Test design method for optimizing laser cladding process parameters
Through the multi-stage orthogonal experimental design method, the laser cladding process parameters are gradually optimized, which solves the limitations of the existing methods in process parameter optimization, achieves more efficient process parameter combination optimization, and improves the forming quality and performance of the cladding layer.
Patent Information
- Application Number
- CN202510173703.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-17
- Publication Date
- 2025-06-13
AI Technical Summary
The existing laser cladding process parameter optimization methods have limitations in improving performance and reducing defects, and it is difficult to accurately optimize process parameters, resulting in high test costs and low optimization accuracy.
A multi-stage experimental design method is proposed. Through multiple sets of orthogonal experimental design, the laser cladding process parameters are gradually optimized, including determining the test equipment and materials, selecting the main quality indicators and process parameter combinations, designing and carrying out multiple sets of process optimization tests, gradually narrowing the process parameter window, and obtaining the optimal process parameter combination.
More accurate laser cladding process parameter combination optimization is achieved, which reduces test costs, improves optimization accuracy, and improves the forming quality and performance of the cladding layer.
Smart Images
Figure CN120145645A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of laser cladding processing and manufacturing of metal materials, and particularly relates to an experimental design method for optimizing laser cladding process parameters. Background Art
[0002] Laser cladding technology is a new surface modification technology that emerged in the 1970s with the development of high-power lasers. By rapidly heating and melting alloy powder or ceramic powder with the substrate surface under the action of a laser beam, a surface coating with a very low dilution rate and metallurgical bonding with the substrate material is formed by self-excited cooling after the beam moves away, thereby significantly improving the surface performance of the substrate. This technology is an advanced green laser remanufacturing technology that combines high energy density concentration, high processing accuracy, a wide range of material selection, and good interfacial metallurgical bonding. It provides technical support for the problem of cladding repair of parts under high-temperature and harsh working conditions and can well solve problems such as hot processing deformation and metallurgical bonding of superalloys.
[0003] Laser cladding process parameters have a significant and direct impact on the forming quality and mechanical properties of the cladding layer. The process optimization of laser cladding technology aiming at optimizing the quality of the cladding layer has always been a research focus in the domestic and international industries. The laser cladding process is affected by various factors such as equipment, process, and environment. Among them, numerous process parameters are one of the most critical factors affecting the forming and performance of the cladding layer. The process parameters mainly include many factors such as laser power, scanning speed, spot diameter, powder feeding rate, gas flow rate, and overlapping rate. These parameters jointly affect the quality of the cladding layer and there are complex non-linear interaction effects. The quality of the cladding layer includes macroscopic forming morphology, that is, the width, height, melting depth, dilution rate, crack coefficient, and surface roughness of the cladding layer, as well as microscopic defects, tissue state, and mechanical properties of the cladding layer. Experimental and theoretical studies have shown that the cladding process parameters have a significant impact on the forming quality and mechanical properties of the cladding layer. The experimental-based method for optimizing the design of laser cladding process parameters has always been one of the research hotspots of domestic and international scholars.
[0004] The Design of Experiment (DOE) is a widely adopted experimental design method. It has been widely applied to product quality improvement and process flow optimization in industries ranging from aerospace to general manufacturing, playing a very important role throughout the entire process of product quality control. The characteristics of DOE lie in scientifically and reasonably arranging experiments, thereby reducing the number of experiments, shortening the experimental cycle, lowering experimental costs, and enhancing economic benefits. It is particularly suitable for advanced processing technologies such as laser cladding technology that have multiple process parameter factors and multiple forming quality evaluation indicators. The orthogonal experimental design method is a commonly used experimental design method in DOE. The orthogonal experimental design method is a scientific method for researching and dealing with multi-factor experiments. It uses a standardized table, namely the orthogonal table, to select experimental conditions, arrange the experimental plan, and conduct experiments. Through a relatively small number of experiments, it can find better production conditions, that is, the optimal or relatively optimal experimental plan, and it has currently been widely used in the process of optimizing laser cladding process parameters. However, due to typical characteristics such as complex laser cladding process parameters, large differences in window amplitudes, diverse optimization objectives, and different requirements, currently, the primary and secondary influencing factors and process optimization parameters obtained from a single orthogonal experiment have significant limitations. It is usually difficult to accurately achieve the optimization of laser cladding process parameters with the goals of improving performance and reducing defects. With the continuous improvement of the requirements for product quality and process accuracy, higher requirements are also put forward for the accuracy and reliability of process optimization experiments, and the difficulty of experimental design also increases accordingly. How to scientifically achieve the experimental design of laser cladding process optimization is crucial for improving the quality of the cladding layer and economic benefits.
