A method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology

Abstract

The present invention discloses a method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology, which relates to the technical field of metal polishing, including: establishing a numerical model of the surface morphology of the outer wall of a metal object, simulating the changing law of the surface morphology during the polishing process; selecting a Gaussian laser heat source, setting laser beam parameters, and establishing a numerical model of the instantaneous laser state; improving the morphology of the outer wall of the metal object by two methods, namely, melting flow and vaporization removal; studying the temperature field distribution and the change of the surface morphology of the outer wall of the metal object under different laser parameters; judging whether microcracks appear on the outer wall of the metal object after polishing; evaluating the polishing effect of the outer wall of the metal object under each combination of laser parameters; and outputting the best laser parameter configuration combination suitable for the current polishing task. By combining numerical simulation with experimental analysis, the changing law of the surface morphology during the polishing process is simulated, and the microcrack phenomenon after polishing is specifically studied.

Description

Technical Field

[0001] The invention relates to the technical field of metal polishing, and in particular to a method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology. Background Art

[0002] Laser polishing technology is a widely used special processing technology. It realizes non-contact processing between polishing equipment and materials through the interaction between laser beam and material surface. Laser polishing technology is based on the polishing mechanism of melting flow and vaporization removal. The laser beam heats the material surface, causing the material to melt, flow and solidify, thereby achieving the purpose of polishing.

[0003] The quality of the mold surface determines its service life. The final polishing process of the mold is very complicated, especially for small and high-precision molds. The polishing process takes up a lot of time and cost in the processing process, but it is ultimately difficult to obtain the ideal surface accuracy. At the same time, the stability of the material surface quality is also difficult to guarantee. Summary of the invention

[0004] In order to solve the above technical problems, a method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology is provided. This technical solution solves the problems raised in the above background technology.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology, comprising:

[0007] By combining numerical simulation with experimental analysis, a numerical model of the surface morphology of the outer wall of the metal object is established to simulate the changing law of the surface morphology during the polishing process.

[0008] Select a Gaussian laser heat source, set laser beam parameters, and establish a numerical model of instantaneous laser state, wherein the laser beam parameters include amplitude, lateral variance, longitudinal variance, laser wavelength, laser power, scanning speed, and pulse width;

[0009] The laser beam acts on the outer wall of the metal object, improving the outer wall morphology of the metal object through two methods: melting flow and vaporization removal;

[0010] The temperature field distribution and surface morphology changes of the outer wall of the metal object under different laser parameters were studied by single factor experimental method.

[0011] Determine whether microcracks appear on the outer wall of the metal object after polishing. If so, output that the laser parameters used for polishing the outer wall are unqualified; if not, output that the laser parameters used for polishing the outer wall are qualified;

[0012] By calculating the roughness and glossiness indexes of the outer surface of the metal object, the polishing effect of the outer surface of the metal object under each combination of qualified laser parameters is evaluated;

[0013] Based on the polishing effect of the outer wall of the metal object under each combination of qualified laser parameters, the optimal laser parameter configuration combination suitable for the current polishing task is output.

[0014] Preferably, the method of combining numerical simulation with experimental analysis to establish a numerical model of the surface morphology of the outer wall of the metal object and simulate the change law of the surface morphology during the polishing process specifically includes:

[0015] Define the geometry and material properties of the numerical model of the surface morphology;

[0016] For the outer wall of metal objects, geometric modeling is performed according to their actual shapes;

[0017] Collect and input physical properties of the outer wall material of the metal object, wherein the physical properties include density, thermal conductivity and specific heat capacity;

[0018] Divide the model based on the geometric shape and physical field distribution characteristics of the surface morphology numerical model;

[0019] Conduct simulation experiments on the polishing process to simulate the heat exchange and mechanical interaction between the outer surface of the metal object and the surrounding environment during the polishing process;

[0020] The reliability of the model is verified by comparing the numerical simulation results with the simulation experimental results, and the surface morphology numerical model is optimized and adjusted.

