A polishing slurry for ultra-precision optical components in laser equipment and its preparation method

Abstract

This application proposes a polishing slurry for ultra-precision optical components in laser equipment and its preparation method, to solve the problem that the chemical corrosion rate and mechanical removal rate of polishing slurries for fused silica are difficult to precisely match, resulting in low processing efficiency or surface corrosion pits. The polishing slurry contains the following components by weight percentage: 5-15% colloidal silica, 5-12% cerium oxide, 2-8% boron carbide, 5-12% silicon carbide, 2-8% iron oxide, 3-10% potassium dichromate, 5-15% citric acid, 2-8% tartaric acid, 1-5% polyvinylpyrrolidone, 0.5-3% ammonium polyacrylate, 0.1%-1.0% surface remodeling agent, 0.5%-2.0% amino acid-based amphoteric surfactant, and 0.01%-0.1% nanodiamond, with the balance being deionized water; the surface remodeling agent is at least one of zirconium fluoride and ammonium fluorozirconate. The resulting component has a surface roughness of less than 0.1 nanometers, achieving atomic-level smoothness without scratches or pitting; subsurface microcracks are filled and repaired by a zirconium oxide layer.

Description

Technical Field

[0001] This application belongs to the field of optical component surface processing technology, specifically relating to a polishing fluid for ultra-precision optical components of laser equipment and its preparation method. Background Technology

[0002] With the continuous development of laser inertial confinement fusion, high-energy laser weapons, and photolithography technology, the performance requirements for fused silica optical glass, a core component, have reached unprecedented levels. Fused silica, due to its extremely low coefficient of thermal expansion, extremely high laser damage threshold, and excellent ultraviolet transmittance, is widely used in the manufacture of lenses, windows, and gratings in high-power laser systems. However, the increasing throughput of these systems demands that optical components not only possess extremely high surface accuracy but also atomic-level surface smoothness and extremely low subsurface defect density. Any minute surface defect or scratch can become a nucleation point for laser-induced damage, severely limiting the system's load capacity and lifespan.

[0003] In existing mechanical polishing or chemical mechanical polishing processes, a dilemma often arises when pursuing ultra-smooth surfaces. If only high-hardness abrasives (such as pure silicon carbide or diamond micron powder) are used for mechanical polishing, although the material removal rate is fast, they easily leave fine scratches (commonly known as "hairline marks") on the soft fused silica surface, leading to a decrease in surface finish. If the chemical reaction is too strong (such as using strong alkalis or hydrofluoric acid systems), although it can soften the surface, it is prone to excessive corrosion along grain boundaries or defects, forming "pitting" or hazy imperfections, damaging surface integrity. Currently, most polishing slurries for fused silica are concentrated on cerium oxide (CeO2) based slurries, whose mechanism of action mainly relies on the chemical adsorption and mechanical hydrolysis of cerium ions to remove the SiO2 network. The chemical corrosion rate and mechanical removal rate of traditional polishing slurries (such as those using only cerium oxide or iron oxide) are difficult to precisely match, resulting in low processing efficiency or the appearance of "corrosion pits" on the surface.

[0004] Traditional chemical mechanical polishing slurries are often designed for metals or compound semiconductors, and have poor compatibility with fused silica (amorphous SiO2). Existing slurries struggle to find a balance between the "peak of mechanical removal" and the "trough of chemical passivation," leading to unstable polishing processes and an inability to achieve smooth removal of materials at the molecular level. Simply mixing oxidants, abrasives, and complexing agents may result in abrasive agglomeration, oxidant deactivation, or liquid phase separation, failing to create a stable polishing environment and causing poor batch stability over polishing cycles exceeding one week. When complex polishing slurries containing multiple chemical components (such as highly oxidizing potassium dichromate and acidic complexing agents like citric acid) are introduced, prolonged immersion in strong oxidants or acidic media can cause traditional asphalt polishing molds to soften, deform, or lose their liquid-holding capacity, thereby damaging the workpiece surface.

[0005] Therefore, how to use oxidants to chemically soften the surface of optical components during polishing while ensuring a clean, residue-free, and subsurface-damaged surface after polishing is a pressing problem that needs to be solved. Summary of the Invention

[0006] In view of this, this application provides a polishing slurry for ultra-precision optical components of laser equipment and its preparation method, in order to solve the problem that the chemical corrosion rate and mechanical removal rate of the polishing slurry for fused silica are difficult to match precisely, resulting in low processing efficiency or corrosion pits on the surface.

[0007] To solve the above problems, the technical solution adopted in this application is as follows:

[0008] In a first aspect, this application proposes a polishing fluid for ultra-precision optical components of laser equipment, comprising the following components by weight percentage: 5-15% colloidal silicon oxide, 5-12% cerium oxide, 2-8% boron carbide, 5-12% silicon carbide, 2-8% iron oxide, 3-10% potassium dichromate, 5-15% citric acid, 2-8% tartaric acid, 1-5% polyvinylpyrrolidone, 0.5-3% ammonium polyacrylate, 0.1%-1.0% surface reconstruction agent, 0.5%-2.0% amino acid-type amphoteric surfactant, and 0.01%-0.1% nanodiamond, with the balance being deionized water; wherein the surface reconstruction agent is at least one of zirconium fluoride and ammonium fluorozirconate.

[0009] Preferably, the weight percentages of each component are as follows: colloidal silica 8-12%, cerium oxide 6-10%, boron carbide 4-6%, silicon carbide 6-10%, iron oxide 4-6%, potassium dichromate 5-8%, citric acid 8-12%, tartaric acid 4-6%, polyvinylpyrrolidone 1.5-3%, ammonium polyacrylate 0.8-1.5%, surface remodeling agent 0.4%-0.7%, amino acid-type amphoteric surfactant 1%-1.5%, nanodiamond 0.04%-0.07%, and the balance being deionized water.

[0010] Preferably, the polishing solution has a pH of 2.5-4.5.

[0011] Preferably, the amino acid-type amphoteric surfactant is at least one of sodium lauroyl glutamate and potassium cocoyl glycinate.

[0012] Preferably, the nanodiamond has a particle size of less than 10 nm.

[0013] Preferably, the molecular weight of the polyvinylpyrrolidone is 10,000-100,000.

[0014] Preferably, the molecular weight of the ammonium polyacrylate is 2000-5000.