[0005] Limited to the main problems existing in the above-mentioned experimental design process for optimizing laser cladding process parameters with the main goals of improving performance and reducing defects, it is urgent to develop an experimental design method for optimizing laser cladding process parameters to make up for the deficiencies of existing methods in terms of optimization accuracy and reliability. Based on this experimental design method, it is possible to more accurately achieve the performance improvement, morphology and defect control of the laser cladding process, provide a reliable technical approach for optimizing laser cladding process parameters, contribute to optimizing product quality and performance, and improve economic benefits. Summary of the Invention
[0006] In view of this, the present invention proposes an experimental design method for optimizing laser cladding process parameters, aiming to improve the accuracy and reliability of laser cladding process parameter optimization, optimize the morphological characteristics of the cladding layer, reduce the number of defects in the cladding layer, and improve the performance of the cladding layer. It provides technical reference for relevant practitioners to design process optimization plans and technical support for relevant enterprises to control product quality and improve performance.
[0007] The specific technical solution of the present invention is as follows:
[0008] An experimental design method for optimizing the process parameters of laser cladding. The characteristics are as follows:
[0009] S1: According to the actual manufacturing and processing and product quality requirements, determine the experimental equipment and materials, select the main quality indicators of the product during the laser cladding process as the optimization objectives, and select the main laser cladding process parameter combinations as the influencing factors;
[0010] S2: According to the selected optimization objectives and influencing factors of the laser cladding process, design and conduct the first group of process optimization experiments (DOE-1);
[0011] S3: Based on the results of the first group of process optimization experiments, obtain the optimal process parameter combination, design the second group of process test windows according to the optimal process parameter combination, and conduct the second group of process optimization experiments (DOE-2).
[0012] S4: Based on the results of the second group of process optimization experiments, obtain the optimal process parameter combination, design the third group of process test windows according to the optimal process parameter combination, and conduct the third group of process optimization experiments (DOE-3) to achieve the target optimization and obtain the optimal process parameter combination under this optimization objective.
[0013] Preferably, according to the actual manufacturing and processing and product quality requirements, determine the experimental equipment and materials, select the main quality indicators of the product during the laser cladding process as the optimization objectives, and select the main laser cladding process parameter combinations as the influencing factors. Specifically: According to the actual working conditions, determine the experimental equipment and materials. First, select the main quality evaluation indicators of the product during the laser cladding process as the process test optimization objectives, such as defect indicators such as porosity and crack density of the cladding layer, and morphological characteristics such as dilution rate and forming coefficient. Select the main process parameter combinations to be optimized as the influencing factors, such as key process parameters such as laser power, scanning speed, and powder feeding rate.
[0014] Preferably, according to the selected optimization objectives and influencing factors of the laser cladding process, design and conduct the first group of process optimization experiments (DOE-1). Specifically: After determining the main optimization objectives and influencing factors of the laser cladding process, conduct process exploration experiments. According to the macroscopic morphology state of the cladding layer, initially determine the range of the main process parameter window, change the parameters within the range of ±50% of the center of the parameter window, select the experimental scheme according to the selected process parameter combination and the orthogonal experimental table, conduct orthogonal process experiments and obtain the optimization objective results under each group of experiments.
[0015] Preferably, based on the results of the first set of process optimization tests, the optimal process parameter combination is obtained. According to the optimal process parameter combination, the second set of process test windows is designed, and the second set of process optimization tests (DOE-2) is carried out. Specifically: through the first set of orthogonal tests, the optimal process parameter combination-1 under this process window is obtained. Taking the optimal process parameter combination-1 as the center of the process parameter window, the parameters are varied within the range of ±25% of the center of the parameter window. According to the selected process parameter combination and the orthogonal test table, the test scheme is selected, and the second set of orthogonal process tests is carried out to obtain the optimized target results under each test.
[0016] Preferably, based on the results of the second set of process optimization tests, the optimal process parameter combination is obtained. According to the optimal process parameter combination, the third set of process test windows is designed, and the third set of process optimization tests (DOE-3) is carried out to achieve the target optimization and obtain the optimal process parameter combination under this optimization target. Specifically: through the second set of orthogonal tests, the optimal process parameter combination-2 under this process window is obtained. Taking the optimal process parameter combination-2 as the center of the process parameter window, the parameters are varied within the range of ±10% of the center of the parameter window. According to the selected process parameter combination and the orthogonal test table, the test scheme is selected, and the third set of orthogonal process tests is carried out to obtain the optimized target results under each test, and finally the quality target optimization and process parameter combination optimization of the laser cladding process are realized.
