Influence of a closed-loop controlled laser metal wire deposition process of S Al 5356 on the quality of manufactured parts before and after subsequent machining

AbstractThis paper describes the interdependence of additive and subtractive manufacturing processes using the production of test components made from S Al 5356. To achieve the best possible part accuracy and a preferably small wall thickness already within the additive process, a closed loop process control was developed and applied. Subsequent machining processes were nonetheless required to give the components their final shape, but the amount of material in need of removal was minimised. The effort of minimising material removal strongly depended on the initial state of the component (wall thickness, wall thickness constancy, microstructure of the material and others) which was determined by the additive process. For this reason, knowledge of the correlations between generative parameters and component properties, as well as of the interdependency between the additive process and the subsequent machining process to tune the former to the latter was essential. To ascertain this behaviour, a suitable test part was designed to perform both additive processes using laser metal wire deposition with a closed loop control of the track height and subtractive processes using external and internal longitudinal turning with varied parameters. The so manufactured test parts were then used to qualify the material deposition and turning process by criteria like shape accuracy and surface quality.

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In-Process and On-Machine Measurement of Machining Accuracy for Process and Product Quality Management: A Review

International Journal of Automation Technology ◽

10.20965/ijat.2014.p0004 ◽

2014 ◽

Vol 8 (1) ◽

pp. 4-19 ◽

Cited By ~ 20

Author(s):

Yasuhiro Takaya ◽

Keyword(s):

Quality Management ◽

Closed Loop ◽

Machining Process ◽

Machining Accuracy ◽

Closed Loop Control ◽

Machining Processes ◽

Loop Control ◽

Accuracy And Precision ◽

Optimal Values ◽

Work Done

In-process and on-machine measurements are used to evaluate a variety of machining factors and conditions as well as the work done on the machine tool. With the increasing complexity of machining processes and greater requirements for accuracy and precision, the demand for advanced methods for process optimization has also increased. To meet this demand, process quality management (QM) requires an expansion of manufacturing metrology to include comprehensive closed-loop control of the machining process. To eliminate the effects of disturbances on the machining process and adjust the control quantities to optimal values for robustness, in-process and on-machine measurements are very essential. In this paper, we review technical trends in in-process and on-machine measurements for process QM and conventional quality control (QC) of products. Spreading measurement targets and applications are comprehensively reviewed.

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On the Development of an Experimental Testing Platform for the Vortex Machining Process

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4025011 ◽

2013 ◽

Vol 135 (5) ◽

Cited By ~ 2

Author(s):

Stephen C. Howard ◽

Jacob W. Chesna ◽

Stuart T. Smith ◽

Brigid A. Mullany

Keyword(s):

Material Removal ◽

Closed Loop ◽

Experimental Testing ◽

Machining Process ◽

Gaussian Shape ◽

Workpiece Surface ◽

Loop Control ◽

Height Control ◽

Stability Issues ◽

Process Controls

The development of an experimental platform for studying Vortex Machining is presented. This process uses oscillating probes to generate localized vortices in polishing slurry in a region near to a workpiece surface. These vortices create material removal footprints having lateral dimensions typically measuring tens of micrometers. From studies of the process variables and subsequent machining footprints a number of process controls have been implemented and are discussed herein. These include a localized metrology frame to control specimen to probe position, coarse-fine translation axes for submicrometer motion control, closed-loop control of probe oscillation, and a slurry height control system. To illustrate the fidelity of these additional controls, the evolution from early machining footprints to the recent production of footprint arrays are presented. While process stability issues remain, machining footprints of near Gaussian shape having dimensions of 10–20 μm diameter and 40 nm depth after machining for 30 min can be reproduced.

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2-D Path Planning for Direct Laser Deposition Process

Volume 1: 36th Design Automation Conference, Parts A and B ◽

10.1115/detc2010-28440 ◽

2010 ◽

Cited By ~ 1

Author(s):

Swathi Routhu ◽

Divya Kanakanala ◽

Jianzhong Ruan ◽

Xiaoqing Frank Liu ◽

Frank Liou

Keyword(s):

Laser Scanning ◽

Tool Path ◽

Scanning Speed ◽

Deposition Process ◽

Metal Deposition ◽

Machining Process ◽

Machining Processes ◽

Direct Laser ◽

Deposition Processes ◽

Deposition Height

The zigzag and offset path have been the two most popular path patterns for tool movement in machining process. Different from the traditional machining processes, the quality of parts produced by the metal deposition process is much more dependent upon the choice of deposition paths. Due to the nature of the metal deposition processes, various tool path patterns not only change the efficiency but also affect the deposition height, a critical quality for metal deposition process. This paper presents the research conducted on calculating zigzag pattern to improve efficiency by minimizing the idle path. The deposition height is highly dependent on the laser scanning speed. The paper also discussed the deposition offset pattern calculation to reduce the height variation by adjusting the tool-path to achieve a constant scanning speed. The results show the improvement on both efficiency and height.