[0021] Preferably, the steps of selecting a Gaussian laser heat source, setting laser beam parameters, and establishing a numerical model of an instantaneous laser state specifically include:

[0022] A Gaussian laser heat source is selected as the polishing laser beam;

[0023] Preset Gaussian laser beam parameters;

[0024] Calculate a two-dimensional Gaussian laser energy distribution function based on a preset amplitude, transverse variance, and longitudinal variance;

[0025] Obtain the heat conduction equation during laser polishing;

[0026] Using the heat conduction equation, calculate the temperature function value of each point in the surface morphology numerical model of the outer wall of the metal object;

[0027] Based on the temperature field distribution of the outer wall of the metal object under different laser parameters, a numerical model of the instantaneous laser state is constructed and output;

[0028] The two-dimensional Gaussian laser energy distribution function is: ,

[0029] In the formula, is the two-dimensional Gaussian laser energy distribution function, is the energy intensity amplitude of the laser center point, is the coordinate of the laser center point, are the lateral variance and longitudinal variance of the laser beam, respectively;

[0030] The heat conduction equation is: ,

[0031] In the formula, is the density of the metal, is the specific heat capacity of metal, is the thermal conductivity of the metal, is the temperature function of each point in the numerical model of the surface morphology of the outer wall of the metal object, For time, represents the partial derivative of the temperature function with respect to time.

[0032] Preferably, the laser beam acts on the outer wall of the metal object, and improving the outer wall morphology of the metal object by two methods of melting flow and vaporization removal specifically includes:

[0033] The Gaussian laser heat source emits a laser beam. After the material absorbs the laser energy, the surface temperature rises and is quickly transmitted into the material.

[0034] When the surface temperature of the material reaches the melting threshold, the surface metal begins to melt and flow. Under the action of surface tension, the liquid metal flows and fills the valleys on the surface of the material.

[0035] When the surface temperature of the material continues to rise and reaches the vaporization threshold, the surface material is removed by vaporization, and the vaporization expansion and plasma impact further affect the surface morphology of the metal material.

[0036] Preferably, the single factor experimental method is used to study the temperature field distribution and surface morphology changes of the outer wall of the metal object under different laser parameters, and specifically includes:

[0037] Controlling other laser beam parameters to fixed values, changing the value of one laser beam parameter to conduct at least two laser beam polishing experiments on the outer wall of the metal object;

[0038] Based on the heat conduction equation in the laser polishing process, the temperature field distribution of the outer wall of the metal object in the laser beam polishing experiment is calculated;

[0039] After the laser beam polishing experiment, the outer wall of the metal object was remodeled, and the numerical models of the surface morphology before and after the experiment were compared to obtain the changes in the surface morphology.

[0040] Preferably, the step of judging whether microcracks appear on the outer wall of the metal object after polishing specifically comprises:

[0041] S101: Use a high-power magnifying glass to directly observe the outer surface of the polished metal object along the path of the laser scan;

[0042] S102: Determine whether there are fine lines or mesh structures on the outer wall of the metal object. If so, output that there are microcracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are unqualified. If not, no output is made;

[0043] S103: Clean and dry the metal sample, observe the microstructure of the outer wall of the metal sample using an electron microscope, and record possible microcrack locations;

[0044] S104: Subsurface damage detection of possible microcrack locations using a focused ion beam dual beam system;

[0045] S105: Cutting metal samples with a focused ion beam dual-beam system and measuring the crack depth of the cross section after cutting;

[0046] S106: Determine whether the crack depth is higher than the micro-crack depth threshold. If so, output that there are micro-cracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are unqualified. If not, no output is made.

[0047] S107: Use a microhardness tester to test the hardness of the metal surface before and after polishing;

[0048] S108: Determine whether the surface hardness of the metal after polishing is higher than that before polishing. If so, output that there are no microcracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are qualified. If not, output that there may be microcracks on the outer wall of the metal object and return to step S103.

