium adhering to the workpiece surface to avoid affecting optical performance; quality verification involves quantitatively evaluating the precision of the polished surface (roughness Sa, surface shape PV value) to ensure compliance with high-end application standards.

[0094] Understandably, referring to Figure 6 In step S400, single-crystal diamond powder with a concentration of 15-25 vol% and the initial slurry are added to a planetary mixer for uniform mixing to obtain a homogeneous slurry, including:

[0095] In step S410, the initial slurry is added to a planetary mixer, and single crystal diamond powder with a concentration of 15-25 vol% is slowly added to the planetary mixer. The single crystal diamond powder and the initial slurry are uniformly mixed by the planetary mixer for 20-30 minutes to obtain a homogeneous slurry.

[0096] It should be noted that the following aspects are important: Non-agglomerated dispersion: Diamond micron powder characteristics: Single-crystal diamond has high hardness and sharp edges, but is prone to agglomeration due to van der Waals forces, reducing cutting efficiency; Planetary mixing advantages: Through a combination of revolution and rotation, high-intensity shear force is generated, completely breaking up agglomerates and ensuring that each micron powder particle is independently dispersed in the tallow matrix; Precise viscosity control (1200~1500cP): Too low viscosity: Accelerated micron powder settling, stratification of the polishing slurry, leading to uneven abrasive distribution; Too high viscosity: Poor slurry flowability, affecting the stability of brush filament coating and continuous supply; Tallow base characteristics: Semi-molten tallow (65±2℃) provides a viscoelastic carrier, and the viscosity within this range can balance the suspension of micron powder and the flowability of the slurry; Process stability assurance: Concentration control (15~25vol%): Too high a concentration easily leads to micron powder collision and agglomeration; Too low a concentration results in insufficient cutting force; Slow feeding: Avoids local accumulation caused by adding micron powder all at once, ensuring gradual and uniform wetting.

[0097] Understandably, the viscosity of homogeneous slurry is between 1200 and 1500 cP.

[0098] It should be noted that, referring to Figure 2The brush polishing machine includes a support base 10, a mounting base 11, a three-dimensional adjustment fixture 13, a brush disc 15, a first drive motor 16, a second drive motor, a three-stage filtration system, a support column, and a slider 17. The mounting base 11 is disposed on one side of the support base 10. The second drive motor and the three-stage filtration system are disposed in the inner cavity of the mounting base 11. A circular groove is formed on the top of the mounting base 11 to form a worktable 12. Multiple mounting holes corresponding to negative pressure suction nozzles are provided on the top edge of the top of the mounting base 11. The negative pressure suction nozzles are mounted on the top of the mounting base 11 through the corresponding mounting holes. The output end of the negative pressure suction nozzle is connected to the input end of the three-stage filtration system. The output end of the three-stage filtration system is connected to the input end of an external ultrasonic regeneration tank. The second drive motor is a negative pressure... A motor and a three-dimensional adjustment fixture 13 are mounted on the worktable 12. A support column is mounted on the other side of the support base 10. A vertical linear guide rail 1811 is provided on the side of the support column facing the mounting base 11. A first drive motor 16 is fixedly connected to a slider 17, and the slider 17 is slidably connected to the linear guide rail 1811. A brush disk 15 is connected to the first drive motor 16 and is positioned facing the worktable 12. Multiple temperature-controlled nozzles 1511 are provided at the bottom of the brush disk 15. Each temperature-controlled nozzle 1511 is provided with multiple polyimide bristles. The polyimide bristles at the bottom of the brush disk 15 are combined to form a flexible brush. The output end of the slurry conveying pipeline is connected to the input end of the temperature-controlled nozzle 1511. The polyimide bristles at the bottom of the brush disk 15 are arranged in a spiral. The three-stage filtration system consists of a first-stage 10μm stainless steel filter screen, a second-stage 1μm ceramic membrane, and a third-stage 0.2μm polymer filter element. The spirally arranged polyimide brush filaments (elastic modulus 3-5 GPa) undergo micro-elastic deformation under pressure, tightly adhering to the irregular surface and avoiding stress concentration. The temperature-controlled nozzle 1511 maintains an environment of 65±2℃, keeping the tallow-based slurry in a semi-molten state (viscosity 1200-1500 cP), forming a viscoelastic fluid layer that evenly delivers diamond microparticles to the micro-depressions. The workpiece orientation is adjusted by the three-dimensional adjustment fixture 13 to ensure uniform polishing pressure distribution. A negative pressure suction nozzle captures splashed slurry, followed by a three-stage filtration system (10μm→1μm→0.2μm) to progressively remove debris / passivate abrasive particles. An ultrasonic regeneration tank deagglomerates the particles and adds 2-3% new diamond microparticles, returning the regenerated slurry to the supply system. An online white light interferometer monitors the surface roughness (Ra value) in real time, automatically switching between coarse and fine polishing parameters (brush speed / pressure / abrasive particle size) when Ra≤5nm.