[0015] Secondly, this application also proposes a method for preparing the polishing slurry for ultra-precision optical components of laser equipment as described in the first aspect, comprising the following steps: Step 1: Dissolving citric acid and tartaric acid in a first portion of deionized water and stirring until homogeneous to obtain an acidic buffer solution; Step 2: Dissolving a surface reconstruction agent in warm water at 30-50°C to obtain a pre-solution, and then adding the pre-solution to the acidic buffer solution obtained in Step 1 and mixing until homogeneous to obtain a mixed solution; Step 3: Adding potassium dichromate to the mixed solution obtained in Step 2 and stirring until completely dissolved to obtain an oxidative corrosion system; Step 4: Adding polyvinylpyrrolidone and ammonium polyacrylate to the mixture obtained in Step 3... In the oxidation corrosion system, continue stirring to obtain a dispersion system; Step 5: Disperse nanodiamonds in an aqueous solution containing ammonium polyacrylate, and ultrasonically disperse for 10-30 minutes to obtain a nanodiamond pre-dispersion; Step 6: Add colloidal silica, cerium oxide, boron carbide, silicon carbide and iron oxide sequentially to the dispersion system obtained in Step 4 while stirring, then add the nanodiamond pre-dispersion obtained in Step 5, add the remaining deionized water, and continue stirring until uniformly dispersed; Step 7: Add an amino acid-type amphoteric surfactant to the mixed system obtained in Step 6, and stir at low speed until uniformly mixed to obtain the polishing slurry for ultra-precision optical components of laser equipment.

[0016] Preferably, in step 1, the first portion of deionized water accounts for 40%-60% of the total weight of deionized water; in step 2, the weight ratio of warm water to surface reconstruction agent is 5:1-10:1.

[0017] Preferably, the stirring speed in step 6 is 800-1500 rpm, and the stirring time is not less than 40 minutes; the low-speed stirring speed in step 7 is 200-400 rpm, and the stirring time is 10-20 minutes.

[0018] Preferably, step 7 further includes a step of adjusting the pH value, using citric acid or ammonia to adjust the pH of the final polishing solution to 2.5-4.5.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of this application are:

[0020] This polishing slurry achieves ultra-precision machining of fused silica through multi-component synergy. Soft abrasives dominate chemical-mechanical removal, while hard abrasives assist in cutting peaks, and iron oxide acts as a transition layer connecting the two. Potassium dichromate and organic acids first chemically soften the surface silica layer. Cerium oxide chemically bonds and peels off the softened layer. Colloidal silica achieves atomic-level smoothing through hydration. Boron carbide and silicon carbide provide instantaneous high shear force at microscopic bumps, preventing removal blind spots caused by uneven chemical action. Iron oxide catalyzes the oxidation reaction, accelerating the softening process. This synergy achieves a chemically-dominated, mechanically-assisted removal mode, maintaining efficiency while avoiding deep scratches. After potassium dichromate oxidizes and breaks bonds, the organic acid immediately complexes dissolved silicon ions and metallic impurities to prevent redeposition. Fluoride ions in the surface reconstruction agent further etch the residual silica network. Zirconium ions react with the silanol groups on the fresh surface to form zirconium-oxygen-silicon covalent bonds, constructing a damage-resistant zirconium-oxygen layer at the atomic level. This achieves the effect of polishing and repairing simultaneously, filling subsurface microcracks and stabilizing surface chemical bonds. Polyvinylpyrrolidone (PVP) forms a basic protective film to prevent uniform corrosion. Amino acid surfactants create a localized molecular lubrication layer at the defect edges, reducing the coefficient of friction and preventing defect expansion. Nanodiamonds roll at the interface, converting sliding friction into rolling friction while rapidly dissipating frictional heat, thus protecting the defect area and reducing overall frictional heat and the risk of thermal stress damage. Ammonium polyacrylate adsorbs onto the abrasive surface, preventing agglomeration through mutual repulsion of negative charges. The long molecular chains of PPVP form a spatial barrier, further stabilizing the nanodiamonds and colloidal particles, ensuring long-term slurry stability, high batch consistency, and eliminating the risk of scratches caused by agglomerated particles.

[0021] The polishing slurry of this application produces a surface roughness of less than 0.1 nanometers for the components, achieving atomic-level smoothness without scratches or pitting; subsurface microcracks are filled and repaired by the zirconium oxide layer; the slurry shows no sedimentation after seven days of standing, extending the life of the asphalt polishing mold and reducing performance fluctuations between batches, fully meeting the extreme requirements of high-power laser systems for optical components. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0023] Figure 1 This is a flowchart illustrating the preparation process of the polishing slurry for ultra-precision optical components in laser equipment, as provided in this embodiment of the application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and do not limit the number of objects; for example, a first object can be one or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0029] Existing mechanical polishing or chemical mechanical polishing processes often face a dilemma when pursuing ultra-smooth surfaces. Using only high-hardness abrasives (such as pure silicon carbide or diamond powder) for mechanical polishing, while resulting in rapid material removal, easily leaves fine scratches (commonly known as "hairline marks") on the soft fused silica surface, leading to a decrease in surface finish. If the chemical reaction is too strong (such as using strong alkalis or hydrofluoric acid systems), although it can soften the surface, it easily causes excessive corrosion along grain boundaries or defects, forming "pitting" or hazy imperfections, damaging surface integrity. Currently, most polishing slurries for fused silica are concentrated in cerium oxide (CeO2) based slurries, whose mechanism mainly relies on the chemical adsorption and mechanical hydrolysis of cerium ions to remove the SiO2 network. The chemical corrosion rate and mechanical removal rate of traditional polishing slurries (such as those using only cerium oxide or iron oxide) are difficult to precisely match, resulting in low processing efficiency or the appearance of "corrosion pits" on the surface.

[0030] This polishing slurry achieves ultra-precision machining of fused silica through multi-component synergy. In the abrasive system, soft abrasives dominate chemical removal, while hard abrasives assist mechanical cutting. Iron oxide catalyzes the reaction, achieving a chemical-dominated, mechanically assisted removal mode that maintains efficiency while avoiding deep scratches. In the chemical system, after potassium dichromate oxidation breaks bonds, organic acids immediately complex metal ions to prevent redeposition. Zirconium fluoride reconstructs the surface through fluorine ion etching and zirconium ion bonding, achieving simultaneous polishing and repair of subsurface microcracks. At the interface control level, polyvinylpyrrolidone forms a basic passivation film to prevent uniform corrosion, amino acid surfactants target and adsorb defects to form a local lubrication layer, and nanodiamonds act as nano-balls to reduce friction and conduct heat, protecting defect areas and significantly reducing thermal stress damage. In the dispersion stabilization system, ammonium polyacrylate provides electrostatic repulsion, and polyvinylpyrrolidone contributes steric hindrance, ensuring long-term stability of the slurry without agglomeration.