[0049] Preferably, the step of evaluating the polishing effect of the outer wall of the metal object under each set of qualified laser parameters by calculating the roughness and glossiness index of the outer wall of the metal object specifically includes:

[0050] Based on the surface morphology numerical model of the outer wall of the metal object after the polishing experiment, the height difference of each point on the outer wall of the metal object relative to the table plane is measured;

[0051] Calculate the root mean square value of the height difference of each point on the outer wall of the metal object relative to the average plane, and output it as the roughness index of the outer wall of the metal object;

[0052] Use a gloss meter to measure the intensity of light reflected from the outer wall of a metal object, and use the gloss formula to calculate and output its gloss index;

[0053] Preset roughness index weight and glossiness index weight;

[0054] The polishing effect formula is used to calculate the polishing effect of the outer wall of the metal object under each combination of qualified laser parameters;

[0055] The roughness index is: ,

[0056] In the formula, is the roughness index, is the total number of sampling points on the outer wall of the metal object, is the height difference between the sampling point on the outer wall of the ith metal object and the table surface;

[0057] The gloss formula is: ,

[0058] In the formula, is the gloss index, is the intensity of the incident light of the gloss meter, It is the intensity of light reflected from the outer wall of a metal object;

[0059] The polishing effect formula is: ,

[0060] In the formula, The polishing effect of the outer wall of the metal object under each group of qualified laser parameters. They are the roughness index weight and glossiness index weight respectively.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] By optimizing the laser parameters, efficient polishing of the metal surface can be achieved in a short time, which significantly improves production efficiency. The ups and downs on the material surface can be removed to obtain a flatter and smoother surface morphology, significantly improving the surface quality of the metal object. At the same time, laser polishing can also improve the hardness and wear resistance of the material surface, extend the service life of the metal object, and reduce production costs and environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a flow chart of the metal object outer wall polishing control method based on the laser beam processing technology of the present invention;

[0064] Figure 2 A flow chart of a method for establishing a surface morphology numerical model of an outer wall of a metal object according to the present invention;

[0065] Figure 3 A flow chart of a method for establishing a numerical model of an instantaneous laser state according to the present invention;

[0066] Figure 4 This is a flow chart of the method for improving the outer wall morphology of a metal object according to the present invention;

[0067] Figure 5 This is a flow chart of the method for studying the temperature field distribution and surface morphology change of the outer wall of a metal object under different laser parameters of the present invention;

[0068] Figure 6 A flow chart of a method for determining whether microcracks appear on the outer wall of a metal object after polishing according to the present invention;

[0069] Figure 7 The present invention is a flow chart of a method for evaluating the polishing effect of the outer wall of a metal object under various combinations of laser parameters. DETAILED DESCRIPTION

[0070] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0071] Reference Figure 1 As shown, a method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology comprises:

[0072] By combining numerical simulation with experimental analysis, a numerical model of the surface morphology of the outer wall of the metal object is established to simulate the changing law of the surface morphology during the polishing process.

[0073] Select a Gaussian laser heat source, set laser beam parameters, and establish a numerical model of instantaneous laser state, wherein the laser beam parameters include amplitude, lateral variance, longitudinal variance, laser wavelength, laser power, scanning speed, and pulse width;

[0074] The laser beam acts on the outer wall of the metal object, improving the outer wall morphology of the metal object through two methods: melting flow and vaporization removal;

[0075] The temperature field distribution and surface morphology changes of the outer wall of the metal object under different laser parameters were studied by single factor experimental method.

[0076] Determine whether microcracks appear on the outer wall of the metal object after polishing. If so, output that the laser parameters used for polishing the outer wall are unqualified; if not, output that the laser parameters used for polishing the outer wall are qualified;

[0077] By calculating the roughness and glossiness indexes of the outer surface of the metal object, the polishing effect of the outer surface of the metal object under each combination of qualified laser parameters is evaluated;

[0078] Based on the polishing effect of the outer wall of the metal object under each combination of qualified laser parameters, the optimal laser parameter configuration combination suitable for the current polishing task is output.

