Process parameter optimization method and system for suppressing spatter in spot ring light spot laser welding

Abstract

The invention belongs to the field of new energy automobile power batteries and the related field of laser welding, and discloses a technological parameter optimization method and system for spot ring light spot laser welding spatter suppression, and the method comprises the steps that the relation between the preheating temperature of an outer ring light beam to a weld joint and welding technological parameters is obtained; establishing optimization constraint conditions of the preheating temperature, and deducing optimization constraint conditions of process parameters; acquiring a preset range of the process parameters; and substituting the technological parameter values in the preset range into optimization constraint conditions of the technological parameters, and combining the technological parameters meeting the preheating temperature into optimized technological parameters. According to the method, by optimizing the preheating temperature of the annular light beam to the welding seam, regulation and control are directly carried out according to key factors for forming spatter, and generation of spatter is effectively restrained; by optimizing technological parameters, the stability of the welding process is improved, and therefore welding defects are reduced.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the field of new energy vehicle power batteries and laser welding related technical fields, and in particular relates to a process parameter optimization method and system for spatter suppression in spot ring spot laser welding. Background Art

[0002] Laser welding technology has the characteristics of high energy density, low heat input and good flexibility and is widely used in new energy vehicles, power batteries, aerospace and marine equipment industries. However, the extremely high energy density of laser (up to 10 8 W / cm2) causes the weld metal to evaporate abnormally violently; under the strong recoil pressure of the metal vapor, the molten metal in the molten pool is pushed away instantly to form a slender keyhole; the molten metal fluctuates violently, and it is easy to form a liquid column at the opening of the small hole; the steam shear force generated when the high-temperature (up to 6000K) and high-speed (up to 500m / s) metal vapor passes through the slender small hole can easily cause the molten metal at the top of the liquid column to separate and form splashes. The large amount of spatter formation will reduce the molten metal, resulting in welding defects such as unfilled and undercut in the weld; in addition, spatter will contaminate the workpiece, and removing the spatter requires additional processes, increasing manufacturing costs and reducing production efficiency.

[0003] In recent years, spot ring spot laser welding has been proposed as an emerging technology, which has attracted widespread attention from inventors at home and abroad. The core idea of ​​spot ring spot laser welding is to introduce a ring spot laser beam on the basis of laser (Gaussian spot) welding to regulate the spatial distribution of laser energy. The invention shows that the spot ring spot laser welding technology can expand the keyhole opening, uniform temperature gradient, effectively reduce spatter and improve weld formation. However, this type of laser is relatively new and has a weak invention foundation. Although there have been a few reports on improving spatter, a systematic spatter improvement plan has not yet been formed.

[0004] In view of the above analysis, the technical problems that need to be solved urgently in the prior art are:

[0005] (1) During the laser welding process, the extremely high energy density causes the metal to evaporate extremely violently, the welding process is unstable, and the violent fluctuations of the molten pool can easily cause spatter defects.

[0006] (2) Traditional Gaussian beams have limitations in regulating energy distribution. During Gaussian laser welding, the energy is mainly concentrated in the center of the beam, resulting in a large thermal gradient, which can easily cause instability in the welding process.

[0007] (3) The existing shaped laser beam technology is relatively new and has a weak invention basis for application in the field of welding. Although there have been a few reports on improving spatter, a systematic spatter improvement solution has not yet been formed. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a process parameter optimization method and system for spatter suppression in spot ring spot laser welding.

[0009] The present invention is implemented as follows: a method for optimizing process parameters for suppressing spatter in spot ring laser welding, characterized in that the method for optimizing process parameters for suppressing spatter in spot ring laser welding specifically comprises:

[0010] S1: Obtain the relationship between the preheating temperature of the outer ring beam on the weld and the welding process parameters;

[0011] S2: Establishing the optimization constraint conditions of the preheating temperature and deriving the optimization constraint conditions of the process parameters; obtaining the preset range of the process parameters;

[0012] S3: Substituting the process parameter values ​​within the preset range into the optimization constraints of the process parameters, and combining the process parameters that satisfy the constraints into optimized process parameters.

[0013] Furthermore, the process parameters include total laser power, ring power ratio, and welding speed.

[0014] The heat required to heat an object can be calculated as follows:

[0015] Q=cm(T-T0) (1)

[0016] Among them, Q(J) is the heat that the object needs to absorb to raise its temperature, c(J / kg*K) is the specific heat capacity, m(kg) is the mass, T(K) and T0(K) are the heating temperature and initial temperature respectively.