[0031] The resulting benefits include: the surface roughness of the processed components is less than 0.1 nanometers, achieving atomic-level smoothness without scratches or pitting; subsurface microcracks are filled and repaired by the zirconium oxide layer; the slurry does not settle after seven days of standing, the life of the asphalt polishing mold is extended, and the performance fluctuation between batches is reduced, fully meeting the extreme requirements of high-power laser systems for optical components.

[0032] The following is in conjunction with the appendix Figure 1 The technical solutions provided in this application will be described in detail through specific embodiments and application scenarios.

[0033] In a first aspect, this application proposes a polishing fluid for ultra-precision optical components of laser equipment, comprising the following components by weight percentage: 5-15% colloidal silicon oxide, 5-12% cerium oxide, 2-8% boron carbide, 5-12% silicon carbide, 2-8% iron oxide, 3-10% potassium dichromate, 5-15% citric acid, 2-8% tartaric acid, 1-5% polyvinylpyrrolidone, 0.5-3% ammonium polyacrylate, 0.1%-1.0% surface reconstruction agent, 0.5%-2.0% amino acid-type amphoteric surfactant, and 0.01%-0.1% nanodiamond, with the balance being deionized water; wherein the surface reconstruction agent is at least one of zirconium fluoride and ammonium fluorozirconate.

[0034] In the abrasive system, colloidal silica, as a soft abrasive, has a hardness similar to fused silica. It achieves atomic-level material removal through surface hydration, primarily contributing to surface smoothness. Cerium oxide, a classic chemical abrasive, forms chemical bonds between its cerium ions and the fused silica surface, weakening the silicon-oxygen network and achieving efficient chemical-mechanical removal. Boron carbide, as a superhard abrasive, provides mechanical cutting force, primarily removing microscopic peaks and residual dense layers. Silica carbide, as a hard abrasive, assists in mechanical removal, synergistically maintaining the basic removal rate with boron carbide. Iron oxide functions as both a soft abrasive and a catalyst; its ferric ions promote the oxidation reaction of potassium dichromate and also participate in removal as an auxiliary abrasive.

[0035] In this chemical reaction system, potassium dichromate, acting as a strong oxidizing agent, oxidizes and breaks the silicon-oxygen bonds on the surface of fused silica under acidic conditions, generating soluble silicates and softening the surface layer. Citric acid, acting as the primary complexing agent and pH adjuster, provides an acidic environment, complexes metal ions, and prevents metal contamination. Tartaric acid, acting as an auxiliary complexing agent, enhances its chelating ability for polyvalent metal ions with its dihydroxyl structure and forms a pH buffer pair with citric acid, stabilizing the acidity of the system.

[0036] In terms of interface control and functional additives, polyvinylpyrrolidone (PVP) acts as a polymeric surface passivator, forming a dynamic adsorption film on the fused silica surface to physically protect microscopic low-lying areas and prevent excessive corrosion. Ammonium polyacrylate (MPA), as an anionic dispersant, prevents abrasive agglomeration through electrostatic repulsion and steric hindrance, improving slurry stability. Surface reconstruction agents provide zirconium and fluoride ions; fluoride ions etch the silica surface, while zirconium ions react with surface silanol groups to form zirconium-oxysilicon bonds, reconstructing the surface structure. Amino acid-based amphoteric surfactants, acting as defect-targeting adsorbents, exhibit an amphoteric state at different pH levels, preferentially adsorbing onto defect areas with high surface energy to form a localized lubricating layer. Nanodiamonds, acting as nano-balls and thermal conductive agents, function as rolling bearings between the abrasive and the workpiece, reducing the coefficient of friction, while their high thermal conductivity rapidly disperses interfacial heat. Deionized water, as a continuous phase solvent, carries all components, forming a stable slurry.

[0037] Multiple synergistic effects exist among the components. In the soft-hard synergistic removal mechanism of the abrasive system, soft abrasives dominate chemical-mechanical removal, hard abrasives assist in cutting peaks, and iron oxide acts as a transition layer connecting the two. Potassium dichromate and organic acids first chemically soften the surface silica, cerium oxide peels off the softened layer through chemical bonding, colloidal silica achieves atomic-level smoothing through hydration, boron carbide and silicon carbide provide instantaneous high shear force at microscopic bumps to prevent removal blind spots caused by uneven chemical action, and iron oxide catalyzes the oxidation reaction to accelerate the softening process. This synergy achieves a chemically-dominated, mechanically-assisted removal mode that maintains efficiency while avoiding deep scratches. In the oxidation-complexation-reconstruction process of the chemical system, after potassium dichromate oxidizes and breaks bonds, the organic acid immediately complexes dissolved silicon ions and metallic impurities to prevent redeposition. Fluoride ions in the surface reconstruction agent further etch the residual silica network, and zirconium ions react with the silanol groups on the fresh surface to form zirconium-oxy-silicon covalent bonds, constructing a damage-resistant zirconium-oxygen layer at the atomic level, achieving the effect of polishing and repairing simultaneously, filling subsurface microcracks, and stabilizing surface chemical bonds. During interface regulation, polyvinylpyrrolidone forms a basic protective film to prevent uniform corrosion, and amino acid surfactants form a local molecular lubrication layer at the defect edges to reduce the friction coefficient and prevent defect expansion. Nanodiamonds roll at the interface, converting sliding friction into rolling friction while rapidly dissipating frictional heat, thus protecting the defect area, reducing overall frictional heat, and minimizing the risk of thermal stress damage. In the dispersion stabilization system, ammonium polyacrylate adsorbs onto the abrasive surface, preventing agglomeration through mutual repulsion of negative charges. The long molecular chains of polyvinylpyrrolidone form a spatial barrier to further stabilize nanodiamonds and colloidal particles, ensuring long-term stability of the slurry, high batch consistency, and eliminating the risk of scratches caused by agglomerated particles.

[0038] Regarding surface quality, the polishing slurry of this application achieves several advantages. Colloidal silica and cerium oxide reduce surface roughness to below 0.1 nanometers, lowering the proportion of hard abrasive to below 20%, thus avoiding mechanical scratches. The dual protection of polymers and surfactants prevents localized over-corrosion, resulting in an atomically smooth surface free of hairline marks and corrosion pits. For subsurface damage repair, a surface reconstruction agent deposits a zirconium-oxysilicon bonded layer at the tip of subsurface cracks, repairing processing damage. Nanodiamonds provide thermal conductivity and rolling lubrication, reducing interfacial thermal stress. Regarding laser damage threshold enhancement, reduced surface defects and strong complexation of metal ions by organic acids lower surface metal residue. The enhanced laser damage resistance of the surface reconstruction layer increases the laser damage threshold. In terms of process stability, a dual stabilization mechanism prevents sedimentation after seven days of slurry settling. A pH buffer system combined with polymer protection extends the lifespan of the asphalt polishing mold. Controlled and orderly mixing in the preparation method reduces batch-to-batch performance fluctuations.