[0079] Reference Figure 2As shown in the figure, by combining numerical simulation with experimental analysis, a numerical model of the surface morphology of the outer wall of the metal object is established, and the change law of the surface morphology during the polishing process is simulated, which specifically includes:

[0080] Define the geometry and material properties of the numerical model of the surface morphology;

[0081] For the outer wall of metal objects, geometric modeling is performed according to their actual shapes;

[0082] Collect and input physical properties of the outer wall material of the metal object, wherein the physical properties include density, thermal conductivity and specific heat capacity;

[0083] Divide the model based on the geometric shape and physical field distribution characteristics of the surface morphology numerical model;

[0084] Conduct simulation experiments on the polishing process to simulate the heat exchange and mechanical interaction between the outer surface of the metal object and the surrounding environment during the polishing process;

[0085] The reliability of the model is verified by comparing the numerical simulation results with the simulation experimental results, and the surface morphology numerical model is optimized and adjusted.

[0086] Understanding material properties (such as density, thermal conductivity, and specific heat capacity) helps to more accurately simulate the heat exchange and mechanical interaction during the polishing process during the simulation, thereby optimizing the laser polishing parameters and achieving better polishing results. Through reasonable model division, the calculation cost and time can be reduced while ensuring the simulation accuracy.

[0087] Reference Figure 3 As shown, a Gaussian laser heat source is selected, laser beam parameters are set, and a numerical model of the instantaneous laser state is established, specifically including:

[0088] A Gaussian laser heat source is selected as the polishing laser beam;

[0089] Preset Gaussian laser beam parameters;

[0090] Calculate a two-dimensional Gaussian laser energy distribution function based on a preset amplitude, transverse variance, and longitudinal variance;

[0091] Obtain the heat conduction equation during laser polishing;

[0092] Using the heat conduction equation, calculate the temperature function value of each point in the surface morphology numerical model of the outer wall of the metal object;

[0093] Based on the temperature field distribution of the outer wall of the metal object under different laser parameters, a numerical model of the instantaneous laser state is constructed and output;

[0094] The two-dimensional Gaussian laser energy distribution function is: ,

[0095] In the formula, is the two-dimensional Gaussian laser energy distribution function, is the energy intensity amplitude of the laser center point, is the coordinate of the laser center point, are the lateral variance and longitudinal variance of the laser beam, respectively;

[0096] The heat conduction equation is: ,

[0097] In the formula, is the density of the metal, is the specific heat capacity of metal, is the thermal conductivity of the metal, is the temperature function of each point in the numerical model of the surface morphology of the outer wall of the metal object, For time, represents the partial derivative of the temperature function with respect to time.

[0098] Gaussian laser heat source has the characteristic of concentrated energy distribution. Its energy density is highest at the center of the spot and gradually decreases with the distance from the center of the spot. This energy distribution pattern is conducive to achieving local high-precision polishing, ensuring that the polishing area obtains sufficient energy to achieve melting, flow and vaporization removal of the material, while avoiding unnecessary thermal effects on the surrounding areas.

[0099] Reference Figure 4 As shown, the laser beam acts on the outer wall of the metal object, and improves the outer wall morphology of the metal object through two methods: melting flow and vaporization removal. Specifically, the following methods are used:

[0100] The Gaussian laser heat source emits a laser beam. After the material absorbs the laser energy, the surface temperature rises and is quickly transmitted into the material.

[0101] When the surface temperature of the material reaches the melting threshold, the surface metal begins to melt and flow. Under the action of surface tension, the liquid metal flows and fills the valleys on the surface of the material.

[0102] When the surface temperature of the material continues to rise and reaches the vaporization threshold, the surface material is removed by vaporization, and the vaporization expansion and plasma impact further affect the surface morphology of the metal material.

[0103] When the surface temperature of the material reaches the melting threshold, the surface metal begins to melt and flow. Under the action of surface tension, the liquid metal can flow and fill the valleys on the surface of the material, thereby achieving initial surface smoothing. This process helps to eliminate tiny bumps and depressions on the surface of the material and improve the smoothness and flatness of the surface. When the surface temperature of the material continues to rise to the vaporization threshold, the surface material is removed by vaporization. The vaporization expansion and plasma impact further affect the surface morphology of the metal material, which helps to remove surface attachments, oxides and other impurities. This process can further optimize the surface quality and improve the surface finish and gloss.