[0017] The relationship between the preheating temperature of the ring beam on the weld and the process parameters is:

[0018]

[0019] or

[0020]

[0021] P total (W) is the total laser power, R ring is the ring power ratio, A front (m 2 ) Ring beam front end preheating area, A ring (m 2 ) is the total area of ​​the ring, k is the absorption rate of the solid aluminum alloy to the laser, d ring (mm) is the ring width, v (mm / s) is the welding speed, ρ (kg / m 3 ) is the material density, s(m) is the preheated thickness. Therefore, the following formula can be derived:

[0022]

[0023] The optimization constraints of the temperature are:

[0024]

[0025] That is, the optimization constraints of the process parameters are:

[0026]

[0027] Furthermore, the preset range of the process parameters is obtained according to the working range of each parameter of the welding system or the process requirements.

[0028] Further, the process parameter values ​​are input into the optimization constraints, and when the process parameter values ​​satisfy the optimization constraints, they are retained; otherwise, they are discarded and the next set of process parameter verification is performed.

[0029] Another object of the present invention is to provide a system for optimizing process parameters for spatter suppression in spot ring spot laser welding based on the method for optimizing process parameters for spatter suppression in spot ring spot laser welding. The system for optimizing process parameters for spatter suppression in spot ring spot laser welding comprises:

[0030] A parameter acquisition module is used to obtain the relationship between the preheating temperature of the outer ring beam on the weld and the welding process parameters;

[0031] A condition establishment module, used to establish the optimization constraint conditions of the preheating temperature and derive the optimization constraint conditions of the process parameters; used to obtain the preset range of the process parameters;

[0032] The condition optimization module substitutes the process parameter values ​​within the preset range into the optimization constraint conditions of the process parameters, and the process parameters are combined into the optimized process parameters.

[0033] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0034] First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving the problems, the technical solutions to be protected by the present invention and the results and data during the research and development process are closely combined to analyze in detail and deeply how the technical solutions of the present invention solve the technical problems, and some creative technical effects brought about after solving the problems. The specific description is as follows:

[0035] Significant spatter suppression effect: The present invention significantly reduces spatter defects in the welding process by optimizing process parameters, thereby improving the quality and reliability of the welded joint. Starting from the preheating degree of the ring beam on the weld, the present invention uses the preheating temperature of the ring spot laser on the weld as an indicator to characterize spatter, and establishes a correlation between the preheating temperature and the process parameters to be optimized. The constraints on the process parameters are realized by the constraints on the preheating temperature, and then multiple sets of better process parameters are obtained, which can be directly used in engineering applications to achieve precise control of welding parameters and ultimately achieve less / no spatter welding. Spot ring spot laser welding is different from single laser welding. The addition of a ring beam can effectively adjust the spatial energy distribution of the laser to achieve the effect of preheating the front end of the weld; and the reduction of the temperature gradient helps to reduce the surface tension gradient, which is conducive to the smooth flow of the fluid and is not conducive to the formation of a liquid column; at the same time, the spot ring laser shows advantages in expanding the keyhole opening and reducing the collapse of the keyhole, which is conducive to the smooth escape of metal vapor, reducing the vapor shear force, and further spatter is suppressed.

[0036] Improved welding efficiency: By precisely controlling process parameters, the present invention not only improves welding quality but also helps to improve welding efficiency.

[0037] Wide applicability: The optimization steps and standardized measurement methods of this method make it widely applicable to the welding of different types of materials, and it has strong practicality and universality. The present invention does not require a large number of process tests to obtain process parameters with less spatter, and can be used to optimize process parameters. The operation is simple and the process design cycle is significantly shortened.

[0038] Systematization of process parameter optimization: The present invention provides a systematic process parameter optimization method, which can be adjusted and optimized according to specific application requirements, providing a more flexible and efficient welding process selection. Without the need for complex external tooling, the spatter problem caused by high-speed laser welding can be significantly improved by flexibly adjusting the power ratio of the center point Gaussian beam and the outer ring beam, which can provide a reference for high-quality laser welding.

[0039] Second, the technical solution of the present invention includes a set of systematic spatter improvement solutions during laser welding, which effectively improves the prominent problem of spatter defects in laser welding and fills the invention gap of spatter system improvement solutions in spot ring spot laser welding.