[0017] Compared with the prior art, the present invention has the following positive effects: The experimental design method for optimizing the process parameters of laser cladding applied in the present invention can more accurately realize the optimization of the process parameter combination based on quality improvement in the laser cladding process of metal materials, reduce the test cost required by the existing method, and improve the optimization accuracy. It helps to guide relevant enterprises and staff to optimize product performance and improve the laser cladding processing and manufacturing process. Description of the Drawings
[0018] Figure 1 Flow chart of the strategy for the experimental design method for optimizing the process parameters of laser cladding;
[0019] Figure 2 Schematic diagram of measuring the width and depth of the cladding layer;
[0020] Figure 3 Characteristic diagram of the cross-sectional morphology of the optimized cladding layer; Detailed Embodiments
[0021] The present invention will be further described below in conjunction with specific embodiments.
[0022] The following describes the present invention based on embodiments. Those of ordinary skill in the art should understand that the drawings provided here are all for the purpose of illustration, and the drawings are not necessarily drawn to scale.
[0023] An experimental design method for optimizing the process parameters of laser cladding, and its design strategy process is as shown in the appendix Figure 1 as follows
[0024] S1: According to the actual manufacturing and processing and product quality requirements, determine the test equipment and materials, select the main quality indicators of the products during the laser cladding process as the optimization objectives, and select the main laser cladding process parameter combinations as the influencing factors. The experiment uses a laser cladding system to optimize the process of nickel-based superalloy parts. The laser cladding system mainly includes a laser, a cladding head, a powder feeder, a cooling system, a KUKA robot, and a control system. Argon with a purity of 99.9% is selected as the powder feeding and protective gas. The laser beam is directed at the substrate to form a molten pool, and the powder material is continuously added in the direction of the beam to form a deposition layer. The test substrate is made of K4002 nickel-based superalloy with dimensions of 50mm * 50mm * 8mm, and IN625 nickel-based superalloy powder is selected as the filling material, with a powder particle size of 50 - 135μm. Before the experiment, the surface of the substrate is polished and cleaned to remove surface stains and oxide films. The powder is dried and placed in a vacuum drying oven at 120°C for more than 4 hours
[0025] Select the laser power, scanning speed, and powder feeding rate as the test influencing factors. Select the forming coefficient of the cladding layer as the optimization objective for the laser cladding process, and achieve an effective improvement in the forming coefficient of the cladding layer through experimental design. The forming coefficient is a parameter that comprehensively considers the width of the cladding layer and the melting depth of the substrate. Generally, the larger the forming coefficient, the better the forming quality and performance of the cladding layer. The forming coefficient is calculated according to formula (1):
[0026]
[0027] where W represents the width of the cladding layer, h represents the depth of the cladding layer, and the schematic diagram of measuring the width and depth of the cladding layer is as shown in the appendix Figure 2 as follows
[0028] S2: According to the selected optimization objectives and influencing factors of the laser cladding process, design and conduct the first group of process optimization experiments (DOE-1). After determining the main optimization objectives and influencing factors of the laser cladding process, first conduct process exploration experiments. According to the cross-sectional morphology characteristics of the cladding layer, initially determine the process parameter window range as: laser power (800W - 1600W), scanning speed (2mm / s - 10mm / s), and powder feeding rate (1r / min - 7r / min). Vary the parameters within the range of ±50% of the center of the parameter window (laser power 1200W, scanning speed 6mm / s, powder feeding rate 4r / min). According to the selected process parameter combinations and the orthogonal experimental table, select the experimental scheme as shown in Table 1, and conduct orthogonal process experiments according to Table 1 to obtain the optimization objective results for each group of experiments
[0029] Table 1 Process Parameters and Result Data of the First Group of Orthogonal Process Experiments (DOE-1)
[0030]
[0031] The range analysis method was used to analyze the experimental data obtained in Table 1, and the range analysis results in Table 2 were obtained. In the first group of orthogonal process experiments (DOE-1), the optimal process parameter combination is: laser power 1200W, scanning speed 6mm / s, powder feeding rate 4r / min.
[0032] Table 2 Range Analysis Result Data of the First Group of Orthogonal Process Experiments (DOE-1)
[0033]
[0034] S3: Based on the results of the first group of process optimization experiments, obtain the optimal process parameter combination, design the second group of process experiment windows according to the optimal process parameter combination, and conduct the second group of process optimization experiments (DOE-2). Through the first group of orthogonal experiments, obtain the optimal process parameter combination -1 under this process window, that is, laser power 1200W, scanning speed 6mm / s, powder feeding rate 4r / min. Take the optimal process parameter combination -1 as the center of the process parameter window, vary the parameters within the range of ±25% of the parameter window center, select the test plan according to the selected process parameter combination combined with the orthogonal test table, conduct the second group of orthogonal process experiments and obtain the optimization target results under each test, as shown in Table 3.