[0104] Reference Figure 5 As shown in the figure, the temperature field distribution and surface morphology changes of the outer wall of the metal object under different laser parameters are studied by single factor experimental method, including:

[0105] Controlling other laser beam parameters to fixed values, changing the value of one laser beam parameter to conduct at least two laser beam polishing experiments on the outer wall of the metal object;

[0106] Based on the heat conduction equation in the laser polishing process, the temperature field distribution of the outer wall of the metal object in the laser beam polishing experiment is calculated;

[0107] After the laser beam polishing experiment, the outer wall of the metal object was remodeled, and the numerical models of the surface morphology before and after the experiment were compared to obtain the changes in the surface morphology.

[0108] By fixing other laser beam parameters and changing only one parameter value for at least two experiments, we can accurately explore the specific impact of this parameter on the polishing effect of the outer wall of the metal object, which helps to deeply understand the parameter optimization in the laser polishing process. The single variable experimental design can eliminate the interference of other factors, making the experimental results more accurate and reliable, and facilitating subsequent data analysis and mechanism summary.

[0109] Reference Figure 6 As shown in the figure, judging whether microcracks appear on the outer wall of the metal object after polishing specifically includes:

[0110] S101: Use a high-power magnifying glass to directly observe the outer surface of the polished metal object along the path of the laser scan;

[0111] S102: Determine whether there are fine lines or mesh structures on the outer wall of the metal object. If so, output that there are microcracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are unqualified. If not, no output is made;

[0112] S103: Clean and dry the metal sample, observe the microstructure of the outer wall of the metal sample using an electron microscope, and record possible microcrack locations;

[0113] S104: Subsurface damage detection of possible microcrack locations using a focused ion beam dual beam system;

[0114] S105: Cutting metal samples with a focused ion beam dual-beam system and measuring the crack depth of the cross section after cutting;

[0115] S106: Determine whether the crack depth is higher than the micro-crack depth threshold. If so, output that there are micro-cracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are unqualified. If not, no output is made.

[0116] S107: Use a microhardness tester to test the hardness of the metal surface before and after polishing;

[0117] S108: Determine whether the surface hardness of the metal after polishing is higher than that before polishing. If so, output that there are no microcracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are qualified. If not, output that there may be microcracks on the outer wall of the metal object and return to step S103.

[0118] When using a high-power magnifying glass for observation, you need to pay attention to the angle and intensity of the light source to ensure that the surface details can be clearly seen; using an electron microscope to detect microcracks usually requires sample pretreatment, such as cleaning, drying, and gold spraying, to improve image clarity and contrast; hardness testing can indirectly reflect the microcracks on the metal surface. If the hardness of the metal surface is significantly reduced after polishing, it may be caused by microcracks.

[0119] Reference Figure 7 As shown, by calculating the roughness and glossiness indexes of the outer wall of the metal object, the polishing effect of the outer wall of the metal object under each set of qualified laser parameters is evaluated, including:

[0120] Based on the surface morphology numerical model of the outer wall of the metal object after the polishing experiment, the height difference of each point on the outer wall of the metal object relative to the table plane is measured;

[0121] Calculate the root mean square value of the height difference of each point on the outer wall of the metal object relative to the average plane, and output it as the roughness index of the outer wall of the metal object;

[0122] Use a gloss meter to measure the intensity of light reflected from the outer wall of a metal object, and use the gloss formula to calculate and output its gloss index;

[0123] Preset roughness index weight and glossiness index weight;

[0124] The polishing effect formula is used to calculate the polishing effect of the outer wall of the metal object under each combination of qualified laser parameters;

[0125] The roughness index is: ,

[0126] In the formula, is the roughness index, is the total number of sampling points on the outer wall of the metal object, is the height difference between the sampling point on the outer wall of the ith metal object and the table surface;

[0127] The gloss formula is: ,

[0128] In the formula, is the gloss index, is the intensity of the incident light of the gloss meter, It is the intensity of light reflected from the outer wall of a metal object;

[0129] The polishing effect formula is: ,

[0130] In the formula, The polishing effect of the outer wall of the metal object under each group of qualified laser parameters. They are the roughness index weight and glossiness index weight respectively.