[0040] Third, the technical solution of the present invention solves the problem of spatter generated during laser welding in the prior art, especially in the welding process of aluminum alloy materials, where spatter not only affects the quality of the weld, but also damages the surrounding equipment and working environment. It is difficult to effectively suppress the spatter phenomenon through traditional welding parameter adjustment in the prior art, especially on materials with high reflectivity and high thermal conductivity such as aluminum alloy.

[0041] Technical issues: The existing laser welding process is prone to spatter during the welding of highly reflective materials (such as aluminum alloys), which affects the quality of weld formation and has low welding efficiency. It is difficult to accurately control the temperature distribution of the welding area by adjusting traditional process parameters, which is prone to cause weld surface defects and spatter.

[0042] Significant technological advancements:

[0043] 1. Significant spatter suppression effect: The present invention significantly reduces spatter defects in the aluminum alloy welding process by optimizing process parameters, thereby improving the quality and reliability of the welded joint.

[0044] 2. Accurate control of process parameters: By establishing the optimization constraints of process parameters, the total laser power, ring power ratio, welding speed and other parameters are accurately adjusted to ensure the stability and repeatability of the process. This precise control improves the quality of the weld, avoids spatter, and reduces the cost of secondary processing in the later stage.

[0045] 3. Wide applicability: The present invention is not only suitable for the welding of aluminum alloy materials, but can also be applied to other metal materials with high reflectivity or high thermal conductivity, such as copper, magnesium alloy, etc., and has broad industrial application prospects.

[0046] Through the technical solution of the present invention, the welding process is more stable, spatter is significantly reduced, and the quality of the weld is significantly improved, thereby achieving a dual improvement in welding efficiency and quality. It is particularly suitable for high-precision manufacturing fields such as aviation, automobiles, and electronics.

[0047] Fourth, the present invention solves the problem of optimizing laser welding process parameters in the prior art by introducing a mathematical model. In particular, in the welding process of highly reflective materials such as aluminum alloys, it is difficult for traditional processes to effectively suppress spatter, resulting in unstable welding quality. In the prior art, the adjustment of welding parameters usually relies on experience and lacks scientific quantitative means, making it difficult to achieve precise control of the temperature distribution in the welding area, thereby causing spatter, uneven welds and other problems.

[0048] Existing technical problems solved:

[0049] 1. Spatter is difficult to suppress during welding: Traditional welding processes cannot effectively control the welding temperature distribution, especially on high thermal conductivity materials such as aluminum alloys. A large amount of spatter will be generated during welding, affecting the weld formation and reducing the welding efficiency.

[0050] 2. Difficulty in optimizing process parameters: In the existing laser welding technology, there is a lack of a unified mathematical model to quantify the relationship between preheating temperature and process parameters (such as laser power, welding speed, ring power ratio, etc.), resulting in parameter adjustment mainly relying on experience, making it difficult to accurately control welding quality.

[0051] Mathematical model solution:

[0052] The present invention solves the above problem by establishing a mathematical model between the preheating temperature and welding process parameters of spot ring spot laser welding. The model combines the welding parameters with the physical heat transfer process, quantifies the preheating temperature of the front end of the ring-to-weld seam during the welding process, and thus realizes the precise optimization of the process parameters.

[0053] 1. Relationship model between preheating temperature and process parameters:

[0054] The present invention establishes the relationship between the preheating temperature and the total laser power, the ring power ratio, the welding speed and the physical property parameters of the material through formulas (2), (3) and (4).

[0055] By optimizing the constraint conditions (Formulas (5) and (6)), the process parameter combination that meets the preheating temperature requirements is accurately calculated to ensure that the preheating temperature of the front end of the ring-to-weld joint during the welding process is controlled within the optimal range for spatter suppression.

[0056] 2. Precise control of process parameters:

[0057] By using this mathematical model, the best combination of process parameters can be calculated through simulation during the process design stage, thereby reducing on-site debugging time and lowering production costs.

[0058] By optimizing parameters such as laser power, welding speed, and ring power ratio, preheating of the front end of the weld is achieved, reducing spatter caused by the sudden increase in laser absorption rate after the aluminum alloy reaches the melting point, and improving the weld quality.

