Prediction method for ultrasonic vibration polishing processing surface generation of optical glass

Abstract

The invention relates to the technical field of hard and brittle material processing, in particular to a prediction method for ultrasonic vibration polishing processing surface generation of optical glass, which comprises the following steps: determining material performance parameters of a polishing tool and an optical glass workpiece; acquiring technological parameters of ultrasonic vibration polishing processing of the optical glass; discretizing the contact area of the polishing tool and the optical glass workpiece and the polishing time; calculating initial contact pressure; calculating the dynamic compression amount of the polishing tool; calculating the dynamic contact pressure intensity of the contact area; calculating the material removal depth of the contact area of the polishing tool and the optical glass; and iteratively executing the steps and accumulating the calculation time, and verifying the integrity of the calculation process by comparing the calculation time with the preset polishing time. The prediction method provided by the invention is relatively high in precision in the aspects of predicting the removal depth and the surface profile of the material, and provides a certain theoretical basis and technical support for researching the formation of the hard and brittle material on the ultrasonic vibration polishing surface.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hard and brittle material processing technology, and particularly relates to a prediction method for surface creation of optical glass ultrasonic vibration polishing processing. BACKGROUND

[0002] With the rapid development of science and technology and social production, the requirements for the processing quality and manufacturing precision of required parts in some important fields such as aerospace, biological medicine and electronic information are becoming more and more strict. Hard and brittle materials represented by optical glass and ceramics are widely used in science and technology frontiers and actual production due to their unique superior performance, and the nearly strict manufacturing requirements make the hard and brittle material processing face great challenges. Generally, polishing processing is the last link of part manufacturing, and plays a key role in ensuring the final quality of products or parts. How to realize efficient, high-precision and green processing of hard and brittle materials such as optical glass is an important issue that needs to be urgently solved in modern manufacturing, and advanced polishing theory and technology are needed to provide support for innovation application and industrial progress.

[0003] Ultrasonic vibration assisted polishing technology (Ultrasonic vibration polishing, UVP) is to improve the action efficiency of the polishing processing area by applying ultrasonic vibration to the polishing tool or workpiece, so as to improve the processing efficiency and obtain a processing surface with nanometer level roughness. Therefore, the technology has broad application prospects in the ultraprecision machining of hard and brittle materials such as optical glass and ceramics. Due to the high hardness and brittleness of hard and brittle materials at the present stage, surface microcracks and subsurface damage are easily generated in the processing process, causing quality problems of the workpiece, so it is urgent to develop a prediction method for surface creation of optical glass ultrasonic vibration polishing processing, so as to realize high-quality shape control and property manufacturing of the workpiece surface. SUMMARY

[0004] In order to solve the problems in the prior art, the present application provides a prediction method for surface creation of optical glass ultrasonic vibration polishing processing, which specifically comprises the following steps: Determine the material performance parameters of the polishing tool and the optical glass workpiece.

[0005] Obtain the process parameters of the optical glass ultrasonic vibration polishing processing, the process parameters including a preset polishing time.

[0006] Discretize the contact area of the polishing tool and the optical glass workpiece and the polishing time, and output the discrete results.

[0007] Calculate the initial contact pressure based on the process parameters and the discrete results.

[0008] calculating a dynamic compression amount of the polishing tool based on the initial contact pressure and material property parameters.

[0009] calculating a dynamic contact pressure of the contact area based on the dynamic compression amount.

[0010] calculating a material removal depth of the contact area between the polishing tool and the optical glass using the Preston equation.

[0011] iteratively performing all the above steps and accumulating a calculation time, and verifying completeness of the calculation process by comparing the calculation time with the preset polishing time.

[0012] Further, the material property parameters include a polishing tool thickness, a polishing tool radius, and a Young's modulus of the polishing tool.

[0013] Further, the process parameters further include a spindle speed of a polishing machine, an ultrasonic amplitude, an ultrasonic frequency, and a pre-polishing force.

[0014] Further, the contact area between the polishing tool and the optical glass workpiece is discretized into a plurality of micro-annular discrete units along a radial direction of the polishing tool, and the polishing time is discretized into a plurality of time intervals.