[0131] Surface roughness is an important indicator to measure the polishing effect of the outer wall of metal objects. It reflects the size of the surface micro-geometric shape error. By calculating the change in surface roughness before and after polishing, the polishing effect can be evaluated. Surface gloss is another important indicator of the polishing effect of the outer wall of metal objects. It reflects the ability of the surface to reflect light. The higher the glossiness, the smoother the surface and the better the polishing effect.

[0132] Furthermore, the present solution also proposes a computer-readable storage medium on which a computer-readable program is stored. When the computer-readable program is called, the above-mentioned metal object outer surface polishing control method based on laser beam processing technology is executed.

[0133] It is understandable that the storage medium may be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a DVD; or a semiconductor medium, such as a solid state drive (SSD).

[0134] In summary, the advantages of the present invention are: by optimizing the laser parameters, efficient polishing of the metal surface can be achieved in a short time, significantly improving the production efficiency, removing the ups and downs on the material surface, obtaining a flatter and smoother surface morphology, and significantly improving the surface quality of the metal object. At the same time, laser polishing can also improve the hardness and wear resistance of the material surface, extend the service life of the metal object, and reduce production costs and environmental pollution.

[0135] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology, characterized in that: include: By combining numerical simulation with experimental analysis, a numerical model of the surface morphology of the outer wall of the metal object is established to simulate the changing law of the surface morphology during the polishing process. Select a Gaussian laser heat source, set laser beam parameters, and establish a numerical model of instantaneous laser state, wherein the laser beam parameters include amplitude, lateral variance, longitudinal variance, laser wavelength, laser power, scanning speed, and pulse width; The laser beam acts on the outer wall of the metal object, improving the outer wall morphology of the metal object through two methods: melting flow and vaporization removal; The temperature field distribution and surface morphology changes of the outer wall of the metal object under different laser parameters were studied by single factor experimental method. Determine whether microcracks appear on the outer wall of the metal object after polishing. If so, output that the laser parameters used for polishing the outer wall are unqualified; if not, output that the laser parameters used for polishing the outer wall are qualified; By calculating the roughness and glossiness indexes of the outer surface of the metal object, the polishing effect of the outer surface of the metal object under each combination of qualified laser parameters is evaluated; Based on the polishing effect of the outer wall of the metal object under each combination of qualified laser parameters, the optimal laser parameter configuration combination suitable for the current polishing task is output; The method of combining numerical simulation with experimental analysis to establish a numerical model of the surface morphology of the outer wall of the metal object and simulate the change law of the surface morphology during the polishing process specifically includes: Define the geometry and material properties of the numerical model of the surface morphology; For the outer wall of metal objects, geometric modeling is performed according to their actual shapes; Collect and input physical properties of the outer wall material of the metal object, wherein the physical properties include density, thermal conductivity and specific heat capacity; Divide the model based on the geometric shape and physical field distribution characteristics of the surface morphology numerical model; Conduct simulation experiments on the polishing process to simulate the heat exchange and mechanical interaction between the outer surface of the metal object and the surrounding environment during the polishing process; The reliability of the model is verified by comparing the numerical simulation results with the simulation experiment results, and the surface morphology numerical model is optimized and adjusted; The step of selecting a Gaussian laser heat source, setting laser beam parameters, and establishing a numerical model of an instantaneous laser state specifically includes: A Gaussian laser heat source is selected as the polishing laser beam; Preset Gaussian laser beam parameters; Calculate a two-dimensional Gaussian laser energy distribution function based on a preset amplitude, transverse variance, and longitudinal variance; Obtain the heat conduction equation during laser polishing; Using the heat conduction equation, calculate the temperature function value of each point in the surface morphology numerical model of the outer wall of the metal object; Based on the temperature field distribution of the outer wall of the metal object under different laser parameters, a numerical model of the instantaneous laser state is constructed and output; The two-dimensional Gaussian laser energy distribution function is: , In the formula, is the two-dimensional Gaussian laser energy distribution function, is the energy intensity amplitude of the laser center point, is the coordinate of the laser center point, are the lateral variance and longitudinal variance of the laser beam, respectively; The heat conduction equation is: , In the formula, is the density of the metal, is the specific heat capacity of metal, is the thermal conductivity of the metal, is the temperature function of each point in the numerical model of the surface morphology of the outer wall of the metal object, For time, represents the partial derivative of the temperature function with respect to time.