[0039] In some embodiments, the polishing solution has a pH of 2.5-4.5. In a strongly acidic environment of pH 2.5-4.5, potassium dichromate exists as dichromate ions, possessing the highest redox potential. This potential is sufficient to break the tough silicon-oxygen-silicon covalent bonds on the fused silica surface, oxidizing it into soluble silicate or silanol groups, thereby achieving efficient chemical softening of the surface. If the pH is too high, the oxidizing power of potassium dichromate decreases sharply, the chemical softening effect disappears, and the polishing process degenerates into pure mechanical grinding, leading to scratches and subsurface damage. If the pH is too low and the acidity is too strong, the oxidation reaction becomes too vigorous and uncontrollable, easily forming corrosion pits at existing minor defects. This range achieves a mild and controllable oxidation rate, ensuring uniform surface softening.

[0040] Within this pH range, the ionization equilibrium of citric acid and tartaric acid makes them highly efficient metal ion complexing agents. They can rapidly capture metal ions such as iron and chromium generated during polishing, preventing secondary deposition and metal contamination on the workpiece surface. Simultaneously, the surface reconstruction agent zirconium fluoride can stably form fluorozirconate ions at this acidity, avoiding zirconium ion hydrolysis and precipitation, while allowing fluoride ions to directionally attack silicon-oxygen bonds. The zirconium ions then undergo a bonding reaction with surface silanol groups, achieving atomic-level surface structure reconstruction.

[0041] This pH range falls precisely near the isoelectric point of amino acid-based amphoteric surfactants. Under these conditions, surfactant molecules simultaneously carry positive and negative charges, forming zwitterion pairs. This unique molecular configuration gives it an extremely high affinity for defect areas with high surface energy, allowing it to preferentially adsorb onto microscopic scratches, pits, and other similar locations, forming a localized molecular lubrication and protective film. This effectively reduces the coefficient of friction at the defects, preventing them from being mechanically amplified during polishing and achieving proactive protection of surface integrity.

[0042] At this acidity level, ammonium polyacrylate anionic dispersant can fully ionize and firmly adsorb onto the surface of various abrasive particles, providing strong electrostatic repulsion. Simultaneously, the acidic environment inhibits microbial growth and extends the shelf life of the polishing slurry.

[0043] In some embodiments, the amino acid-type amphoteric surfactant is at least one of sodium lauroyl glutamate and potassium cocoyl glycinate. Sodium lauroyl glutamate has a long-chain hydrophobic group and a dicarboxyl hydrophilic head. Within the working pH range of 2.5-4.5, its carboxyl group partially dissociates and its amino group protonates, forming a zwitterion structure. This structure gives it extremely high affinity for fused silica surfaces, especially for recognizing microscopic scratches and defect edges with high surface energy, preferentially adsorbing in these areas to form a dense molecular lubricating layer. This selective adsorption effectively reduces the coefficient of friction at defects, preventing further expansion or deepening of defects during mechanical polishing, thereby protecting surface integrity. Simultaneously, its excellent calcium soap dispersibility ensures that no precipitation forms even in hard water environments, guaranteeing the long-term stability of the polishing solution system.

[0044] Potassium cocoyl glycinate, with its glycine backbone and moderate carbon chain length, exhibits excellent wetting and penetration properties in the system. Its molecules can rapidly spread on the fused silica surface, reducing the interfacial tension between the polishing slurry and the workpiece, ensuring uniform coverage of the entire processing area and preventing scratches caused by localized dry friction. More importantly, potassium cocoyl glycinate has extremely low foaming properties, preventing the generation of numerous bubbles during high-shear polishing processes, completely eliminating potential localized pitting caused by bubble bursting. When used in combination, the two produce a significant synergistic effect. Sodium lauroyl glutamate provides strong defect-targeting adsorption and long-lasting protection, while potassium cocoyl glycinate contributes rapid wetting and anti-foaming properties; together, they construct an interfacial protective layer. This protective layer can automatically adjust its adsorption density according to the surface morphology: at the peaks of microscopic protrusions, due to strong mechanical friction, the protective film is temporarily removed, allowing chemical corrosion and mechanical removal to proceed normally; at microscopic troughs and defects, the protective film remains stable, preventing excessive corrosion and defect expansion. This adaptive mechanism is key to achieving atomically smooth, damage-free surfaces.

[0045] Furthermore, both surfactants are made from natural fatty acids and do not contain recalcitrant structures such as aromatic rings. They are easy to clean after use and do not leave organic residues on the surface of optical components, which is crucial for ensuring the cleanliness of optical components and the laser damage threshold. Compared with traditional alkyl sulfonates or quaternary ammonium salt surfactants, they have excellent compatibility with ammonium polyacrylate dispersants and polyvinylpyrrolidone passivating agents, without causing phase separation or precipitation, ensuring the stability of the entire complex formulation system.

[0046] In some embodiments, the nanodiamonds have a particle size of less than 10 nm. The polyvinylpyrrolidone has a molecular weight of 10,000-100,000. The ammonium polyacrylate has a molecular weight of 2,000-5,000.

[0047] When the particle size of nanodiamond is less than 10 nanometers, its size is much smaller than the gap between the polishing pad and the workpiece, and also much smaller than the particle size of other micron- or submicron-sized abrasives in the polishing slurry. This allows the nanodiamond to roll freely between the abrasive particles and the workpiece surface, as well as between the abrasive and the polishing pad, forming a veritable nanobearing. This transforms sliding friction into rolling friction, significantly reducing the overall coefficient of friction. This nanobearing effect effectively reduces the generation of frictional heat, while its extremely high specific surface area and surface activity allow it to quickly absorb and dissipate local hotspot heat, preventing microcracks from forming on the fused silica surface due to thermal stress. Furthermore, the tiny size ensures that the nanodiamond itself will not become a new source of scratches. Even if a small amount of agglomerates, it can be redispersed under the action of a dispersant, thus providing lubrication and heat conduction while ensuring that the component surface is not mechanically damaged.

