A simulation method to improve the thickness uniformity of barrel coating on bolt fasteners

Abstract

The present invention discloses a simulation method for improving the uniformity of the thickness of the roll-plated film of bolt fasteners, comprising the following steps: (1) modeling: using three-dimensional mapping software to establish a three-dimensional spatial model of parts and electroplating production lines, and establishing a digital model database of electroplating production lines; (2) calculating the spatial position state of parts: using roll-plating motion simulation software to obtain the vector coordinates of parts in different time steps; (3) solving the film thickness of parts: inputting the vector coordinate data into the roll-plating film thickness simulation software, and at the same time inputting the part model, obtaining the stacking state of the parts in the drum at the end of each time step, and solving the accumulated film thickness distribution in each time step; (4) data processing. The present invention is simple and easy to implement, and can accurately and reliably predict the film thickness distribution and film thickness risk area prediction of fastener roll plating, and can find problems in advance in the design stage, reduce the verification cycle and cost, and reduce the complicated workload of process personnel.

Description

Technical Field

[0001] The invention belongs to the technical field of cadmium barrel plating on fasteners, and in particular relates to a simulation method for improving the uniformity of barrel plating film thickness on bolt fasteners. Background Art

[0002] Cadmium is a cathodic protection coating for steel substrates, but it is a sacrificial anodic protection coating under high temperature or marine climate. It does not change color in the air at room temperature, but will oxidize to form a protective film in humid air to prevent further oxidation corrosion. Cadmium oxide is insoluble in water and has strong corrosion resistance. The electroplated cadmium layer has good weldability and lubricity, low hydrogen embrittlement, good gloss and strong adhesion. It is the first choice for corrosion protection of steel fasteners used in the aerospace and marine fields, and has been widely used.

[0003] Cadmium plating of bolt fasteners is mostly processed by barrel plating due to the large number of products in a single batch. The barrel plating process, also known as the drum electroplating process, is to place a certain number of parts to be plated in a special drum and electroplate them in an indirect conductive manner in a rolling state. During the electroplating process, the parts randomly collide, roll, fall, and other movements in the drum, which makes it difficult to judge the position of the surface of the parts and the coating state. The traditional method is to continuously adjust the process and tooling, and continuously use trial plating methods at the production site to improve, summarize and improve the quality of barrel cadmium plating, and then solidify the process and experience, which requires a long process. The electroplating methods of the cadmium layer are divided into cyanide electroplating and non-cyanide electroplating. Compared with processes such as electrogalvanizing, the dispersion ability, covering ability and uniformity of the coating of the bath are poor, especially in the barrel cadmium plating process, the uniformity of the film thickness is very difficult to control. For conventional rack plating, the parts are stationary during the electroplating process and are in a stable state for metal ion deposition. Therefore, there are mature finite element analysis simulation software in the industry, and it is easy to optimize the process, tooling and equipment with the help of simulation technology. However, in the barrel plating process, the position and state of the parts are randomly distributed. The current method is difficult to comprehensively investigate and study the barrel plating process, so it is urgent to study a simulation method to improve the uniformity of the barrel plating film thickness of bolt fasteners. Summary of the invention

[0004] To solve the above problems, an object of the present invention is to provide a simulation method for improving the uniformity of the thickness of the roll-plated film on bolt fasteners.

[0005] A simulation method for improving the uniformity of the thickness of a barrel-plated film on a bolt fastener comprises the following steps:

[0006] (1) Modeling: Use 3D mapping software to build a 3D spatial model of the parts and the electroplating production line, and build a digital model database of the electroplating production line, which includes tank grid data, drum grid data, anode grid and polarization data, data on the change of current efficiency of the electroplating solution with current density, Tafel curve and other data;

[0007] (2) Calculate the spatial position state of the part: divide the roll plating process into multiple time steps, and use the roll plating motion simulation software to calculate the spatial position state of the part after continuous motion in each time step, and obtain the vector coordinates of the part at the end of each time step, so as to realize the static equivalent analysis of the dynamic process of the part during the roll plating process. The vector coordinates are 12 data including the nine angular momentum coordinates "XX, XY, XZ, YX, YY, YZ, ZX, ZY, ZZ" and the three-dimensional coordinate value "X, Y, Z" of the geometric center point of the part;

[0008] (3) Solve for the film thickness of the parts: Input the vector coordinate data obtained at each time step into the roll plating film thickness simulation software, and input the part model at the same time to obtain the stacking state of the parts in the drum at the end of each time step, and solve the accumulated film thickness distribution in each time step. Specifically, the finite element analysis method is used, with the help of theoretical foundations such as the ion migration and electrodeposition model in the solution, the Butler-Volmer Equation, and Faraday's law, to calculate the film thickness distribution of the parts in a specific placement state. The roll plating motion simulation software and the roll plating film thickness simulation software are different modules in the Elscya plating manager software;

[0009] (4) Data processing: Finally, the film thickness distribution data of each time step is obtained, and the final roll-plated film thickness distribution of the part surface is obtained through corresponding linear addition and data mapping methods. During the analysis process, changes in the process, tooling, rolling and current and voltage settings will affect the final film thickness distribution.

[0010] Compared with the prior art, the simulation method for improving the uniformity of roll-plated film thickness of bolt fasteners of the present invention has the following beneficial effects: 1. The present invention is simple and easy to implement, and can accurately and reliably predict the film thickness distribution and film thickness risk area of ​​roll-plated fasteners, and can find problems in advance in the design stage, reducing the verification cycle and cost, and reducing the complicated workload of process personnel; 2. A set of efficient methods for analyzing roll-plated fasteners is established to analyze the deficiencies of existing processes on site, including parameters such as the size of the roll-plating tank, the arrangement of the anodes and the rolling speed; 3. By using the present invention, DOE experiments of different process tools are designed to analyze and obtain the optimal film thickness distribution data, and then obtain the best film thickness uniformity solution, which helps to improve the process and optimize the quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention is further described in detail below with reference to the accompanying drawings.