2. The method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology according to claim 1, characterized in that: The laser beam acts on the outer wall of the metal object, and improves the outer wall morphology of the metal object by two methods of melting flow and vaporization removal, specifically including: The Gaussian laser heat source emits a laser beam. After the material absorbs the laser energy, the surface temperature rises and is quickly transmitted into the material. When the surface temperature of the material reaches the melting threshold, the surface metal begins to melt and flow. Under the action of surface tension, the liquid metal flows and fills the valleys on the surface of the material. When the surface temperature of the material continues to rise and reaches the vaporization threshold, the surface material is removed by vaporization, and the vaporization expansion and plasma impact further affect the surface morphology of the metal material.

3. The method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology according to claim 2, characterized in that: The single factor experimental method is used to study the temperature field distribution and surface morphology changes of the outer wall of the metal object under different laser parameters, specifically including: Controlling other laser beam parameters to fixed values, changing the value of one laser beam parameter to conduct at least two laser beam polishing experiments on the outer wall of the metal object; Based on the heat conduction equation in the laser polishing process, the temperature field distribution of the outer wall of the metal object in the laser beam polishing experiment is calculated; After the laser beam polishing experiment, the outer wall of the metal object was remodeled, and the numerical models of the surface morphology before and after the experiment were compared to obtain the changes in the surface morphology.

4. The method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology according to claim 3 is characterized in that: The method of judging whether microcracks appear on the outer wall of the metal object after polishing specifically includes: S101: Use a high-power magnifying glass to directly observe the outer surface of the polished metal object along the path of the laser scan; S102: Determine whether there are fine lines or mesh structures on the outer wall of the metal object. If so, output that there are microcracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are unqualified. If not, no output is made; S103: Clean and dry the metal sample, observe the microstructure of the outer wall of the metal sample using an electron microscope, and record possible microcrack locations; S104: Subsurface damage detection of possible microcrack locations using a focused ion beam dual beam system; S105: Cutting metal samples with a focused ion beam dual-beam system and measuring the crack depth of the cross section after cutting; S106: Determine whether the crack depth is higher than the micro-crack depth threshold. If so, output that there are micro-cracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are unqualified. If not, no output is made. S107: Use a microhardness tester to test the hardness of the metal surface before and after polishing; S108: Determine whether the surface hardness of the metal after polishing is higher than that before polishing. If so, output that there are no microcracks on the outer wall of the metal object and the laser parameters used for polishing the outer wall are qualified. If not, output that there may be microcracks on the outer wall of the metal object and return to step S103.

5. The method for controlling the polishing of the outer wall of a metal object based on laser beam processing technology according to claim 4, characterized in that: The evaluation of the polishing effect of the outer wall of the metal object under each set of qualified laser parameters by calculating the roughness and glossiness index of the outer wall of the metal object specifically includes: Based on the surface morphology numerical model of the outer wall of the metal object after the polishing experiment, the height difference of each point on the outer wall of the metal object relative to the table plane is measured; Calculate the root mean square value of the height difference of each point on the outer wall of the metal object relative to the average plane, and output it as the roughness index of the outer wall of the metal object; Use a gloss meter to measure the intensity of light reflected from the outer wall of a metal object, and use the gloss formula to calculate and output its gloss index; Preset roughness index weight and glossiness index weight; The polishing effect formula is used to calculate the polishing effect of the outer wall of the metal object under each combination of qualified laser parameters; The roughness index is: , In the formula, is the roughness index, is the total number of sampling points on the outer wall of the metal object, is the height difference between the sampling point on the outer wall of the ith metal object and the table surface; The gloss formula is: , In the formula, is the gloss index, is the intensity of the incident light of the gloss meter, It is the intensity of light reflected from the outer wall of a metal object; The polishing effect formula is: , In the formula, The polishing effect of the outer wall of the metal object under each group of qualified laser parameters. They are the roughness index weight and glossiness index weight respectively.

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