CN110295011B - Polishing solution for KDP crystal and preparation method and application thereof - Google Patents
Polishing solution for KDP crystal and preparation method and application thereof Download PDFInfo
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- CN110295011B CN110295011B CN201910645289.5A CN201910645289A CN110295011B CN 110295011 B CN110295011 B CN 110295011B CN 201910645289 A CN201910645289 A CN 201910645289A CN 110295011 B CN110295011 B CN 110295011B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B57/00—Devices for feeding, applying, grading or recovering grinding, polishing or lapping agents
- B24B57/02—Devices for feeding, applying, grading or recovering grinding, polishing or lapping agents for feeding of fluid, sprayed, pulverised, or liquefied grinding, polishing or lapping agents
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09G—POLISHING COMPOSITIONS; SKI WAXES
- C09G1/00—Polishing compositions
- C09G1/04—Aqueous dispersions
Abstract
The invention discloses polishing solution for KDP crystals, a preparation method and application thereof, wherein the polishing solution comprises the following components in percentage by volume: polar phase: 1-10%; non-polar phase: 30% -55%; the balance being the two solvent phase. The polishing solution disclosed by the invention is simple in preparation method and stable in property, the fly-cutting knife lines can be effectively removed under a lower polishing pressure (1-2.5 kPa), the problems of subsurface damage and the like possibly caused by a higher polishing pressure are avoided, and the surface roughness after polishing is improved to a certain extent. The polishing solution is a common organic reagent and does not react with KDP chemically, the polishing solution does not use an amphiphilic surfactant, and after polishing, surface cleaning can be realized by simply washing the surface by adopting one of the components (double solvent phases) of the polishing solution, and no impurity residue is generated on the surface.
Description
Technical Field
The invention relates to the technical field of ultra-precision machining microemulsion polishing solution, in particular to polishing solution for KDP crystals and a preparation method and application thereof.
Background
The potassium dihydrogen phosphate (KDP) crystal is a very good nonlinear optical element, and is the only nonlinear optical material which can be used for laser frequency doubling, electro-optical modulation and photoelectric switching devices of optical path systems such as ICF and intense laser weapons at present. The surface quality of KDP crystal in engineering application is extremely high, such as ultra-smooth, no surface defect, no stress residue and no impurity residue, and is close to the limit of material processing. However, the KDP crystal material has the characteristics of softness, brittleness, deliquescence, sensitivity to temperature change, anisotropy and the like, so that the KDP crystal has extremely strong challenge in processing. At present, a single-point diamond fly-cutting (SPDT) technology is the only KDP crystal ultra-precision machining technology which can meet the requirements of engineering application, and units such as national LLNL laboratories and Harbin industry university in China have obtained some achievements in the field. Although the SPDT technology can obtain lower surface roughness, periodic small scale ripples (fly-cutter ripples) and subsurface damage are generated on the crystal surface, and damage are easily generated under the action of high-power laser. Therefore, the research on the surface post-treatment technology of the KDP crystal after the fly-cutting has important research value and application prospect.
Chemical mechanical polishing is a surface polishing technique that is well established in the semiconductor industry, can achieve planarization of a workpiece over the full size range, and has technical advantages in preparing ultra-smooth surfaces. In the chemical mechanical polishing, the polishing solution is one of the core of the whole technical process, the physical and chemical properties of the polishing solution directly affect the precision level of the chemical mechanical polishing, and if the traditional polishing solution is selected, the surface of the KDP crystal can be atomized or damaged. Therefore, the design of the special polishing solution suitable for the soft, crisp and deliquescent crystals is the basis for developing the chemical mechanical polishing of the KDP crystals.
Disclosure of Invention
The invention aims to provide a polishing solution for KDP crystals, which can realize the deliquescence and polishing effect of the traditional water-in-oil microemulsion, and can effectively avoid surface aggravation deliquescence and secondary pollution caused by surfactant residues after polishing because of no surfactant.
In addition, the invention also relates to a preparation method and application of the polishing solution.
The invention is realized by the following technical scheme:
a polishing solution for KDP crystals, which consists of the following components in percentage by volume:
polar phase: 1-10%;
non-polar phase: 30% -55%;
the balance being the two solvent phase.
The patent of 'a non-water-based abrasive-free polishing solution for soft, brittle and deliquescent crystals' disclosed in Chinese patent document library is CN00910010268.2, alcohol or ester is selected as an oil phase, a high-carbon fatty alcohol polyoxyethylene ether and other nonionic surfactants are selected as surface active substances, a water-in-oil microemulsion is prepared, and the removal of the crystal surface is realized through the friction action between a polishing pad and crystals during polishing.
The research of the applicant finds that the water-in-oil microemulsion containing the surfactant is used as the polishing solution, the surfactant is easy to adhere to the surface of the crystal after polishing, the cleaning is difficult, and due to the amphipathy of the surfactant, the deliquescence of the KDP surface is further accelerated, and the surface quality is deteriorated.
