2-D Deposition Pattern and Strategy Study on Rapid Manufacturing

Author(s):  
Jianzhong Ruan ◽  
Lan Ren ◽  
Todd E. Sparks ◽  
Frank Liou

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 will result in different shapes in the metal deposition process with about the same input geometry. This paper presents the research conducted on the effect of various scanning patterns and strategies for the deposition results. Triangle and rectangle patterns are selected as basic 2-D “cells” to plan the scanning path. Several criteria, like minimum angle, minimum length of edge, etc. are defined to categorize the different “cell” shapes. Based on deposition results, the suitable patterns are determined for each type. The previously defined patterns are applied for each cell in order to achieve the optimal quality. The experiment has demonstrated that the pattern and strategy selection has improved the deposition quality significantly.

Author(s):  
Swathi Routhu ◽  
Divya Kanakanala ◽  
Jianzhong Ruan ◽  
Xiaoqing Frank Liu ◽  
Frank Liou

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.


Author(s):  
Lan Ren ◽  
Jianzhong Ruan ◽  
Kunnayut Eiamsa-ard ◽  
Frank Liou

Coverage toolpath planning is very critical to deposition quality in layered manufacturing especially for metal deposition processes. The correct choice of toolpath patterns will make it possible to build a fully dense and functional metal part. The major consideration when selecting a toolpath pattern is the complete coverage of the to-be-deposited geometry which means no voids should happen. This paper presents the research on the toolpath coverage efficiency and the strategies to predict the possibility of the occurrence of deposition voids so that the appropriate toolpath pattern can be applied to avoid deposition voids. The contour-parallel offsetting pattern and the adaptive zigzag toolpath pattern will be applied as the alternate options and the final adaptive deposition coverage toolpath will be the combination of these two basic patterns depending on the prediction results of the occurrence of the deposition voids. The experiment has demonstrated that the adaptive toolpath pattern can greatly improve the reliability of the coverage path planning in deposition processes.


Author(s):  
Jianzhong Ruan ◽  
Kunnayut Eiamsa-ard ◽  
Jun Zhang ◽  
F. W. Liou

With the integration of multi-axis layered manufacturing and material removal (machining) processes, a hybrid system has more capability and flexibility to build complicated geometry with a single setup. Process planning to integrate the two different processes is a key issue. In this paper, an algorithm of adaptive slicing for five-axis Laser Aided Manufacturing Process (LAMP) is summarized which can generate uniform- or non-uniform slices. In order to avoid interruption in the deposition process for one slice, a skeleton-based offset deposition tool-path method is used to generate continuous moving paths. A method to build a non uniform (thickness) layer which utilizes two processes is presented and an overall algorithm for integration is described. The newly developed algorithm implemented in the process planning helps the hybrid system build part more efficiently.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Thomas Thiebault ◽  
Laëtitia Fougère ◽  
Anaëlle Simonneau ◽  
Emilie Destandau ◽  
Claude Le Milbeau ◽  
...  

AbstractThis study investigated the potential of sediments accumulated in sewer systems to record human activities through the occurrence of drug target residues (DTR). The installation studied is 17 m deep underground decantation tank that traps the coarse fractions of a unitary sewer system (northern part of Orléans, France), collecting both stormwater and wastewater. The sediments deposited in this tank could constitute a nonesuch opportunity to study the historical evolution of illicit and licit drug consumption in the catchment, however, the deposition processes and the record of DTRs remain largely unknown at present. Five cores were acquired from 2015 to 2017. One hundred fifty-two sediment samples were extracted using a mixture of ultra-pure water:methanol (1:1) prior to analysis of the extracts by high-pressure liquid chromatography coupled to tandem mass spectrometry. Several classical sedimentological analyses such as total organic carbon, facies description and granulometry were also performed on these samples, in order to understand the most important factors (e.g., physico-chemical properties of the DTRs, solid type, assumed load in wastewater) impacting their deposition.The key role of the speciation of DTRs was highlighted by the higher contents in neutral and anionic DTRs in organic layers, whereas only cationic DTRs were found in mineral layers. The considerable modifications in the sediments’ properties, generated by distinct origins (i.e., stormwater or wastewater), are therefore the most important drivers that must be taken into account when back-calculating the historical patterns of drug consumption from their DTR concentrations in decantation tank sediments. Further research remains necessary to fully understand the deposition process, but this study provides new clues explaining these temporal evolutions.