[0048] The molecular weight of the polyvinylpyrrolidone (PVP) is preferably between 10,000 and 100,000. PPVPs within this molecular weight range have a suitable chain length, allowing them to adhere firmly to the fused silica surface and abrasive particles through multi-point adsorption, forming a stable steric hindrance layer, without causing excessively long molecular chains that result in excessively high viscosity of the polishing fluid or difficult-to-clean residues. On the fused silica surface, it forms a dynamically reversible adsorption film. At the microscopic peaks, it is temporarily removed due to mechanical friction, allowing for normal chemimechanical removal; at microscopic valleys and defects, it remains stable, effectively preventing excessive erosion of the surface by corrosive chemical components, achieving selective protection by passivating valleys and exposing peaks. On the abrasive particle surface, it synergistically enhances dispersion stability with ammonium polyacrylate through steric hindrance, preventing particle agglomeration. Simultaneously, PPVPs within this molecular weight range have good water solubility and film-forming properties, making them easy to clean after polishing and leaving no organic contaminants on the optical component surface.

[0049] Ammonium polyacrylate with a molecular weight of 2000 to 5000 possesses high charge density and moderate molecular size, enabling it to rapidly adsorb onto the surface of various abrasive particles. Its negative charge generated by ionization provides strong electrostatic repulsion, effectively preventing the aggregation and sedimentation of colloidal silica, cerium oxide, boron carbide, and other particles. Compared to dispersants with higher molecular weights, this range of ammonium polyacrylate does not cause excessive thickening or flocculation of the slurry, ensuring good flowability and mass transfer properties in the polishing fluid. Simultaneously, its relatively short molecular chain reduces its sensitivity to pH changes and electrolyte concentrations, maintaining stable dispersion within an acidic pH range of 2.5 to 4.5. Furthermore, this low molecular weight ammonium polyacrylate is more easily desorbed from the workpiece surface during the post-polishing cleaning process, avoiding the potential impact of dispersant residue on the cleanliness of optical components and the laser damage threshold.

[0050] There is also a close synergistic relationship among these three preferred parameters. Nanodiamonds smaller than 10 nanometers require an effective dispersion system to function as nanobearings and conduct heat, and ammonium polyacrylate with a molecular weight of 2000 to 5000 provides this efficient and stable dispersion guarantee, preventing nanodiamond agglomeration and failure. Polyvinylpyrrolidone with a molecular weight of 10000 to 100000 constructs a protective layer on the fused silica surface, complementing the rolling lubrication of the nanodiamonds. The former provides chemical passivation protection, while the latter provides physical lubrication and cooling, together constructing a complete interface control system. These three components, working synergistically with other components in the polishing fluid, ultimately achieve comprehensive and precise control over the mechanical, chemical, and thermal effects on the fused silica surface.

[0051] Secondly, this application also proposes a method for preparing the polishing slurry for ultra-precision optical components of laser equipment as described in the first aspect, comprising the following steps: Step 1: Dissolving citric acid and tartaric acid in a first portion of deionized water and stirring until homogeneous to obtain an acidic buffer solution; Step 2: Dissolving a surface reconstruction agent in warm water at 30-50°C to obtain a pre-solution, and then adding the pre-solution to the acidic buffer solution obtained in Step 1 and mixing until homogeneous to obtain a mixed solution; Step 3: Adding potassium dichromate to the mixed solution obtained in Step 2 and stirring until completely dissolved to obtain an oxidative corrosion system; Step 4: Adding polyvinylpyrrolidone and ammonium polyacrylate to the mixture obtained in Step 3... In the oxidation corrosion system, continue stirring to obtain a dispersion system; Step 5: Disperse nanodiamonds in an aqueous solution containing ammonium polyacrylate, and ultrasonically disperse for 10-30 minutes to obtain a nanodiamond pre-dispersion; Step 6: Add colloidal silica, cerium oxide, boron carbide, silicon carbide and iron oxide sequentially to the dispersion system obtained in Step 4 while stirring, then add the nanodiamond pre-dispersion obtained in Step 5, add the remaining deionized water, and continue stirring until uniformly dispersed; Step 7: Add an amino acid-type amphoteric surfactant to the mixed system obtained in Step 6, and stir at low speed until uniformly mixed to obtain the polishing slurry for ultra-precision optical components of laser equipment.

[0052] In step 1, citric acid and tartaric acid are pre-dissolved in deionized water to construct a stable acidic buffer solution system. This provides a suitable acidic environment for all subsequently added components, preventing potential runaway chemical reactions or component hydrolysis caused by local pH fluctuations. The dual complex effect of citric acid and tartaric acid is initially formed in this step, laying the foundation for subsequent efficient complexation of metal ions.

[0053] Step 2 involves dissolving the surface reconstruction agent in warm water at 30-50°C to obtain a pre-solution, which is then added to an acidic buffer solution. Because zirconium fluoride or ammonium fluorozirconate dissolves slowly and is easily hydrolyzed in room temperature water, warm water dissolution ensures complete dissolution and its presence in the form of active ions. Preparing the pre-solution before mixing avoids potential localized supersaturation or hydrolytic precipitation that may occur when the solid surface reconstruction agent is directly added to the acidic system. This ensures that zirconium and fluoride ions are uniformly and stably distributed throughout the system, providing a homogeneous source of activity for the subsequent surface reconstruction reaction.

[0054] Step 3: Add potassium dichromate to the mixed solution and stir until completely dissolved. In the presence of the established acidic buffer system and surface remodeling agent, potassium dichromate can disperse rapidly and uniformly, achieving maximum oxidative activity. This step ensures that the strong oxidant and acidic medium are fully integrated, forming a uniform oxidative corrosion system, which guarantees the subsequent uniform softening of the fused silica surface. If the order of addition is reversed or dissolution is insufficient, uneven local oxidative forces may occur, leading to uneven corrosion.

[0055] Step 4 involves adding polyvinylpyrrolidone (PVP) and ammonium polyacrylate (MPA) to the oxidative corrosion system. These two polymers, in the established acidic oxidative environment, can fully extend their molecular chains, exerting a dual stabilizing effect of steric hindrance and electrostatic repulsion. They not only begin to adsorb onto any small particles that may be present in the solution but also construct a preliminary dispersion and protection network for the large amount of abrasive to be added. This step ensures that the polymeric dispersant and passivator are fully dissolved and activated before the abrasive is added, enabling them to encapsulate and stabilize the newly added particles immediately.