[0059] Significant technological advancements:

[0060] 1. Accurately control the preheating temperature and reduce spatter: By optimizing the welding parameters through the model, the preheating temperature can be accurately controlled, which significantly reduces the welding spatter phenomenon and improves the stability and quality of welding.

[0061] 2. Improve welding efficiency and quality: The present invention realizes scientific optimization of process parameters through mathematical models, reduces dependence on experience-based parameter adjustment, ensures the repeatability and consistency of the welding process, significantly improves weld quality, and meets the requirements of high-precision manufacturing.

[0062] 3. Wide applicability: This mathematical model is not only suitable for the welding of aluminum alloy materials, but can also be applied to other high-reflectivity, high-thermal conductivity materials such as copper and magnesium alloys, etc., to achieve the optimization of welding processes for different materials and has broad industrial application prospects.

[0063] Through the mathematical model of the present invention, the optimization of laser welding process parameters is more scientific and accurate, the welding process is more stable, the problems of spatter suppression and process parameter optimization in the prior art are solved, and the welding efficiency and quality are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a flow chart of a process parameter optimization method for spatter suppression of spot ring spot laser welding provided by an embodiment of the present invention;

[0065] Figure 2 Schematic diagram of spot ring spot laser welding provided by an embodiment of the present invention;

[0066] Figure 3 It is a schematic diagram of the preheating effect of the annular laser on the workpiece to be welded and the definition of related parameters provided by an embodiment of the present invention;

[0067] Figure 4 It is a specific flow chart of a process parameter optimization method for spatter suppression in spot ring spot laser welding provided by an embodiment of the present invention;

[0068] Figure 5 1. It is a schematic diagram of the structure of a system for optimizing process parameters for spatter suppression in spot ring spot laser welding provided by an embodiment of the present invention;

[0069] Figure 6 It is a welding defect diagram in the spot ring spot laser welding provided by an embodiment of the present invention;

[0070] Fig. 7A It is a schematic diagram of the pure Gaussian spot laser welding process parameters after welding provided by an embodiment of the present invention;

[0071] Figure 7B It is a schematic diagram of welding under the combination of process parameters b of a common design provided by an embodiment of the present invention;

[0072] Figure 7C It is a schematic diagram of welding under the optimized process parameter c combination provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0074] Example 1: Laser welding of aluminum alloy structural parts

[0075] In the field of new energy vehicle power batteries, the welding of aluminum alloy structural parts is a key process. In order to reduce the spatter generated during welding and improve the welding quality, the spot ring laser welding technology is used, and the spatter phenomenon is suppressed by optimizing the process parameters.

[0076] Material: Aluminum alloy sheet (such as Al 1060) with a thickness of 1mm.

[0077] Process parameters:

[0078] The total laser power is 3000W;

[0079] The ring power accounts for 40%;

[0080] The welding speed is 200mm / s.

[0081] According to the physical properties of 1060 aluminum alloy, the preheating temperature range of the ring beam weld is 600K~2460K. According to the above formulas (2), (3), (4), (5), (7), P is calculated. total R ring / v constraint. By adjusting the process parameter combination, the temperature of the aluminum alloy is controlled within the range to avoid splashing.

[0082] The optimized process parameters effectively reduce spatter, stabilize the weld quality, and meet the high requirements for welding efficiency and quality in automobile manufacturing, and are particularly suitable for automated welding production lines.

[0083] This embodiment demonstrates the successful application of the present invention in aluminum alloy welding. By optimizing the process parameters of spot ring spot laser welding, the spatter suppression effect is achieved, and the quality and efficiency of welding are guaranteed. It is suitable for multiple industrial fields such as new energy vehicle power batteries.

[0084] like Figure 1-Figure 4 As shown, an embodiment of the present invention provides a method for optimizing process parameters for spatter suppression in spot ring laser welding, the method specifically comprising:

[0085] S1, obtaining the relationship between the preheating temperature of the outer ring beam on the weld and the welding process parameters;

[0086] S2, establishing the optimization constraint conditions of the preheating temperature, and deriving the optimization constraint conditions of the process parameters; obtaining the preset range of the process parameters;

[0087] S3, substituting the process parameter values ​​within the preset range into the optimization constraint conditions, and then combining the process parameters that meet the preheating temperature into the optimized process parameters.