[0035] Table 3 The Second Group of Orthogonal Process Experiments (DOE-2)
[0036]
[0037] The range analysis method was used to analyze the experimental data obtained in Table 3, and the range analysis results in Table 4 were obtained. In the second group of orthogonal process experiments (DOE-2), the optimal process parameter combination is laser power 900W, scanning speed 4.5mm / s, powder feeding rate 5r / min.
[0038] Table 4 Range Analysis Result Data of the Second Group of Orthogonal Process Experiments (DOE-2)
[0039]
[0040] S4: Based on the results of the second group of process optimization tests, obtain the optimal process parameter combination. Design the third group of process test windows according to the optimal process parameter combination, conduct the third group of process optimization tests (DOE-3) to achieve the target optimization, and obtain the optimal process parameter combination under this optimization target. Through the second group of orthogonal tests, obtain the optimal process parameter combination -2 under this process window, that is, the laser power is 900W, the scanning speed is 4.5mm / s, and the powder feeding rate is 5r / min. Taking the optimal process parameter combination -2 as the center of the process parameter window, vary the parameters within the range of ±10% of the parameter window center. According to the selected process parameter combination and the orthogonal test table, select the test plan, conduct the third group of orthogonal process tests, and obtain the optimization target results under each test, as shown in Table 5.
[0041] Table 5 The third group of orthogonal process tests (DOE-3)
[0042]
[0043] Use the range analysis method to analyze the test data obtained in Table 5, and obtain the range analysis results in Table 6. In the third group of orthogonal process tests (DOE-3), the optimal process parameter combination is: the laser power is 990W, the scanning speed is 4.95mm / s, and the powder feeding rate is 5.5r / min. The cross-sectional morphology of the clad layer under this parameter is as attached Figure 3 shown. The clad layer is well formed and has no obvious crack defects. Under the process parameter combination obtained in the third optimization, the width of the clad layer is measured to be 3.24mm, the depth is 0.15mm, and the forming coefficient is 21.83. Compared with the test optimization results of the first group of orthogonal process tests (DOE-1), the forming coefficient of the clad layer has been effectively improved and optimized, verifying the effectiveness and reliability of the experimental design.
[0044] Table 6 Range analysis result data of the third group of orthogonal process tests (DOE-3)
[0045]
[0046] The analysis of the example results shows that the experimental design method for laser cladding process parameter optimization proposed by the present invention can more accurately realize the optimization of the process parameter combination based on quality improvement in the laser cladding process of metal materials through multiple groups of process optimization tests. Thus, it can effectively reduce the product defect rate, improve the product performance, and reduce the test cost required by the existing methods, and has certain guiding significance and economic value. The present invention can also provide certain reference for relevant enterprises and staff to design, evaluate and optimize the quality of laser cladding products and improve the laser cladding processing and manufacturing process.
[0047] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. An experimental design method for optimizing laser cladding process parameters, characterized in that The steps are: S1: According to the actual manufacturing and product quality requirements, determine the test equipment and materials, select the main quality indicators of the laser cladding process products as the optimization target, and select the main laser cladding process parameter combination as the influencing factor; S2: Design and carry out the first set of process optimization experiments according to the selected laser cladding process optimization objectives and influencing factors; specifically: after determining the main optimization objectives and influencing factors of the laser cladding process, carry out process exploration experiments, preliminarily determine the main process parameter window range according to the macroscopic morphology of the cladding layer, change the parameters within the range of ±50% of the center of the parameter window, select the test plan according to the selected process parameter combination combined with the orthogonal test table, carry out orthogonal process experiments and obtain the optimization target results under each set of experiments; S3: Based on the results of the first set of process optimization tests, the optimal process parameter combination is obtained, and the second set of process test windows are designed according to the optimal process parameter combination, and the second set of process optimization tests are carried out. Specifically, the optimal process parameter combination -1 under the process window is obtained through the first set of orthogonal tests, and the optimal process parameter combination -1 is used as the center of the process parameter window, and the parameters are changed within the range of ±25% of the center of the parameter window. According to the selected process parameter combination and the orthogonal test table, the test plan is selected, and the second set of orthogonal process tests are carried out to obtain the optimization target results under each set of tests; S4: Based on the results of the second group of process optimization tests, the optimal process parameter combination is obtained, and the third group of process test windows is designed according to the optimal process parameter combination. The third group of process optimization tests is carried out to achieve the optimization goal and obtain the optimal process parameter combination under the optimization goal. Specifically, the optimal process parameter combination -2 under the process window is obtained through the second group of orthogonal tests, and the optimal process parameter combination -2 is used as the center of the process parameter window. The parameters are changed within the range of ±10% of the center of the parameter window. According to the selected process parameter combination and the orthogonal test table, the test plan is selected, and the third group of orthogonal process tests are carried out to obtain the optimization target results under each group of tests, so as to finally achieve the quality target of the laser cladding process and the optimization of the process parameter combination.