[0015] Further, at an initial time , the initial contact pressure of any micro-annular discrete unit in the contact area is:

[0016] wherein, represents the initial contact pressure of the discrete unit in the contact area, represents a distance of a discrete point of the polishing tool from the origin, represents a distance between adjacent discrete points, represents the pre-polishing force, represents the polishing tool radius.

[0017] Further, the polishing tool is composed of a ceramic base and a polyurethane polishing pad. Since the hardness of the base is much greater than that of the polishing pad and is not easy to compress, the deformation of the polishing tool is considered to only come from the polishing pad during the model establishment. When the time-varying nature of the contact pressure is not considered, the dynamic compression amount of the polishing tool changing with the ultrasonic vibration is composed of two parts, one part is the elastic deformation of the polishing pad caused by the pre-polishing force of the polishing tool, and the other part is the elastic deformation caused by the ultrasonic vibration. Considering the material removal depth and the time-varying nature of the contact pressure, the time is discretized, and the dynamic compression amount of each discrete unit is represented as:

[0018] in, For the thickness of the polishing pad, Young's modulus of the polishing tool, Ultrasonic amplitude, For ultrasonic frequency, For the initial phase, To account for the time-varying pressure at time t, the contact pressure between each discrete element and the workpiece is considered. The material removal depth is applied to each discrete unit.

[0019] Furthermore, a coordinate system is established with the center of the polishing tool as the origin. The horizontal axis represents the direction of movement perpendicular to the polishing tool, the vertical axis represents the direction of movement parallel to the polishing tool, and the horizontal axis represents the direction perpendicular to the workpiece surface. The x-coordinates of discrete points on the polishing tool are represented. The ordinate of the discrete points of the polishing tool; Furthermore, based on the aforementioned dynamic compression amount Calculate the dynamic contact pressure distribution function : .

[0020] Furthermore, a material removal function considering time-varying pressure effects is established. :

[0021] Where, k Represents the Preston coefficient. Indicates the contact area between the polishing tool and the workpiece with respect to time. The pressure distribution function, This represents the velocity distribution function of the polishing tool. Indicates the duration of the unit's stay; Furthermore, regarding time By accumulating points, you can obtain the time spent in the area. Material removal depth distribution function : .

[0022] Furthermore, regarding time Discretize and remove the material depth function. It can be represented as:

[0023] in, Represents the time interval after time discretization. Indicates the rotation speed of the polishing tool. Represented as the radius of the polishing tool A changing function, These are parameters to be determined.

[0024] Furthermore, summing over discrete time yields the value of the first time step (i.e., the time step) along the radius of the polishing tool during the entire ultrasonic vibration polishing process of the moving optical glass. Material removal depth of each discrete unit for:

[0025] in, Indicates the cycle of motion. This indicates the time of each movement cycle. Indicates the first The x-coordinate of each discrete unit, express Time of the first Polishing tool and straight line at each discrete unit The x-coordinate of the intersection point express Time of the first Polishing tool and straight line at each discrete unit The ordinate of the intersection point, This represents the resultant velocity at the intersection point. For the first Discrete time moments Indicates the number of discrete moments. Indicates the first The contact time between each discrete unit and the workpiece. Indicates the polishing tool along The axial direction will be the radius Discrete quantity, This represents the pressure distribution function at the intersection point. Represents the time of each discrete unit at time... The depth of material removal.

[0026] Compared with the prior art, the present invention has the following beneficial effects: This invention innovatively integrates the time-varying coupling effect of contact pressure and material removal depth into the material removal model. Traditional models often treat contact pressure as constant, while this invention recognizes that the workpiece surface morphology changes continuously as polishing progresses, leading to dynamic changes in contact pressure, which in turn affects the subsequent material removal rate. By establishing and solving this dynamic coupling model, this method can more realistically simulate the actual polishing process, thereby achieving higher accuracy in predicting material removal depth and the final workpiece surface profile.

[0027] This invention constructs a multi-parameter, multi-physics coupled deterministic model by finely discretizing the polishing time and tool contact area, and combining this with the dynamic compression caused by ultrasonic vibration. This model is not only applicable to fixed-point polishing, but also more comprehensively describes the polishing process of a tool moving along a straight line in reciprocating motion, fully considering the velocity synthesis and instantaneous contact state at different locations. This allows the model to flexibly adapt to different process parameters, providing a powerful analytical tool for process optimization.