[0088] The process parameter optimization method for spatter suppression of spot ring spot laser welding provided by the embodiment of the present invention mainly achieves the purpose of effectively suppressing spatter by analyzing and optimizing the relationship between the preheating temperature of the outer ring beam and the welding process parameters during the welding process. Its detailed working principle is divided into the following steps:

[0089] Step S1: Obtain the relationship between the preheating temperature of the outer ring beam on the weld and the welding process parameters

[0090] First, the preheating temperature of the weld seam under different process parameters (such as laser power, spot size, welding speed, etc.) is measured by experiments or simulations. The preheating temperature of the outer ring beam will directly affect the heat distribution of the weld seam and the degree of melting of the material, thereby affecting the change in the absorption rate of the aluminum alloy to the laser and ultimately the spatter phenomenon during the welding process. Through experiments with different combinations of process parameters, a functional relationship model between the preheating temperature and process parameters is established. These parameters include but are not limited to laser power, welding speed, spot diameter, etc.

[0091] Step S2: Establish the optimization constraint conditions of the preheating temperature and derive the optimization constraint conditions of the process parameters

[0092] Next, according to the melting point and boiling point of the material to be welded, set the optimization constraint conditions of the preheating temperature. The optimization goal is to control the preheating temperature of the outer ring beam to the front end of the weld above the melting point and below the boiling point while ensuring the quality of the weld. This not only avoids the molten pool oscillation caused by the jump in laser absorption rate when the aluminum alloy temperature reaches the melting point, but also avoids the instability caused by the formation of small holes after the aluminum alloy is heated to the boiling point. The core of this step is to set reasonable constraints and derive the optimization constraints of the process parameters, so that the subsequent optimization parameters can be optimized in accordance with the actual welding requirements.

[0093] Step S3: Obtaining the preset range of process parameters

[0094] In this step, preset ranges for welding process parameters are determined. These preset ranges are defined based on the welding equipment hardware, capabilities, material properties, and process requirements. The preset ranges are the basis for calculations and analysis in the subsequent optimization process.

[0095] Step S4: Substitute the optimization constraints of process parameters

[0096] Substitute the preset range of process parameters obtained in step S3 into the process parameter optimization constraint conditions set in step S2, and analyze through mathematical calculation whether these process parameter combinations can meet the preset temperature optimization constraint conditions. Through substitution and calculation, a series of process parameter combinations that meet the constraint conditions can be obtained.

[0097] Step S5: Screening the optimized process parameter combination

[0098] After calculation, multiple process parameter combinations that meet the constraints will be screened out. In this step, the optimal process parameter combination can be selected according to different priorities, such as a parameter combination that can effectively control spatter and improve welding speed and efficiency. At the same time, by comparing the preheating temperatures of different combinations, further optimization can be performed to select the best welding process parameters.

[0099] Step S6: Apply the optimized process parameters for welding

[0100] Finally, the optimized process parameter combination is used for actual welding operation. In practice, by controlling the preheating temperature of the outer ring beam, the preheating temperature of the outer ring beam on the front end of the weld is controlled above the melting point and below the boiling point. This not only avoids the molten pool oscillation caused by the jump in the laser absorption rate of the aluminum alloy at the melting point, but also avoids the instability caused by the formation of small holes after the aluminum alloy is heated to the boiling point, thereby effectively suppressing the generation of spatter and improving the welding quality and efficiency.

[0101] Through this optimization method, various parameters in the welding process can be accurately adjusted, making the welding process more stable and controllable, reducing welding spatter and improving the overall quality of the weld.

[0102] The process parameters include laser power, welding speed, and spot-ring laser power ratio.

[0103] In the embodiment of the present invention, the basic physical equation (7) for the heat absorption of a reference object is:

[0104] Q=cm(T-T0) (7)

[0105] Among them, Q(J) is the heat that needs to be absorbed, c(J / kg*K) is the specific heat capacity, m(kg) is the mass, T(K) and T0(K) are the heating temperature and initial temperature respectively.

[0106] The relationship between preheating temperature and welding process parameters is as follows:

[0107]

[0108] or

[0109]

[0110] P total (W) is the total laser power, R ring is the ring power ratio, A front (m 2 ) Ring beam front end preheating area, A ring (m 2) is the total area of ​​the ring, kk is the absorption rate of the solid aluminum alloy to the laser, d ring (mm) is the ring width, v (mm / s) is the welding speed, ρ (kg / m 3 ) is the material density, s(m) is the preheated thickness.