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Closed-Loop Control of Droplet Transfer in Electron-Beam Freeform Fabrication

Sensors ◽

10.3390/s20030923 ◽

2020 ◽

Vol 20 (3) ◽

pp. 923

Author(s):

Shuhe Chang ◽

Haoyu Zhang ◽

Haiying Xu ◽

Xinghua Sang ◽

Li Wang ◽

...

Keyword(s):

Electron Beam ◽

Real Time ◽

Closed Loop ◽

Deposition Process ◽

Closed Loop Control ◽

Droplet Transfer ◽

Loop Control ◽

Freeform Fabrication ◽

Transfer Distance ◽

Transfer State

In the process of electron-beam freeform fabrication deposition, the surface of the deposit layer becomes rough because of the instability of the feeding wire and the changing of the thermal diffusion condition. This will make the droplet transfer distance change in the deposition process, and the droplet transfer cannot always be stable in the liquid bridge transfer state. It is easy to form a large droplet or make wire and substrate stick together, which makes the deposition quality worsen or even interrupts the deposition process. The current electron-beam freeform fabrication deposition is mostly open-loop control, so it is urgent to realize the real-time and closed-loop control of the droplet transfer and to make it stable in the liquid bridge transfer state. In this paper, a real-time monitoring method based on machine vision is proposed for the droplet transfer of electron-beam freeform fabrication. The detection accuracy is up to ± 0.08 mm. Based on this method, the measured droplet transfer distance is fed back to the platform control system in real time. This closed-loop control system can stabilize the droplet transfer distance within ± 0.14 mm. In order to improve the detection stability of the whole system, a droplet transfer detection algorithm suitable for this scenario has been written, which improves the adaptability of the droplet transfer distance detection method by means of dilatation/erosion, local minimum value suppression, and image segmentation. This algorithm can resist multiple disturbances, such as spatter, large droplet occlusion and so on.

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Closed loop control of melt pool width in robotized laser powder–directed energy deposition process

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-019-04195-y ◽

2019 ◽

Vol 104 (5-8) ◽

pp. 2887-2898 ◽

Cited By ~ 6

Author(s):

Meysam Akbari ◽

Radovan Kovacevic

Keyword(s):

Energy Deposition ◽

Closed Loop ◽

Deposition Process ◽

Closed Loop Control ◽

Loop Control ◽

Melt Pool ◽

Directed Energy Deposition ◽

Directed Energy

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Study on Electro-Hydraulic Control System of the Parison Wall Thickness Based on the Double Closed-Loop Control Technology

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.278-280.1516 ◽

2013 ◽

Vol 278-280 ◽

pp. 1516-1520

Author(s):

Qiao Lian Du ◽

Ke Hua Zhang

Keyword(s):

Control System ◽

Wall Thickness ◽

High Performance ◽

Closed Loop ◽

Closed Loop Control ◽

Hydraulic Control ◽

Molding Machine ◽

Proportional Valve ◽

Loop Control ◽

Hydraulic Control System

Abstract. Parison wall thickness electro-hydraulic control system is the core of parison wall thickness control for large scale blow molding machine. In order to ensure the equalization of the wall thickness for the hollow products and to save material, in this paper analyzed the project of the parison wall thickness electro-hydraulic control system for blow molding machine and designed the parison wall thickness electro-hydraulic positional closed-loop control system which adopted the high performance proportional valve. Through simulation analysis and experiment, it was proved that through positional feedback control of the core of high performance proportional valve, the response frequency of the electro-hydraulic proportional valve can be improved so as to improve the dynamic quality of the system, achieved the requirement for higher control precision and dynamic response and satisfied the requirement for fast speed and control precision for plastic extrusion-blow hollow molding machine. It can be seen that it is effective to adopt the closed-loop control strategy for Parison wall thickness electro-hydraulic control system and more important, it has operation significance for improving the quality and ensure the precision of the products.

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The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000084 ◽

2012 ◽

Vol 220 (1) ◽

pp. 3-9 ◽

Cited By ~ 4

Author(s):

Sandra Sülzenbrück

Keyword(s):

Empirical Research ◽

Visual Feedback ◽

Closed Loop ◽

Motor Planning ◽

Visual Input ◽

Closed Loop Control ◽

Loop Control ◽

Feedback Type ◽

Effective Use ◽

The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

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