Author(s):  
Dina Becker ◽  
Steffen Boley ◽  
Rocco Eisseler ◽  
Thomas Stehle ◽  
Hans-Christian Möhring ◽  
...  

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.


2010 ◽  
Vol 199 (37-40) ◽  
pp. 2343-2359 ◽  
Author(s):  
Michele Chiumenti ◽  
Miguel Cervera ◽  
Alessandro Salmi ◽  
Carlos Agelet de Saracibar ◽  
Narges Dialami ◽  
...  

Author(s):  
Lie Tang ◽  
Jianzhong Ruan ◽  
Robert G. Landers ◽  
Frank Liou

This paper proposes a novel method, called Variable Powder Flow Rate Control (VPFRC), for the regulation of powder flow rate in laser metal deposition processes. The idea of VPFRC is to adjust the powder flow rate to maintain a uniform powder deposition per unit length even when disturbances occur (e.g., the motion system accelerates and decelerates). Dynamic models of the powder delivery system motor and the powder transport system (i.e., five–meter pipe, powder dispenser, and cladding head) are constructed. A general tracking controller is then designed to track variable powder flow rate references. Since the powder flow rate at the nozzle exit cannot be directly measured, it is estimated using the powder transport system model. The input to this model is the DC motor rotation speed, which is estimated on–line using a Kalman filter. Experiments are conducted to examine the performance of the proposed control methodology. The experimental results demonstrate that the VPFRC method is successful in maintaining a uniform track morphology, even when the motion system accelerates and decelerates.


ChemCatChem ◽  
2015 ◽  
Vol 7 (22) ◽  
pp. 3674-3682 ◽  
Author(s):  
Sam Kalirai ◽  
Ulrike Boesenberg ◽  
Gerald Falkenberg ◽  
Florian Meirer ◽  
Bert M. Weckhuysen

2021 ◽  
Vol 13 (15) ◽  
pp. 8303
Author(s):  
Vu Tuan Anh ◽  
Pham Ba Trung ◽  
Kim-Anh Nguyen ◽  
Yuei-An Liou ◽  
Minh-Thu Phan

This paper aims to identify the causes and sources of erosion and deposition at small estuaries in southern central Vietnam under human intervention. The jetty built at the Tam Quan river mouth (Binh Dinh Province, Vietnam) serves as the base for the study. After its completion at the end of 2009, the hydrodynamic and erosion-deposition processes in the region have been significantly altered. Inside the estuary, the waves are not influenced, but the currents are increased during the ebb tide period and decreased during the flood tide timeframe. During the southwest monsoon, the jetty could cause an increase in the deposition process in both frequency and area, whereas the erosion process tends to narrow the area and increase the frequency on the north coast. In contrast, both deposition and erosion processes are increased on the southern coast. About 5859 m3 of sediments are deposited in the channel gate mainly by local sources. During the northeast monsoon, both deposition and erosion processes are located over a narrow area with frequency increased on the north coast, whereas the deposition process is narrowed with higher frequency on the southern coast. The total amount of sediment deposited at the estuary is 56,446 m3, of which 74.2% is from the onsite erosion material, 15.8% from the river and 10% from the longshore transportation. Generally, due to mainly erosion-deposition processes, sediment volume is accumulated during the northeast monsoon with amount 9.6 times more than that the southwest monsoon. The erosion-deposition processes are contributed to by poor practical management and local human activities inland and in the coastal regions, as well as the natural situation, resulting in serious impacts on society, the economy and the environment. Hence, the governance of the erosion-deposition processes and sediment load in small estuaries appear to contribute to the master plan for the local sustainable development of society and the economy.


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