Adaptive Deposition Coverage Toolpath Planning for Metal Deposition Process

2007 ◽  
Author(s):  
Lan Ren ◽  
Jianzhong Ruan ◽  
Kunnayut Eiamsa-ard ◽  
Frank Liou
Keyword(s):  
Deposition Process ◽  
Correct Choice ◽  
Metal Deposition ◽  
Layered Manufacturing ◽  
Complete Coverage ◽  
Metal Part ◽  
Coverage Path Planning ◽  
Toolpath Planning ◽  
Deposition Processes ◽  
Major Consideration

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.

2-D Path Planning for Direct Laser Deposition Process

2010 ◽  
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.

2-D Deposition Pattern and Strategy Study on Rapid Manufacturing

2006 ◽  
Author(s):  
Jianzhong Ruan ◽  
Lan Ren ◽  
Todd E. Sparks ◽  
Frank Liou
Keyword(s):  
Tool Path ◽  
Deposition Process ◽  
Metal Deposition ◽  
Minimum Length ◽  
Machining Processes ◽  
Strategy Study ◽  
Cell Shapes ◽  
Scanning Path ◽  
Deposition Processes ◽  
D Cells

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.

A Multi-Axis Slicing Method for Direct Laser Deposition Process

2010 ◽  
Author(s):  
Divya Kanakanala ◽  
Swathi Routhu ◽  
Jianzhong Ruan ◽  
Xiaoqing Frank Liu ◽  
Frank Liou
Keyword(s):  
Deposition Process ◽  
Metal Deposition ◽  
Laser Deposition ◽  
Deposition Technique ◽  
Metal Part ◽  
Topological Information ◽  
Direct Laser Deposition ◽  
Layer Deposition ◽  
Direct Laser ◽  
Slicing Method

With multi-axis capability, direct laser deposition process can produce a metal part without the usage of support structures. In order to fully utilize such a capability, the paper discusses a slicing method for multi-axis metal deposition process. Using the geometry information of adjacent layers, the slicing direction and layer thickness can be changed as needed. A hierarchy structure is designed to manage the topological information which is used to determine the slicing sequence. Its usage is studied to build overhang type structure. With such a character, some overhang features such as holes, can be deposited directly to save the required machining operation and material cost, which improves the efficiency of the metal deposition process. Combined with direct 3D layer deposition technique, the multi-axis slicing method is implemented.

scholarly journals Occurrence of drug target residues within decantation tank sediments: a good clue to assess their historical excretion?

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Thomas Thiebault ◽  
Laëtitia Fougère ◽  
Anaëlle Simonneau ◽  
Emilie Destandau ◽  
Claude Le Milbeau ◽  
...  
Keyword(s):  
Drug Target ◽  
Chemical Properties ◽  
Deposition Process ◽  
Drug Consumption ◽  
Organic Layers ◽  
Sewer Systems ◽  
Physico Chemical ◽  
Deep Underground ◽  
Deposition Processes

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.

scholarly journals Finite element modeling of multi-pass welding and shaped metal deposition processes

2010 ◽  
Vol 199 (37-40) ◽  
pp. 2343-2359 ◽  
Author(s):  
Michele Chiumenti ◽  
Miguel Cervera ◽  
Alessandro Salmi ◽  
Carlos Agelet de Saracibar ◽  
Narges Dialami ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Metal Deposition ◽  
Element Modeling ◽  
Shaped Metal Deposition ◽  
Deposition Processes

Variable Powder Flow Rate Control in Laser Metal Deposition Processes

2008 ◽  
Author(s):  
Lie Tang ◽  
Jianzhong Ruan ◽  
Robert G. Landers ◽  
Frank Liou
Keyword(s):  
Transport System ◽  
Flow Rate ◽  
Rate Control ◽  
Metal Deposition ◽  
Powder Flow ◽  
Laser Metal Deposition ◽  
Motion System ◽  
Powder Flow Rate ◽  
Deposition Processes ◽  
Flow Rate Control

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.

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