[0056] Step 5 involves dispersing nanodiamonds in an aqueous solution containing ammonium polyacrylate and then ultrasonically dispersing them. Nanodiamonds have extremely small particle sizes, huge specific surface areas, and extremely high surface energy, making them highly prone to aggregation. Using a solution containing ammonium polyacrylate as the dispersion medium, supplemented by ultrasonic energy, effectively breaks up the aggregates, allowing ammonium polyacrylate molecules to rapidly adsorb onto the surface of each nanodiamond particle, forming a stable charged protective layer. This pre-dispersion treatment is a prerequisite for nanodiamonds to exert their nanobearing and thermal conductivity functions. If nanodiamond powder is directly added to the main system, it will almost inevitably lead to aggregation and may even become a new source of scratches.

[0057] Step 6 involves sequentially adding colloidal silica, cerium oxide, boron carbide, silicon carbide, and iron oxide to the dispersion system, followed by the addition of nanodiamond pre-dispersion and deionized water. This order of addition follows the principle of starting with easily dispersed materials and progressing to less dispersed materials, and from large quantities to small quantities. The colloidal silica, as a soft abrasive already in a dispersed state, is added first, contributing to the establishment of a stable system. The subsequent addition of various abrasive materials is promptly encapsulated within the existing polymer protective network, preventing agglomeration. Finally, the fully pre-dispersed nanodiamond is added, ensuring that this key functional component enters the final product in the most ideal dispersion state. Continuous stirring until uniform dispersion is achieved ensures that all solid components are completely and uniformly distributed in the liquid phase.

[0058] Step 7 involves adding the amino acid-based amphoteric surfactant in the final stage and stirring at a low speed. Surfactants tend to generate a large amount of foam under high shear forces, and low-speed stirring effectively avoids foam formation. Adding it last prevents it from degrading or becoming inactive due to shearing during prolonged, high-intensity stirring, while also ensuring that it can fully utilize its interfacial adsorption and defect targeting functions after all other components have been evenly distributed, without interfering with the abrasive dispersion process.

[0059] In summary, this preparation method, through meticulous operations such as stepwise dissolution, pre-dispersion treatment, ordered mixing, and low-speed finishing, successfully solves a series of process challenges in complex multi-component systems, including easy agglomeration, hydrolysis, deactivation, and foaming. The resulting polishing slurry exhibits extremely high batch stability, excellent dispersion uniformity, and long-term storage stability, ensuring that every drop of polishing slurry can exert the designed synergistic effect during processing. This provides a reliable process guarantee for the stable acquisition of atomically smooth, damage-free fused silica optical components with high laser damage thresholds.

[0060] Specifically, in step 1, the first portion of deionized water constitutes 40%-60% of the total weight of deionized water. If the amount of water in the first portion is too low, citric acid and tartaric acid will be difficult to dissolve fully in the limited solvent, potentially leading to localized supersaturation or even crystallization, affecting the homogeneity of the buffer system. If the amount of water in the first portion is too high, there will be insufficient remaining water when adding other components in subsequent steps, making it difficult to precisely control the solid content by adjusting the final amount of water added. A range of 40% to 60% ensures that the acidic buffer solution has a suitable concentration and volume, guaranteeing both the complete ionization and uniform dispersion of the organic acids, while also providing sufficient adjustment space for the addition and mixing of subsequent steps.

[0061] The preferred weight ratio of warm water to surface reconstruction agent in step 2 is 5:1 to 10:1. This range ensures complete dissolution and stable activity of the surface reconstruction agent. If the liquid-to-solid ratio is too low, the surface reconstruction agent will not dissolve fully in the warm water, and undissolved solid particles may remain. These particles, when added to the main system later, will not only fail to perform their surface reconstruction function but may also become new sources of contamination or scratches. If the liquid-to-solid ratio is too high, the pre-solution volume will be too large, potentially diluting the concentration of other components in the main system and affecting the accuracy of the final formulation. A liquid-to-solid ratio of 5:1 to 10:1 ensures that the surface reconstruction agent is completely dissolved and forms a stable active ionic state while controlling the pre-solution volume within a reasonable range, allowing it to be smoothly integrated into the main system without disrupting the overall formulation balance.

[0062] Furthermore, the stirring speed in step 6 is preferably 800 to 1500 rpm, and the stirring time is no less than 40 minutes. Stirring speeds below 800 rpm are insufficient to provide enough shear force to break up any soft agglomerates that may exist between abrasive particles, especially for high-density, easily settling hard abrasives such as boron carbide and silicon carbide. Low-speed stirring may cause them to deposit at the bottom of the container, failing to achieve uniform dispersion. On the other hand, excessively high speeds exceeding 1500 rpm may introduce a large number of air bubbles and cause the polymer chains of polyvinylpyrrolidone and other high-molecular-weight materials to break due to excessive shearing, thus compromising their passivation and stabilization functions. A stirring time of no less than 40 minutes ensures that all abrasive components, from colloidal silica to iron oxide, are gradually and uniformly dispersed under the protection of the polymer dispersion network, achieving complete dynamic equilibrium between the solid and liquid phases, ultimately forming a homogeneous and stable slurry system.

[0063] Furthermore, the preferred low-speed stirring rate in step 7 is 200 to 400 rpm, and the stirring time is 10 to 20 minutes. This mild mixing condition is specifically designed for the characteristics of amino acid-based amphoteric surfactants. These surfactants have a significant foaming tendency. If the same high-speed stirring as in step 6 is used, a large amount of stable foam will be generated rapidly. This foam not only occupies the effective volume and affects the mixing uniformity, but more seriously, the bubbles may adhere to the workpiece surface during subsequent polishing, causing localized pitting when they burst. The low-speed stirring of 200 to 400 rpm provides sufficient hybrid mixing while keeping air entrainment and foam generation to a minimum. A stirring time of 10 to 20 minutes is sufficient for surfactant molecules to be uniformly adsorbed at the solid-liquid interface and reach adsorption equilibrium. A longer stirring time is unnecessary and may destroy the formed adsorption structure due to continuous shearing.

[0064] Step 7 also includes adjusting the pH of the final polishing solution to 2.5 to 4.5 using citric acid or ammonia. This fine-tuning has several beneficial effects. First, using citric acid or ammonia as a pH adjuster is completely consistent with the components already present in the formulation, ensuring the chemical purity of the polishing solution by avoiding the introduction of any foreign impurity ions. Second, after all the aforementioned feeding and mixing steps, the pH of the system may experience slight shifts due to batch differences in raw materials or fluctuations in water purity. This final adjustment step precisely corrects for these shifts, ensuring that the pH of each batch of product is strictly locked within the optimal working window of 2.5 to 4.5. Third, placing pH adjustment in the final step avoids potential component hydrolysis or stability degradation caused by acidity changes during subsequent prolonged stirring, ensuring the final product is in its most stable chemical state.