[0012] Figure 1 This is a dynamic simulation calculation model diagram of cadmium barrel plating according to an embodiment of the present invention;

[0013] Figure 2 The spatial position and film thickness distribution diagram of the roll plating simulation of the parts in the embodiment of the present invention;

[0014] Figure 3 The film thickness distribution histogram before and after optimization of the embodiment of the present invention;

[0015] Figure 4 The film thickness distribution cloud diagram before and after optimization of the embodiment of the present invention;

[0016] Figure 5 The measured data of film thickness before and after optimization of the embodiments of the present invention. DETAILED DESCRIPTION

[0017] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0018] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. In addition, the term "include" or any other variant is intended to cover non-exclusive inclusion, so that a process, method, article or device containing a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Example

[0019] The simulation method of the present invention can be applied to the barrel cadmium plating process of fasteners, and is also applicable to other barrel plating processes. The specific implementation of the present invention is described below using the barrel cadmium plating process.

[0020] A simulation method for improving the uniformity of the thickness of a barrel-plated film on a bolt fastener comprises the following steps:

[0021] (1) Modeling: Use 3D graphics software to build a 3D spatial model of parts and electroplating production lines, such as Figure 1As shown, a digital model database of an electroplating production line is established, wherein the digital model database of an electroplating production line includes data such as tank grid data, drum grid data, grid and polarization data of an anode, data on changes in current efficiency of an electroplating solution with current density, and Tafel curves;

[0022] (2) Calculate the spatial position state of the part: divide the roll plating process into multiple time steps, and use the roll plating motion simulation software to calculate the spatial position state of the part after continuous motion in each time step, and obtain the vector coordinates of the part at the end of each time step, so as to realize the static equivalent analysis of the dynamic process of the part during the roll plating process. The vector coordinates are 12 data including the nine angular momentum coordinates "XX, XY, XZ, YX, YY, YZ, ZX, ZY, ZZ" and the three-dimensional coordinate value "X, Y, Z" of the geometric center point of the part;

[0023] (3) Solve for the film thickness of the parts: Input the vector coordinate data obtained at each time step into the roller coating film thickness simulation software, and input the part model at the same time to obtain the stacking state of the parts in the roller at the end of each time step, and solve the cumulative film thickness distribution in each time step, such as Figure 2 As shown, specifically, the finite element analysis method is used, with the help of the theoretical basis such as the ion migration and electrodeposition model in the solution, the Butler-Volmer Equation and the Faraday's law, to calculate the film thickness distribution of the parts under a specific placement state. The roller plating motion simulation software and the roller plating film thickness simulation software are different modules in the Elscya plating manager software;

[0024] (4) Data processing: Finally, the film thickness distribution data of each time step is obtained, and the final roll-plated film thickness distribution of the part surface is obtained through corresponding linear addition and data mapping methods. During the analysis process, changes in the process, tooling, rolling and current and voltage settings will affect the final film thickness distribution.

[0025] During the specific operation process, the roller plating tank body, tank liquid, anode material, anode size and shape, and roller plating process can be comprehensively considered, including the influence of process parameter settings such as roller speed, loading capacity, current, voltage, and time on the thickness of the roller plating cadmium film, helping to analyze and optimize the process parameters and condition settings of roller cadmium plating.

[0026] The simulation method of the present invention is used to analyze the distribution bar graph and the distribution cloud graph of the barrel-plated cadmium film thickness before and after optimization using a certain type of bolt. Figure 3 , 4 As shown in Figure 2, the uniformity of the film thickness is significantly improved after optimization, and the difference in film thickness between the end and the middle of the part is reduced. The measured film thickness data before and after optimization are shown in Figure 2. Figure 5 shown.

[0027] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific implementation methods. Any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A simulation method for improving the uniformity of the thickness of the barrel-plated film on bolt fasteners, characterized in that : It includes the following steps: (1) Modeling: Use 3D mapping software to build a 3D spatial model of parts and electroplating production lines, and establish a digital model database for electroplating production lines; (2) Calculate the spatial position of the part: Use the roller plating motion simulation software to calculate the vector coordinates of the part in different time steps. The vector coordinates include the angular momentum coordinates of "XX, XY, XZ, YX, YY, YZ, ZX, ZY, ZZ" and the three-dimensional coordinate values ​​of the geometric center point of the part "X, Y, Z"; (3) Determine the film thickness of the parts: Input the vector coordinate data into the roller coating thickness simulation software, and input the part model at the same time to obtain the stacking state of the parts in the roller at the end of each time step, and calculate the cumulative film thickness distribution in each time step; (4) Data processing: Finally, the final distribution of coating thickness on the surface of the part is obtained through data processing.

2. The simulation method for improving the uniformity of the thickness of the barrel-plated film of bolt fasteners according to claim 1, characterized in that The digital model database of the electroplating production line includes tank grid data, drum grid data, anode grid and polarization data, data on the change of current efficiency of the electroplating solution with current density, and Tafel curve.

3. The simulation method for improving the thickness uniformity of the barrel-plated film of bolt fasteners according to claim 1 or 2, characterized in that : When calculating the spatial position state of the part, the roll plating process is divided into multiple time steps, and the spatial position state of the part after continuous movement in each time step is calculated to obtain the vector coordinates of the part at the end of each time step.

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