[0099] Specifically, the workflow of the brush polishing machine is as follows: (1) Workpiece clamping and slurry preparation: Fix the first workpiece 14 to be polished on the three-dimensional adjustment fixture 13 and calibrate the normal direction of the workpiece surface; the slurry delivery pipeline continuously pumps the second part of the slurry into the temperature control nozzle 1511 at the bottom of the brush disc 15 to maintain a constant temperature of 65±2℃; the operator manually / mechanically pre-coats the first part of the slurry onto the surface of the polyimide brush bristles. (2) Coarse polishing stage: Start the equipment → Set parameters: brush speed 70~90rpm, pressure 400~500Pa, centrifugal wheel 90~110rpm → the brush disc 15 descends to contact the workpiece. Step 3: Fine polishing stage: Parameter adjustment: brush speed 110~130rpm, pressure 200~300Pa, replace 1~3μm diamond powder slurry; Continuous feeding: the temperature control nozzle 1511 continuously supplies regenerated slurry to avoid machine shutdown; End point judgment: stop polishing when the white light interferometer detects Ra≤0.5nm. (4) Slurry recycling and regeneration (simultaneous): splashed slurry → negative pressure suction nozzle → three-stage filtration system → ultrasonic regeneration tank → regenerated slurry; filtration stages: stage 1: 10μm filter screen intercepts chipped debris / metal particles, stage 2: 1μm ceramic membrane separates and passivates diamond aggregates, stage 3: 0.2μm filter element retains nano-pollutants; ultrasonic regeneration: 40kHz cavitation effect destroys van der Waals forces and deagglomerates abrasive agglomerates.

[0100] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0101] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