[0065] Example 1

[0066] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 35.25% (352.5 g). Among them, polyvinylpyrrolidone with a molecular weight of 50,000, ammonium polyacrylate with a molecular weight of 3,500, and nanodiamond with a particle size of 5 to 8 nanometers are selected.

[0067] During the preparation stage, accurately weigh all raw materials according to the above proportions. Divide the total amount of deionized water (352.5 g) into three parts for later use: the first part is used for step 1, the second part is used for the warm water in step 2, and the third part is used for supplementary water in steps 5 and 6.

[0068] Step 1: Prepare an acidic buffer solution. Weigh 100.0 g of citric acid and 50.0 g of tartaric acid, and add them to the first portion of deionized water, which is 50% of the total weight of the deionized water, i.e., 176.0 g. Stir at 300 rpm for 15 minutes at room temperature until the solids are completely dissolved, resulting in a colorless and transparent acidic buffer solution.

[0069] Step 2 involves pre-dissolving the surface reconstruction agent. Weigh 5.0 g of zirconium fluoride. Measure 40.0 g of 40°C warm water (8:1 weight ratio of water to surface reconstruction agent), place it in a beaker, and slowly add the zirconium fluoride to the warm water while stirring at 200 rpm for 5 minutes until completely dissolved, obtaining a clear zirconium fluoride pre-solution. Slowly pour this pre-solution into the acidic buffer solution from Step 1, stirring at 400 rpm while adding. After the addition is complete, continue stirring for 10 minutes to ensure homogeneous mixing, obtaining a mixed solution.

[0070] Step 3: Add oxidant. Weigh 65.0 g of potassium dichromate and slowly add it to the mixed solution obtained in Step 2. Control the addition rate to prevent excessively high local concentrations. Stir at 500 rpm for 15 minutes until the potassium dichromate is completely dissolved and the solution is orange-red and transparent, thus obtaining the oxidative corrosion system.

[0071] Step 4: Add polymeric dispersant and passivating agent. Weigh 30.0 g of polyvinylpyrrolidone and 15.0 g of ammonium polyacrylate, and add them sequentially to the oxidative corrosion system from Step 3. Stir at 600 rpm for 20 minutes to ensure the polymer is fully dissolved and uniformly dispersed, resulting in a dispersion system with a certain viscosity.

[0072] Step 5 involves pre-dispersing the nanodiamonds. Weigh 0.5 g of nanodiamonds. Separately, take approximately 20.0 g of deionized water and add 0.1 g of ammonium polyacrylate (reserved from the total amount weighed in Step 4). Stir to dissolve and obtain a dilute dispersant solution. Add the nanodiamonds to this solution, first manually stirring to wet the particles, then placing it in an ultrasonic disperser and ultrasonically dispersing at 40 kHz for 20 minutes to obtain a uniform and stable nanodiamond pre-dispersion with no obvious particle agglomeration.

[0073] Step 6: Add the abrasive system. Transfer the dispersion obtained in Step 4 to a mixing container and turn on the stirrer, setting the speed to 1200 rpm. Add the various abrasives in the following order: first, slowly add 100.0 g of colloidal silica and stir for 5 minutes; then add 85.0 g of cerium oxide and stir for 5 minutes; next, add 50.0 g of boron carbide and stir for 8 minutes; then add 85.0 g of silicon carbide and stir for 8 minutes; finally, add 50.0 g of iron oxide and stir for 10 minutes. Observe the slurry state during the addition process to ensure there is no clumping or climbing. After all the abrasives have been added, add the entire nanodiamond pre-dispersion prepared in Step 5 to the system. Then add the remaining deionized water. The total deionized water is 352.5 g. Subtract the 176.0 g used in Step 1, 40.0 g used in Step 2, and 20.0 g used in Step 5, leaving 116.5 g. Continue stirring at 1200 rpm for 50 minutes to ensure the system is fully and uniformly dispersed.

[0074] Step 7: Add surfactant and adjust pH, reducing the stirring speed to 300 rpm. Weigh 12.0 g of sodium lauroyl glutamate and slowly add it to the mixture from Step 6, maintaining low-speed stirring for 15 minutes to ensure uniform dispersion of the surfactant and avoid foaming. After stirring, take a sample to measure the pH value of the polishing solution using a precision pH meter. In this example, the measured pH was 3.2, which is within the target range of 2.5 to 4.5 and requires no adjustment.

[0075] The post-processing step involves filtering the prepared polishing slurry through a 200-mesh stainless steel filter to remove any small amounts of foreign matter or undispersed particles. The filtered polishing slurry is then placed in a clean polyethylene plastic container, sealed, and stored to obtain the final product.

[0076] The polishing slurry prepared in this embodiment is a uniform and stable suspension, orange-red in color, with no obvious precipitation, a pH of 3.2, moderate viscosity, and good fluidity. After standing for 7 days, no stratification or hard sedimentation was observed. When applied to polishing fused silica optical components, the following effects can be achieved: surface roughness Ra is less than 0.1 nanometers, with no scratches or pitting; the subsurface damage layer depth is less than 10 nanometers; and the material removal rate is stable at 0.8 to 1.2 micrometers per hour, meeting the efficiency requirements of ultra-precision machining.

[0077] Example 2

[0078] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component added is as follows: colloidal silicon dioxide 8.0% (80.0 g), cerium oxide 8.5% (85.0 g), boron carbide 6.0% (60.0 g), silicon carbide 9.5% (95.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 35.25% (352.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0079] Example 3

[0080] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component fed is as follows: colloidal silicon dioxide 12.0% (120.0 g), cerium oxide 8.5% (85.0 g), boron carbide 4.0% (40.0 g), silicon carbide 7.5% (75.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 35.25% (352.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0081] Example 4

[0082] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 1.5% (15.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 36.75% (367.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0083] Example 5

[0084] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 2.25% (22.5 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 36% (360 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0085] Example 6

[0086] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.2% (12.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 35.55% (355.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0087] Example 7

[0088] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 0.8% (8.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 35.95% (359.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0089] Example 8

[0090] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.4% (4.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 35.35% (353.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0091] Example 9

[0092] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.7% (7.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 35.05% (350.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0093] Example 10

[0094] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1% (10.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 35.45% (354.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0095] Example 11

[0096] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.5% (15.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.05% (0.5 g), and deionized water 34.95% (349.5 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0097] Example 12

[0098] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.04% (0.4 g), and deionized water 35.26% (352.6 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0099] Example 13