Therefore, the applicant conducted experimental studies on the components of the polishing solution and redesigned the formulation of the polishing solution without the surfactant, and found through long-term experiments that:
specific polar phase, non-polar phase and double solvent phase are combined according to a certain proportion to form a monodispersion system similar to water-in-oil microemulsion. The water in the polishing solution can still exist in the form of nano-scale liquid drops, and because the traditional surfactant is not suitable, an interface film between a polar phase and a nonpolar phase in the micro-emulsion is easier to deform or damage, so that the fly-cutting knife lines can be effectively removed under lower polishing pressure (1-2.5 kPa), the problems of subsurface damage and the like possibly caused by higher polishing pressure are avoided, and the surface roughness after polishing is improved to a certain extent.
Compared with polishing solution containing surfactant, the polishing solution has little improvement degree on the surface roughness after polishing, and the dispersion degree of the polishing solution can also reach the nanometer level (the polishing solution is completely non-particle type polishing solution), but because the polishing solution does not contain the surfactant, only short-chain alcohol is adopted as a double-solvent phase, the polishing solution can not be attached to the surface of KDP crystal and can not cause deliquescence of the KDP crystal, the components of the polishing solution are common organic reagents, the polishing solution can not generate chemical reaction with the KDP crystal, only one of the components (the double-solvent phase) of the polishing solution is needed to carry out simple surface washing after polishing, the surface cleaning can be realized, any impurity residue can not be generated on the surface, and secondary damage and secondary pollution can not be caused. Apparently, the polishing solution containing the surfactant has reduced surface gloss of KDP crystal due to the existence of obvious surfactant residue after polishing.
Further, the polar phase is water or an inorganic salt solution.
The method is used for regulating and controlling the material removal rate according to different initial roughness.
Further, the nonpolar phase is one of n-hexane, cyclohexane, menthane and isopentyl acetate.
Further, the double-solvent phase is one of ethanol, n-propanol, isopropanol and n-butanol.
A preparation method of the polishing solution comprises the following steps:
1) mixing the nonpolar phase and the double-solvent phase according to a certain volume ratio, and uniformly stirring to form a mixed solvent;
2) and dripping the polar phase into the mixed solvent according to the volume ratio, uniformly stirring, and standing to obtain the polishing solution.
The preparation method disclosed by the invention is simple in steps, convenient to operate and stable in property, the prepared polishing solution can effectively remove fly-cutting knife lines under a lower polishing pressure (1-2.5 kPa), and the problems that sub-surface damage is possibly caused by a higher polishing pressure and the like are avoided.
Further, the preparation environment temperature of the polishing solution is 20-35 ℃, the relative humidity is 30-50%, and the air pressure is normal pressure.
The application of the polishing solution is used for polishing the surface of a soft and brittle deliquescent crystal such as a KDP crystal.
Further, the specific application process of the polishing solution is as follows:
and polishing the surface of the crystal by using a precision polishing machine, using the polishing solution in the polishing process, directly washing the surface of a polished sample by using a double-solvent phase reagent in the polishing solution as a cleaning solution after polishing, and then drying by using clean dry gas.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. the invention takes the design of the polishing solution without the surfactant microemulsion as a basic starting point, develops a novel polishing solution system superior to the traditional water-in-oil microemulsion, can realize the polishing effect of removing fly-cutter lines by deliquescence polishing under lower polishing pressure, avoids using the traditional amphiphilic surfactant, is easier to clean the surface after polishing, and does not generate surface organic matter residue.