[0102] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A polishing method for irregular superhard material surfaces, characterized in that, include: The initial workpiece to be polished is subjected to ultrasonic cleaning, rinsing and drying in sequence to obtain the first workpiece to be polished. Refined tallow is placed in a constant temperature bath for melt treatment to obtain the target tallow. The target tallow, 5-8 wt% of nano-alumina dispersant, and 0.1-0.3 wt% of sodium dodecylbenzenesulfonate were respectively added to a high-speed shear emulsifier and stirred to obtain an initial slurry; The single-crystal diamond micro powder with a concentration of 15-25 vol% and the initial slurry were respectively added to a planetary mixer for uniform mixing to obtain a homogeneous slurry. The homogeneous slurry is uniformly applied to the surface of the flexible brush on the brush disc of the brush polishing machine. The flexible brush is a spirally arranged polyimide filament with an elastic modulus of 3-5 GPa. The first workpiece to be polished is fixed on the worktable of the brush polishing machine with its own three-dimensional adjustment fixture; The first workpiece to be polished is subjected to rough polishing, and the surface roughness of the first workpiece to be polished is detected in real time by an online white light interferometer to obtain real-time roughness detection data. The parameters set in the rough polishing process are: brush speed between 70 and 90 rpm, axial pressure between 400 and 500 Pa, centrifugal wheel speed between 90 and 110 rpm, and 10 to 20 μm diamond powder is used. When the real-time roughness detection data is less than or equal to 5nm, the process switches to fine polishing of the first workpiece to be polished to obtain the target polished workpiece. The parameters set during the fine polishing process are: brush speed between 110 and 130 rpm, axial pressure between 200 and 300 Pa, and 1 to 3 μm diamond powder. During the polishing process of the first workpiece to be polished by the brush polishing machine, the splashed homogeneous slurry is collected by multiple negative pressure suction nozzles below the brush disk in the brush polishing machine, and the collected homogeneous slurry is subjected to three-stage filtration and ultrasonic regeneration treatment in sequence to obtain regenerated slurry. The process of sequentially performing ultrasonic cleaning, rinsing, and drying on the initial workpiece to be polished to obtain the first workpiece to be polished includes: The workpiece to be polished is initially immersed in an ultrasonic cleaning tank containing clean water and detergent for 10 to 15 minutes of ultrasonic cleaning. The cleaning temperature is 40 to 50°C and the ultrasonic power is 300 to 500W. The initial workpiece to be polished after ultrasonic cleaning is rinsed with water and placed in a clean drying oven. Hot air is introduced into the drying oven to blow away the residual liquid on the surface of the initial workpiece to be polished. The drying temperature is between 55 and 65°C and the drying time is 0.5 to 1.5 minutes to obtain the first workpiece to be polished. The collected homogeneous slurry is subjected to three-stage filtration and ultrasonic regeneration treatment to obtain regenerated slurry, including: The collected homogeneous slurry was sequentially passed through a primary 10μm stainless steel filter screen for large particle debris filtration, a secondary 1μm ceramic membrane for separation of abrasive diamond aggregates, and a tertiary 0.2μm polymer filter element for impurity retention, to obtain the filtered slurry. After the collected homogeneous slurry is sequentially passed through a primary 10μm stainless steel filter for large particle debris filtration, a secondary 1μm ceramic membrane for separation of abrasive diamond aggregates, and a tertiary 0.2μm polymer filter for impurity removal, the process includes: The filter slurry is added to an ultrasonic regeneration tank to break up the agglomerates, and 2-3 vol% of single-crystal diamond powder is added to obtain a regenerated slurry. The step of adding 15-25 vol% single-crystal diamond powder and the initial slurry to a planetary mixer for uniform mixing to obtain a homogeneous slurry includes: The initial slurry is added to a planetary mixer, and single-crystal diamond micro powder with a concentration of 15-25 vol% is slowly added to the planetary mixer. The single-crystal diamond micro powder and the initial slurry are uniformly mixed by the planetary mixer for 20-30 minutes to obtain a homogeneous slurry.

2. The polishing method for irregular superhard material surfaces according to claim 1, characterized in that, The temperature for melting refined tallow is 57–63°C.

3. The polishing method for irregular superhard material surfaces according to claim 1, characterized in that, After performing fine polishing on the first workpiece to be polished to obtain the target polished workpiece, the process includes: The target polished workpiece is immersed in an ultrasonic cleaning tank containing clean water and detergent for 4 to 6 minutes to dissolve the grease on the surface of the target polished workpiece. The cleaning temperature is 55 to 65°C.

4. The polishing method for irregular superhard material surfaces according to claim 3, characterized in that, After immersing the target polished workpiece in an ultrasonic cleaning tank containing clean water and detergent for 4-6 minutes to dissolve the grease on the surface of the target polished workpiece, the process includes: The surface roughness of the target polished workpiece is detected by a roughness testing instrument, and the surface shape accuracy of the target polished workpiece is measured by a confocal microscope to confirm whether the target polished workpiece is qualified for polishing.

5. The polishing method for irregular superhard material surfaces according to claim 1, characterized in that, The viscosity of the homogeneous slurry is between 1200 and 1500 cP.

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