[0028] This invention is the first to explicitly decompose the dynamic compression of a polishing tool into two parts: pre-compression elastic deformation and ultrasonic vibration deformation, and introduces a corrected Preston coefficient to account for uneven abrasive particle distribution. This modeling approach is not merely a computational tool; more importantly, it reveals at the mechanistic level how ultrasonic vibration enhances material removal by altering instantaneous contact pressure and tool-workpiece interaction, and how the elasticity of the polishing pad and vibration synergistically influence surface creation. This lays a solid theoretical foundation for a deeper understanding of the advantages of UVP technology.

[0029] The method of this invention achieves quantitative and predictive analysis from process parameter input to surface morphology output. Through this model, the processing effects under different parameter combinations can be simulated in advance before actual processing, thereby guiding the selection of optimal process parameters and enabling proactive control of the workpiece surface contour and material removal amount. This helps reduce trial-and-error costs, improve processing consistency and reliability, and ultimately promotes the development of ultra-precision machining of hard and brittle materials such as optical glass towards more efficient, higher precision, and more controllable precision machining.

[0030] The time-varying coupled discretization modeling framework established in this invention is not limited to the optical glass UVP processing described above. Its core ideas and methodology can be extended to the modeling and prediction of precision processing processes such as ultrasonic-assisted polishing and grinding of other hard and brittle materials, and has good industry reference and promotion value.

[0031] In summary, this invention not only provides a high-precision prediction tool, but more importantly, through innovative modeling methods, it profoundly reveals the complex physical nature of the UVP process, providing a theoretical basis and technical support for the study of surface creation of hard and brittle materials in ultrasonic vibration polishing. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1This is a flowchart illustrating the calculation of the material removal model in the ultrasonic vibration polishing process of this invention.

[0034] Figure 2 This is a schematic diagram illustrating the ultrasonic vibration polishing time and the surface dispersion of the polishing tool according to the present invention.

[0035] Figure 3 This is a schematic diagram of the motion trajectory and compression model of the polishing tool of the present invention.

[0036] Figure 4 This is a schematic diagram of the surface contour processed by ultrasonic vibration polishing according to the present invention.

[0037] Figure 5 This is a schematic diagram showing the relative positions of the polishing tool and the workpiece at different times according to the present invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] like Figure 1 As shown, this invention discloses a method for predicting surface formation during ultrasonic vibration polishing of optical glass, mainly including the following steps: S1: Determine the material properties of the polishing tools and optical glass workpieces.

[0041] In a preferred embodiment of this application, the material performance parameters include the polishing tool thickness, polishing tool radius, and Young's modulus of the polishing tool.

[0042] S2: Obtain the process parameters for ultrasonic vibration polishing of optical glass, including a preset polishing time.

[0043] As a preferred embodiment of this application, the process parameters also include the spindle speed of the polishing machine tool, the ultrasonic amplitude, the ultrasonic frequency, and the pre-polishing force.

[0044] S3: Discretize the contact area between the polishing tool and the optical glass workpiece, as well as the polishing time, and output the discrete results.

[0045] In a preferred embodiment of this application, the contact area between the polishing tool and the optical glass workpiece is discretized into several micro-ring discrete units along the radial direction of the polishing tool, and the polishing time is discretized into several time intervals.

[0046] S4: Calculate the initial contact pressure based on the process parameters and discrete results.

[0047] As a preferred embodiment of this application, at the initial time The initial contact pressure of any micro-ring discrete unit within the contact area for:

[0048] in, This represents the initial contact pressure of the discrete element within the contact region. This represents the distance of discrete points of the polishing tool from the origin. Represents the distance between adjacent discrete points. Indicates pre-polishing force. Indicates the radius of the polishing tool.

[0049] S5: Calculate the dynamic compression of the polishing tool based on the initial contact pressure and material property parameters.

[0050] In a preferred embodiment of this application, the polishing tool consists of a ceramic substrate and a polyurethane polishing pad. Since the hardness of the substrate is much greater than that of the polishing pad and it is not easily compressed, the deformation of the polishing tool is considered to originate only from the polishing pad during model building. When the time-varying nature of contact pressure is not considered, the dynamic compression of the polishing tool with ultrasonic vibration is... It consists of two parts: one part is the elastic deformation of the polishing pad caused by the pre-polishing force of the polishing tool, and the other part is the elastic deformation caused by ultrasonic vibration. Considering the time-varying nature of material removal depth and contact pressure, time is used... After discretization, the dynamic compression of each discrete unit Represented as:

[0051] in, For the thickness of the polishing pad, Young's modulus of the polishing tool, Ultrasonic amplitude, For ultrasonic frequency, For the initial phase, To account for the time-varying pressure at time t, the contact pressure between each discrete element and the workpiece is considered. The material removal depth is applied to each discrete unit.

