process automatization for the manufacturing of coatings on complex geometries by thermal spraying.

by:ZHENHUA     2020-09-01
Abstract: In order to combine the properties of the substrate and coating materials, the thermal spraying process allows the application of various metallurgical, ceramic and ceramic coatings abroad.
To ensure the quality and network needed to be achieved,
The automated robot-assisted manufacturing and control system must realize the Shape Properties of the coating and the reproduction of the production process.
The trajectory of the torch has an important impact on the heat transfer during the coating process.
By using the proper trajectory and velocity distribution of the torch, the structure and final performance of the coating can be improved.
Key words: automation, robot, spraying, coating manufacturing1.
Introduction in the quality control of thermal spraying process, reproduction is still a problem.
This is especially the case if the specific requirements of the thermal spray coating are lower in tolerance related to the coating structure, hardness, thickness, roughness and pores.
The interaction between the trajectory and speed of the robot must be optimized and automatically manipulated to locate the coordinates and coating parameters, such as fuel flow and powder feed rate, to improve repeatability, and obtain high quality and costeff coating with narrow dimensional tolerance, best surface performance
Making a coating on complex geometry requires generating an optimized trajectory in order to maintain a constant spray distance in the defined torch speed. 2.
Analysis of coating manufacturing process 2.
1 Internal HVOF series coating process for cylinder holes in light engine manufacturing in order to improve system efficiency and reduce fuel consumption and pollution emission levels and reduce the convenience of total vehicle weight, the utilization rate of light metal components for engine applications is continuously increasing.
However, the poor surface properties of light metals, especially the poor wear and friction properties, usually inhibit the industrial application of light metals.
For this reason, and due to the operating conditions of the high load, the surface of the gas cylinder must be reinforced.
By using a thermal spray coating, the reinforcement of the inner surface of the cylinder head in the aluminum crankshaft shell can be achieved.
In-app HVOF (
High speed oxygen fuel)
Design an automation system [Buchmann,2004], see Fig. 1.
In the automatic HVOF system, 6-
The shaft robot used to pass the HVOF torch.
Since the cylinder line needs to be rotated during the coating process, the curved box to be coated is placed on the arotary table.
The center position of the cylinder is achieved by using a linear guide system.
Motion control and motion planning are developed using control system and programming language V [R]1.
Monitor gas flow and pressure.
Depending on the type of gas and HVOFtorch [the gas controller must be selected]
Nassenstein, 2000]. [
Figure 1 slightly]
Complete Motion Analysis of the movable parts of the system involved in the coating process (
Spray light, turntable, linear guide rail)
It is essential to achieve the required coating performance.
About the properties of robot motion, coating structure and profile (e. g.
Coating Thickness)
It is greatly influenced by spraying distance, torch feed Drive and deposition angle.
In addition, the rotating speed of the table is an important parameter that affects the final geometry and performance of the thermal spray coating.
In order to obtain a uniform coating profile, the Spray Distance must remain the same.
This can be achieved by using an optimized geometric polynomial to describe the path of the torch.
This function must be specifically defined for each set of coating materials and drilling geometry to be coated.
The direction of the torch at each point of the path depends on the size of the cylinder to be coated.
The top area of the threaded hole is coated with a torch perpendicular to the surface of the cylinder.
This angle is linearly reduced to a minimum at the last point of the path.
Due to the effect of this reduced angle, this helps to reduce the deposition rate on the depth of the liner, and when the torch is guided at a constant speed, it is possible to obtain a constant coating thickness.
This problem can be solved by applying the speed profile in the torch movement, which is defined specifically for each material and a set of spray parameters, as shown in Fig. 2. [
Figure 2:
Different velocity distributions were analyzed and tested using [to optimize the HVOF spray process]Cr. sub. 3][C. sub. 2]
/NiCr 75/25 as fuel gas and propane.
Uniform coating thickness 300 [micro]
Obtained m in aluminum lining. 2.
2 Advanced Robot auxiliary processing flexible fiber fabric coating for ceramic coating on textile surface, with hard and refractive ceramic and metal top layer, is a hope to combine the advantages of technical textile with functional coating
International Journal of Technical textiles, 2004].
The coating enhances and expands the functional performance range of textiles, and the use of these technologies is growing rapidly as the application of technical textiles is becoming more and more diverse [
International Journal of Technical Texts, 2003].
Thermal spraying is a state-of-the-art coating technology for a wide range of industrial applications.
A pilot scheme for continuous coating technology textiles from \"coilto coils\" was implemented to apply thermal spraying as a new coating technology to the textile industry [Gadow, 2002], see Fig. 3. [
Figure 3 slightly]
Since the coating surface of the table carrying the fabric is convex, the robot must follow this shape well
Design the appropriate distance and angle to ensure that the coating properties and undamaged fibers remain the same.
Winding during continuous coating can drive
Stop or loop at the desired length. If non-
Stop winding. The winding machine is fed to the fabric at a coordinated speed in the area where the robot is evenly coated online.
Both winding speed and robot movement must be synchronized so that the bending distance and relative speed of the fabric and torch can be well defined.
This question uses \"x-
The \"shape\" movement of the robot and the adjusted windermovement.
If cycle operation is required, the winding machine will provide the fabric of the required length within the coating area.
Once therobot completes the move, it signals to the winding machine, allowing the new fabric parts to be transported to the coating area.
Placement on the superior deflection roller the encoder measures the exact length of the fabric that has been transported. The non-
The Stop mode has advantages for simple and uniform coating process and robot software control programming.
A communication interface in which the expected tension of the stretched fabric, the operating mode, the distance of each step, the waiting time between the step and the fabric feed can be independently controlled, located in the internal control unit of the winding machine. 3.
Conclusion The thermal spraying process can be used to improve the thermal, mechanical, electrical, magnetic and chemical properties of the surface of the component and to develop layers with specific functional properties.
In order to ensure the high repeatability of the production process, robot-assisted manufacturing is required.
Due to the important influence of torch trajectory and speed on the heat transfer process during coating manufacturing, robot motion must be optimized for each application and component geometry.
For two different practical case studies, a complete concept of motion analysis and manufacturing was developed for ecological production of cylindrical geometry. 4.
Reference materials Buchmann, M. ; Gadow, R. ; Killinger, A. ; Lopez, D.
: Number of German authorities \"Verfahrenund Vorrichtung Innenbeschichtung von Chu Hohlraumen durch thermischesSpritzen\"
DE 102 30 847, AT: 04. 07.
2002, Erteilt morning 05. 02. 2004 Gadow, R. ; von Niessen, K. ;
\"Thermal Spray ceramic coating on flexible fiber fabrics\", International thermal spray conference record, ITSC 2002, eds. C. C. Berndt; K. A. Khor; E. F.
ASM International Lugscheider, Ohio Materials Park, 2002, ISBN: 3-87155-783-8, pp. 220--
224 International Journal of Technical textiles, September 1, 2003, p.
11 International Journal of Technical textiles, October 1, 2004, government technical textiles are essential to the British economy
19 Nassenstein K. , Rickerby D. , Gent J. : \"GTV/CTA-
Control the general spraying system for HVOF guns developed for aerospace industry coatings \", fifth HVOF high speed oxygen-
Elding flame spraying, Germany, 2000 (1)
V is a registered trademark of Adept Technology Inc.
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