[0111] Therefore, the following formula can be derived:

[0112]

[0113] The optimization constraints of the temperature are:

[0114]

[0115] That is, the optimization constraints of the process parameters are:

[0116]

[0117] like Figure 5 As shown, an embodiment of the present invention provides a spatter suppression process parameter optimization system in spot ring spot laser welding, which specifically includes:

[0118] A parameter acquisition module is used to obtain the relationship between the preheating temperature of the outer ring beam on the weld and the welding process parameters;

[0119] A condition establishment module, used to establish the optimization constraint conditions of the preheating temperature and derive the optimization constraint conditions of the process parameters; used to obtain the preset range of the process parameters;

[0120] The condition optimization module substitutes the process parameter values ​​within the preset range into the optimization constraint conditions, and the process parameter combination that satisfies the preheating temperature is the optimized process parameter. The spatter suppression process parameter optimization system in the spot ring spot laser welding provided by the embodiment of the present invention realizes the optimization of the process parameters for suppressing spatter during the welding process through the synergistic effect of three modules. The following is the detailed working principle of the system:

[0121] 1. Parameter acquisition and analysis

[0122] First, the system collects the relationship between the preheating temperature of the weld seam and the welding process parameters during the welding process through the parameter acquisition module. The preheating effect of the outer ring beam directly affects the temperature distribution of the weld seam, thereby indirectly affecting the spatter phenomenon. Therefore, by collecting the changes in preheating temperature with different process parameters (such as laser power, welding speed, etc.), it can provide the necessary basic data for subsequent process parameter optimization.

[0123] 2. Establishment of optimization constraints

[0124] After obtaining the relationship between the preheating temperature and the process parameters, the condition establishment module further analyzes the conditions for the occurrence of the spatter phenomenon, and uses this as a basis to establish the optimization constraints of the preheating temperature. By deriving the preheating temperature range that meets the spatter suppression requirements, the module also derives the optimization constraints of the process parameters. In addition, the module obtains the preset range of each process parameter to ensure that the optimization result is within the controllable range of the actual welding process, providing reasonable boundary conditions for the system optimization process.

[0125] 3. Parameter combination optimization

[0126] The condition optimization module receives and applies the established optimization constraints to screen different process parameter combinations within the preset range. Specifically, the module substitutes each process parameter value into the optimization constraint of the preheating temperature to confirm whether it meets the spatter suppression requirements. Only when the process parameter combination meets the preheating temperature requirements will it be considered as the optimized process parameter output to ensure effective spatter suppression during the welding process.

[0127] 4. Output optimization results and application feedback

[0128] The system finally outputs a combination of process parameters that meets the optimization constraints and applies it to the welding process. Through actual application tests of these optimized process parameters, their effect on spatter suppression can be verified, and the parameter optimization results can be adjusted and improved through a feedback mechanism. This closed-loop optimization process enables the system to gradually improve welding quality and provide more accurate data support for spatter suppression in subsequent welding processes.

[0129] The welding defects in the spot ring laser welding are shown in the figure Figure 6 shown.

[0130] In the present invention, it is known that the physical property parameters of 6061 aluminum alloy are c=1050J / kg*K, ρ=2660kg / m3, the laser parameters are outer ring diameter 0.87mm, inner ring diameter 0.34mm, ring width d=0.265mm, k=5%, and the empirical value of the preheating thickness s is 0.5mm according to the experimental results. Therefore, the following constraints can be derived:

[0131] 31.9≤P Total R ring v≤131 (13)

[0132] The preset range of the process parameters can be obtained. Specifically, the range of the process parameters can be roughly selected according to the reachable range of the welding equipment or the range required in the actual operation process. In this way, the variation range of the point laser power can be roughly obtained as [P min , P max ], welding speed variation range is [vmin , v max ], the change range of ring power ratio is [R min , R max ].

[0133] The points in the above variation interval are gradually substituted into the above optimization constraints by interpolation. The parameter combination that meets the above constraints is retained. Otherwise, the group of parameters is discarded and the verification calculation of the next group of parameters is performed. In this way, a better combination of process parameters can be screened out from the above rough selection range, and the optimal process parameters can be directly selected next time they are used. It is simple and convenient.