2. The polishing solution is completely particle-free, and is simple to prepare and stable in property. Controllable corrosion can be realized through deliquescence of the polishing solution in the polishing process, residues on the surface of the KDP crystal after polishing are simple organic solvents, chemical reaction with the KDP crystal cannot occur, the surface of the KDP crystal can be conveniently cleaned through the adoption of the responsive double-solvent-phase organic solvent, and secondary damage to the surface of the KDP crystal cannot be caused.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1(a) is a scanning electron microscope of KDP crystal surface after polishing by using traditional W/O microemulsion;
FIG. 2(b) is a scanning electron microscope scan of KDP crystal surface after polishing with conventional W/O microemulsion and soaking once in isopropanol (10 min);
FIG. 3(c) is a scanning electron microscope image of KDP crystal surface after polishing with conventional W/O microemulsion, soaking three times (10 min/time, 3 times) in isopropanol, and then placing in a moisture-proof cabinet for 2 weeks;
FIG. 4(d) is a scanning electron microscope image of the KDP crystal surface after polishing with surfactant-free microemulsion;
FIG. 5(e) is a scanning electron microscope scan of KDP crystal surface after polishing with surfactant-free microemulsion and soaking once in isopropanol (10 min);
fig. 6(f) is a KDP crystal surface electron microscope scan after polishing with surfactant-free microemulsion, soaking three times (10 min/time, 3 times) in isopropanol, and then placing in a moisture-proof cabinet for 2 weeks.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
Example 1:
the prepared polishing solution is used for KDP crystal polishing, and the specific process is as follows:
1) obtaining of initial surface: KDP crystal with the phi of 50mm obtained by flying cutting of single-point diamond is used as crystal to be polished, and the surface roughness is 3.5 nm;
2) and preparing a polishing solution: mixing a nonpolar phase (cyclohexane) and a double-solvent phase (isopropanol) according to a certain volume ratio, uniformly stirring by magnetic force, and then dropwise adding a certain volume of polar phase (water) into the mixed solvent, wherein the volume ratio of the cyclohexane to the isopropanol to the water in the final system is 36: 604, stirring uniformly, standing, and sealing for later use; in order to compare the advantages of the polishing solution of the invention and the traditional water-in-oil microemulsion, the water-in-oil microemulsion formed by the oil phase (decanol), the surfactant (TX-100) and the water in the ratio of 36:60:4 is used as a comparison group polishing solution;
3) and polishing experiment: polishing two KDP crystals subjected to fly-cutting by respectively adopting the polishing solution and the traditional W/O microemulsion of the invention by adopting a PM6 precision polishing machine, wherein the polishing pressure is 2kPa, the rotating speed of a main disc is 60rpm, the rotating speed of a clamp is 60rpm, the KDP crystals rotate in the same direction, and the polishing time is 5 min;
4) and cleaning after polishing: and (3) taking a double-solvent phase (isopropanol) reagent as a cleaning solution, washing the surface of the polished sample, soaking the sample in the cleaning solution for 10min, and drying the sample by using clean dry gas.
Under the polishing conditions of the embodiment, when the surfactant-free microemulsion-like liquid is used as the polishing liquid, the thickness removal rate of the KDP crystal is 56nm/min, and after polishing and cleaning, the surface roughness of the sample is 2.9 nm. When the control group W/O microemulsion is used as the polishing solution, the thickness removal rate of KDP crystal is 189nm/min, and after polishing and cleaning, the surface roughness of the sample is 3.2 nm.
As shown in fig. 1(a) -3 (c), after polishing with a conventional W/O microemulsion containing a surfactant, a large amount of greasy dirt areas are observed on the surface, after soaking and cleaning with a demulsifier isopropanol, the greasy dirt areas are destroyed into a small liquid film by the isopropanol, and the liquid film is continuously soaked, cleaned and dried in a moisture-proof cabinet (with a relative humidity of 30%), a large amount of solid grains gradually appear on the surface, and the brightness of the surface is reduced.
After the microemulsion-like agent of the surfactant is used for polishing, an oil stain area formed by an organic reagent can not be seen on the surface basically, the surface basically has no obvious change in the process of cleaning by using isopropanol, and solid grains can not be generated in the process of placing.
Example 2-example 17 were obtained by orthogonal experiments:
example 2-example 17 is based on example 1, differing from example 1 in that:
the volume ratio of the nonpolar phase, the solvent phase and the polar phase is different, and the polishing pressure is different.
The specific differences and polishing effects of examples 1-17 are shown in table 1:
TABLE 1
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (5)
1. The polishing solution for KDP crystal is characterized by comprising the following components in percentage by volume:
polar phase: 1-4%;
non-polar phase: 45% -55%;
the balance being a bi-solvent phase;
the polar phase is water, and the nonpolar phase is one of cyclohexane, menthane and isopentyl acetate; the double-solvent phase is one of n-propanol, isopropanol and n-butanol.
2. A method for preparing the polishing solution according to claim 1, comprising the steps of:
1) mixing the nonpolar phase and the double-solvent phase according to a certain volume ratio, and uniformly stirring to form a mixed solvent;
2) and dripping the polar phase into the mixed solvent according to the volume ratio, uniformly stirring, and standing to obtain the polishing solution.
3. The method for preparing the polishing solution according to claim 2, wherein the temperature of the environment for preparing the polishing solution is 20 ℃ to 35 ℃, the relative humidity is 30% to 50%, and the air pressure is normal pressure.
4. Use of the polishing solution according to claim 1 for polishing the surface of a soft, brittle, deliquescent crystal.
5. The application of the polishing solution as set forth in claim 4, wherein the specific application process of the polishing solution is as follows:
and polishing the surface of the KDP crystal by using a precision polishing machine, using the polishing solution in the polishing process, directly washing the surface of a polished sample by using a double-solvent phase reagent in the polishing solution as a cleaning solution after polishing, and then drying by using clean dry gas.
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| CN111763478B (en) * | 2020-07-21 | 2021-11-02 | 中国工程物理研究院机械制造工艺研究所 | Chemical polishing solution for KDP crystal, preparation method and polishing method |
| CN112139859A (en) * | 2020-09-21 | 2020-12-29 | 大连理工大学 | Method for anhydrous polishing of KDP crystal |
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