[0052] S6: Calculate the dynamic contact pressure of the contact area based on the dynamic compression amount.

[0053] In a preferred embodiment of this application, a coordinate system is established with the center of the polishing tool as the origin. The horizontal axis is perpendicular to the direction of movement of the polishing tool, the vertical axis is parallel to the direction of movement of the polishing tool, and the vertical axis is perpendicular to the surface of the workpiece. The x-coordinates of discrete points on the polishing tool are represented. The vertical coordinates represent the discrete points of the polishing tool.

[0054] Based on dynamic compression Calculate the dynamic contact pressure distribution function : .

[0055] S7: The Preston equation is used to calculate the material removal depth in the contact area between the polishing tool and the optical glass.

[0056] As a preferred embodiment of this application, a material removal function considering the time-varying effect of pressure is established. :

[0057] Where, k Represents the Preston coefficient. Indicates the contact area between the polishing tool and the workpiece with respect to time. The pressure distribution function, This represents the velocity distribution function of the polishing tool. Indicates the duration of the unit's stay; As a preferred embodiment of this application, regarding time... By accumulating points, you can obtain the time spent in the area. Material removal depth distribution function : .

[0058] As a preferred embodiment of this application, regarding time... Discretize and remove the material depth function. It can be represented as:

[0059] in, Represents the time interval after time discretization. Indicates the rotation speed of the polishing tool. Represented as the radius of the polishing tool A changing function, These are parameters to be determined.

[0060] As a preferred embodiment of this application, Summing over discrete time intervals yields the time interval along the radius of the polishing tool during the entire ultrasonic vibration polishing process of the moving optical glass. Material removal depth of each discrete unit for:

[0061] in, Indicates the cycle of motion. This indicates the time of each movement cycle. Indicates the first The x-coordinate of each discrete unit, express Time of the first Polishing tool and straight line at each discrete unit The x-coordinate of the intersection point express Time of the first Polishing tool and straight line at each discrete unit The ordinate of the intersection point, This represents the resultant velocity at the intersection point. For the first Discrete time moments Indicates the number of discrete moments. Indicates the first The contact time between each discrete unit and the workpiece. Indicates the polishing tool along The axial direction will be the radius Discrete quantity, This represents the pressure distribution function at the intersection point. Represents the time of each discrete unit at time... The depth of material removal.

[0062] S8: Iteratively execute all the above steps and accumulate the calculation time. Verify the integrity of the calculation process by comparing the calculation time with the preset polishing time.

[0063] This invention establishes a time-varying model that dynamically couples contact pressure and material removal depth, and performs fine discretization of the polishing area and time, thereby achieving high-precision material removal and surface morphology prediction, providing a theoretical basis for process optimization and quality control.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting the creation of a surface by ultrasonic polishing of optical glass, characterized in that, The method comprises the following steps: determining material performance parameters of the polishing tool and the optical glass workpiece; obtaining process parameters of the ultrasonic vibration polishing of the optical glass, wherein the process parameters comprise a preset polishing time; discretizing the contact area between the polishing tool and the optical glass workpiece and the polishing time, and outputting a discrete result; calculating an initial contact pressure based on the process parameters and the discrete result; calculating a dynamic compression amount of the polishing tool based on the initial contact pressure and the material performance parameters; calculating a dynamic contact pressure of the contact area based on the dynamic compression amount; calculating a material removal depth of the contact area between the polishing tool and the optical glass by using a Preston equation; iteratively performing all the above steps and accumulating a calculation time, and verifying the completeness of the calculation process by comparing the calculation time with the preset polishing time.

2. A prediction method for surface creation by ultrasonic vibration polishing of optical glass according to claim 1, characterized in that, The material performance parameters comprise a thickness of the polishing tool, a radius of the polishing tool and a Young's modulus of the polishing tool.