[0100] In this embodiment, the weight percentages of each component are selected as follows. Taking a total preparation amount of 1000 g as an example, the actual amount of each component is as follows: colloidal silicon dioxide 10.0% (100.0 g), cerium oxide 8.5% (85.0 g), boron carbide 5.0% (50.0 g), silicon carbide 8.5% (85.0 g), iron oxide 5.0% (50.0 g), potassium dichromate 6.5% (65.0 g), citric acid 10.0% (100.0 g), tartaric acid 5.0% (50.0 g), polyvinylpyrrolidone 3.0% (30.0 g), ammonium polyacrylate 1.5% (15.0 g), zirconium fluoride 0.5% (5.0 g) as the surface reconstruction agent, sodium lauroyl glutamate 1.2% (12.0 g) as the amino acid-type amphoteric surfactant, nanodiamond 0.07% (0.7 g), and deionized water 35.23% (352.3 g). The polyvinylpyrrolidone used has a molecular weight of 50,000, the ammonium polyacrylate has a molecular weight of 3,500, and the nanodiamond particles have a size of 5 to 8 nanometers. The preparation method is the same as in Example 1.

[0101] Comparative Example 1

[0102] The only difference between this comparative example and Example 1 is that colloidal silicon dioxide is not added, the amount of boron carbide added is increased by 5.0% (total 100.0 g), and the amount of silicon carbide added is increased by 5.0% (total 135 g).

[0103] Comparative Example 2

[0104] The only difference between this comparative example and Example 1 is that polyvinylpyrrolidone is not added, and the variation is adjusted by deionized water.

[0105] Comparative Example 3

[0106] The only difference between this comparative example and Example 1 is that ammonium polyacrylate is not added, and the variation is adjusted by deionized water.

[0107] Comparative Example 4

[0108] The only difference between this comparative example and Example 1 is that no surface reconstruction agent is added, and the amount of change is adjusted by deionized water.

[0109] Comparative Example 5

[0110] The only difference between this comparative example and Example 1 is that no amino acid-type amphoteric surfactant is added, and the variation is adjusted by deionized water.

[0111] Comparative Example 6

[0112] The only difference between this comparative example and Example 1 is that no nanodiamonds are added, and the variation is adjusted by deionized water.

[0113] The relevant data of the above embodiments and comparative examples are shown in Table 1.

[0114] Table 1. Relevant data for examples and comparative examples

[0115]

[0116] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0117] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0118] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0119] Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

Claims

1. A polishing slurry for ultra-precision optical components in laser equipment, characterized in that, The product comprises the following components by weight percentage: 5-15% colloidal silica, 5-12% cerium oxide, 2-8% boron carbide, 5-12% silicon carbide, 2-8% iron oxide, 3-10% potassium dichromate, 5-15% citric acid, 2-8% tartaric acid, 1-5% polyvinylpyrrolidone, 0.5-3% ammonium polyacrylate, 0.1%-1.0% surface remodeling agent, 0.5%-2.0% amino acid-type amphoteric surfactant, and 0.01%-0.1% nanodiamond, with the balance being deionized water; the surface remodeling agent is at least one of zirconium fluoride and ammonium fluorozirconate.

2. The polishing slurry for ultra-precision optical components in laser equipment according to claim 1, characterized in that, The weight percentages of each component are as follows: colloidal silica 8-12%, cerium oxide 6-10%, boron carbide 4-6%, silicon carbide 6-10%, iron oxide 4-6%, potassium dichromate 5-8%, citric acid 8-12%, tartaric acid 4-6%, polyvinylpyrrolidone 1.5-3%, ammonium polyacrylate 0.8-1.5%, surface remodeling agent 0.4%-0.7%, amino acid-type amphoteric surfactant 1%-1.5%, nanodiamond 0.04%-0.07%, and the balance being deionized water.

3. The polishing slurry for ultra-precision optical components in laser equipment according to claim 1, characterized in that, The polishing solution has a pH of 2.5-4.

5.

4. The polishing slurry for ultra-precision optical components in laser equipment according to claim 1, characterized in that, The amino acid-type amphoteric surfactant is at least one of sodium lauroyl glutamate and potassium cocoyl glycinate.

5. The polishing slurry for ultra-precision optical components in laser equipment according to claim 1, characterized in that, The nanodiamonds have a particle size of less than 10 nm.

6. The polishing slurry for ultra-precision optical components in laser equipment according to claim 1, characterized in that, The molecular weight of the polyvinylpyrrolidone is 10,000-100,000; And / or, the molecular weight of the ammonium polyacrylate is 2000-5000.

7. A method for preparing a polishing slurry for ultra-precision optical components of laser equipment as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Step 1: Dissolve citric acid and tartaric acid in the first part of deionized water, stir well, and obtain an acidic buffer solution; Step 2: Dissolve the surface reconstruction agent in warm water at 30-50℃ to obtain a pre-solution, and then add the pre-solution to the acidic buffer solution obtained in Step 1, and mix well to obtain a mixed solution; Step 3: Add potassium dichromate to the mixed solution obtained in Step 2 and stir until completely dissolved to obtain an oxidative corrosion system; Step 4: Add polyvinylpyrrolidone and ammonium polyacrylate to the oxidative corrosion system obtained in Step 3, and continue stirring to obtain a dispersion system; Step 5: Disperse the nanodiamonds in an aqueous solution containing ammonium polyacrylate and ultrasonically disperse for 10-30 minutes to obtain a nanodiamond pre-dispersion. Step 6: Add colloidal silica, cerium oxide, boron carbide, silicon carbide and iron oxide sequentially to the dispersion system obtained in step 4 while stirring. Then add the nanodiamond pre-dispersion obtained in step 5, add the remaining deionized water, and continue stirring until uniformly dispersed. Step 7: Add the amino acid-type amphoteric surfactant to the mixture obtained in Step 6, and stir at low speed until the mixture is uniform to obtain the polishing slurry for ultra-precision optical components of laser equipment.

8. The preparation method according to claim 7, characterized in that, In step 1, the first portion of deionized water accounts for 40%-60% of the total weight of deionized water; in step 2, the weight ratio of warm water to surface reconstruction agent is 5:1-10:

1.

9. The preparation method according to claim 7, characterized in that, In step 6, the stirring speed is 800-1500 rpm and the stirring time is no less than 40 minutes; in step 7, the low-speed stirring speed is 200-400 rpm and the stirring time is 10-20 minutes.

10. The preparation method according to claim 7, characterized in that, Step 7 also includes adjusting the pH value by using citric acid or ammonia to adjust the pH of the final polishing solution to 2.5-4.5.

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