[0134] A set of parameters of pure Gaussian spot laser welding experimental design was randomly selected, for example, parameter a: power 4500W, welding speed 40mm / s, ring power ratio 10:0. A set of parameters of ordinary experimental design was randomly selected, parameter b: power 5500W, welding speed 40mm / s, ring power ratio 20%; a set of optimized experimental design parameters was selected according to the present invention, parameter c: power 5900W, welding speed 40mm / s, ring power ratio 60%; welding tests were carried out respectively, and the weld surface formation was as follows Figures 7A to 7C The experimental results show that the spatter of the weld with the process parameters optimized by this method is significantly less than that of the process parameters designed by ordinary experiments.

[0135] The above method steps only list the process of designing process parameters corresponding to the low / no-splash welding of 6061 aluminum alloy. In fact, the method of the present invention is also applicable to process design under other materials, such as when the welding base material is steel.

[0136] In summary, the present invention starts from the preheating degree of the ring beam on the weld, uses the preheating temperature as a correlation index to characterize spatter, takes the preheating degree as a spatter evaluation index, and establishes a relationship between the preheating temperature and the process parameters to be optimized. By controlling the constraint conditions of the preheating temperature, the constraints of the process parameters are realized, and then multiple groups of better process parameters are obtained, which can be directly used in engineering applications to achieve precise control of the process parameters, ultimately achieving less spatter welding, and significantly improving the welding quality and efficiency.

[0137] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0138] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A process parameter optimization method for spatter suppression in spot ring laser welding, characterized in that: The method specifically includes: S1: Obtain the relationship between the preheating temperature of the outer ring beam on the weld and the welding process parameters; S2: establishing the optimization constraint conditions of the preheating temperature, and deriving the optimization constraint conditions of the process parameters, and obtaining the preset range of the process parameters; S3: Substituting the process parameter values ​​within the preset range into the optimization constraint conditions of the process parameters, the process parameter combination that satisfies the preheating temperature is the optimized process parameter.

2. The process parameter optimization method for spatter suppression of spot ring laser welding according to claim 1, characterized in that: The process parameters include total laser power, ring power ratio, and welding speed. The heat required to be absorbed by the known object to heat up can be calculated as follows: Q=cm(T-T0) (1) Among them, Q(J) is the heat that needs to be absorbed, c(J / kg*K) is the specific heat capacity, m(kg) is the mass, T(K) and T0(K) are the heating temperature and initial temperature respectively. The relationship between the preheating temperature of the ring beam on the weld and the process parameters is: or P total (W) is the total laser power, R ring is the ring power ratio, A front (m 2 ) Ring beam front end preheating area, A ring (m 2 ) is the total area of ​​the ring, kk is the absorption rate of the solid aluminum alloy to the laser, d ring (mm) is the ring width, v (mm / s) is the welding speed, ρ (kg / m 3 ) is the material density, s(m) is the preheated thickness. Therefore, the following formula can be derived: The optimization constraints of the temperature are: That is, the optimization constraints of the process parameters are:

3. The process parameter optimization method for spatter suppression of spot ring laser welding according to claim 1, characterized in that: The preset range of the process parameters is obtained according to the working range of each parameter of the welding system or the process requirements.

4. The process parameter optimization method for spatter suppression of spot ring laser welding according to claim 1, characterized in that: The process parameter values ​​are input into the optimization constraints. When the process parameter values ​​satisfy the optimization constraints, they are retained; otherwise, they are discarded and the next set of process parameter verification is performed.

5. A spatter suppression process parameter optimization system in the spot ring spot laser welding according to claims 1-4, characterized in that: The system specifically includes: A data acquisition module is used to obtain the relationship between the preheating temperature of the outer ring beam on the weld and the welding process parameters; The constraint condition establishment module is used to set the optimization constraint conditions of the preheating temperature according to the welding requirements and derive the optimization constraint conditions of the process parameters; The parameter optimization module is used to substitute the preset range of the process parameters into the optimization constraints and generate a process parameter combination that satisfies the preheating temperature as the optimized process parameters.

6. The system according to claim 5, characterized in that The data acquisition module is further used to obtain welding process parameters such as laser power, welding speed, spot diameter, etc., and establish a relationship model between these process parameters and the preheating temperature of the outer ring beam through experiments or simulations.

7. The system according to claim 5, characterized in that The parameter optimization module analyzes the process parameter combination by simulation or numerical calculation, and selects the optimal process parameter combination that meets the preheating temperature optimization constraint condition, which is used in actual welding operation to suppress welding spatter and improve weld quality.

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