3. A prediction method for surface creation by ultrasonic vibration polishing of optical glass according to claim 1, characterized in that, The process parameters further comprise a spindle speed of a polishing machine tool, an ultrasonic amplitude, an ultrasonic frequency and a pre-polishing force.

4. The method of claim 1, wherein the method is used for the surface creation of optical glass by ultrasonic vibration polishing. The contact area between the polishing tool and the optical glass workpiece is discretized into a plurality of micro-ring discrete units along a radius direction of the polishing tool, and the polishing time is discretized into a plurality of time intervals.

5. A prediction method for surface creation by ultrasonic vibration polishing of optical glass according to claim 4, characterized in that, At the initial time The initial contact pressure of any microannular discrete element in the contact area is: wherein, represents the initial contact pressure of the discrete elements within the contact zone, represents the distance of a discrete point of the polishing tool from the origin, represents the distance between adjacent discrete points, represents the pre-polishing force, represents the radius of the polishing tool.

6. A prediction method for surface creation by ultrasonic vibration polishing of optical glass according to claim 5, wherein The polishing tool is composed of a ceramic base and a polyurethane polishing pad. Since the hardness of the base is much greater than that of the polishing pad and is not easy to compress, the deformation of the polishing tool is considered to come only from the polishing pad during the modeling process. When the time-varying nature of the contact pressure is not considered, the dynamic compression amount of the polishing tool changes with the ultrasonic vibration The polishing tool is composed of a ceramic base and a polyurethane polishing pad. Since the hardness of the base is much greater than that of the polishing pad and is not easy to compress, the deformation of the polishing tool is considered to come only from the polishing pad during the modeling process. When the time-varying nature of the contact pressure is not considered, the dynamic compression amount of the polishing tool changes with the ultrasonic vibration After discretization, the dynamic compression amount of each discrete unit is expressed as: wherein, is the thickness of the polishing pad, is the Young's modulus of the polishing tool, is the ultrasonic amplitude, is the ultrasonic frequency, is the initial phase, is the contact pressure of each discrete element with the workpiece taking into account the time-varying pressure at time t, is the material removal depth of each discrete element.

7. A prediction method for optical glass ultrasonic vibration polishing surface creation according to claim 6, characterized in that, A coordinate system is established with the center of the polishing tool as the origin, the horizontal coordinate axis is perpendicular to the movement direction of the polishing tool, the vertical coordinate axis is parallel to the movement direction of the polishing tool, and the vertical coordinate axis is perpendicular to the direction of the workpiece surface, represents the horizontal coordinate of the discrete point of the polishing tool, represents the vertical coordinate of the discrete point of the polishing tool; based on the dynamic compression amount computing a dynamic contact pressure distribution function : 。 8. The method for predicting the surface creation of optical glass ultrasonic vibration polishing according to claim 7, wherein, Establishing material removal function considering pressure time-varying effect : Where, k Represents the Preston coefficient. Indicates the contact area between the polishing tool and the workpiece with respect to time. The pressure distribution function, This represents the velocity distribution function of the polishing tool. Indicates the duration of the unit's stay; over time Integrating over time yields the material removal depth distribution function after a dwell time 。 9. The method for predicting the surface creation of optical glass ultrasonic vibration polishing according to claim 8, wherein, To time Discretization, material removal depth function is represented as: wherein denotes the time interval after time discretization, denotes the polishing tool rotational speed, denotes a function that varies as a function of the polishing tool radius r, is a pending parameter.

10. The method for predicting the surface creation of optical glass ultrasonic vibration polishing processing according to claim 9, wherein, The discrete time summation gives the material removal depth of the first discrete unit on the radius of the polishing tool during the entire mobile optical glass ultrasonic vibration polishing process is: in, Indicates the cycle of motion. This indicates the time of each movement cycle. Indicates the first The x-coordinate of each discrete unit, express Time of the first Polishing tool and straight line at each discrete unit The x-coordinate of the intersection point express Time of the first Polishing tool and straight line at each discrete unit The ordinate of the intersection point, This represents the resultant velocity at the intersection point. For the first Discrete time moments Indicates the number of discrete moments. Indicates the first The contact time between each discrete unit and the workpiece. Indicates the polishing tool along The axial direction will be the radius Discrete quantity, This represents the pressure distribution function at the intersection point. Represents the time of each discrete unit at time... The depth of material removal.

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