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.

scholarly journals Influence of Rapid Solidification and Optimized Process Parameters on the Microstructural Evolution of Additive Manufactured Titanium Alloy Grade 5 Composite

2021 ◽  
Vol 309 ◽  
pp. 01147
Author(s):  
O.S. Fatoba ◽  
S.A. Akinlabi ◽  
O.M. Ikumapayi ◽  
E.T. Akinlabi
Keyword(s):  
Process Parameters ◽  
Laser Scanning ◽  
Gas Flow ◽  
Laser System ◽  
Scanning Speed ◽  
Deposition Process ◽  
Cooling Rates ◽  
Grade 5 ◽  
Direct Laser ◽  
Columnar Grains

The study experimentally investigates the effects that Ytterbium Laser System process parameters, such as laser power, powder feed rate and traverse speed, has on the resultant microstructure of Ti- 6Al-4V grade 5 alloy. The deposition process was conducted employing a 3kW (CW) Ytterbium Laser System (YLS-2000-TR) machine, coaxial to the reinforcement powder. The laser scanning speed and power were varied between the intervals of 1-1.2 m/min and 900-1000 W. All other parameters kept constant where the rate of gas flow, the spot diameter, and the rate of powder flow. The microstructure was characterized by grain size and morphology by using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). The microstructural and mechanical properties were ascertained and the relationships with the process parameters were achieved. As a result of rapid cooling, the morphological features of α and α’ are distinctive and appear acicular. The structures appear coarsened. The metallurgy of the samples identifies with a morphology of multi-scale; with the coarsened alpha structures being reduced, plate-like, discrete and finer. The alpha grains closer to the fusion zone grew epitaxially, and the ones above these are acicular and lamellar. The results also indicated that slow traverse speeds increase the scale of columnar grains, while other process parameters were kept constant. Columnar microstructures became prevalent due to the dynamic temperature gradients/spikes, and sustainable cooling rates, pertaining to fabricating direct laser deposited Ti-6Al-4V grade 5 alloy. It was ascertained that by increasing the traverse speeds, the cooling rates increased, which resulted in a decrease in the width of the columnar grains.

Optimizing the Efficiency in Direct Laser Deposition Process Using Vibrations of Nozzle to Control the Flow of Powder

2014 ◽  
Author(s):  
Kamran Nazir ◽  
Chang Hyun Sohn ◽  
Fahad Hassan ◽  
Muhammad Awais ◽  
Muhammad Ali ◽  
...  
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Laser Scanning ◽  
Experimental Studies ◽  
Scanning Speed ◽  
Deposition Process ◽  
Deposition Efficiency ◽  
Laser Deposition ◽  
Direct Laser Deposition ◽  
Direct Laser

In direct laser deposition (DLD), metallic powder is injected into the melt pool in order to join different metals to develop fully dense and near net shape part. The cost of powder wasted in commercial DLD machines has been a major concern to the industries. More than 60% of the powder is wasted and is being disposed off which make the system economically and environmentally expensive. Recycling of powder is not feasible in many sectors, because of the fear of drop in the quality of the product. The objective of this study is to enhance the deposition efficiency of the DLD process, so that to minimize the amount of powder wasted. In present study, flow of powder is achieved by vibration of the powder delivery nozzle at sonic frequencies. Experimental studies are performed to analyze the deposition of powder by varying laser intensities, powder flow rate and laser scanning speed. The mass flow during certain time is weighed and the actual clad weight that is formed during the same period is weighted. The difference of the two is used to calculate the powder efficiency. Different set of experiments are performed. Powder mass flow rates are increased subsequently and Taguchi matrix are prepared for each set of experiment. Mass flow rate in initial experiments is from 0.044 grams/sec to 0.244 g/s and increases up to 0.86 g/s in the final set of experiments. Laser power during these experiments varies between 1KW to 2 KW, while laser scanning speeds varies from 100 mm/min to 350 mm/min. Maximum deposition efficiency is achieved in initial set of experiments and is up to 70%, which is significant improvement in the form of deposition efficiencies available in literature.

scholarly journals 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

2021 ◽  
Author(s):  
Dina Becker ◽  
Steffen Boley ◽  
Rocco Eisseler ◽  
Thomas Stehle ◽  
Hans-Christian Möhring ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Closed Loop ◽  
Deposition Process ◽  
Metal Wire ◽  
Machining Process ◽  
Machining Processes ◽  
Initial State ◽  
Additive Process ◽  
Shape Accuracy ◽  
Loop Control

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.

A novel approach to machining process fault detection using unsupervised learning

2020 ◽  
pp. 095440542093755
Author(s):  
Thomas McLeay ◽  
Michael S Turner ◽  
Keith Worden
Keyword(s):  
Fault Detection ◽  
Unsupervised Learning ◽  
Tool Path ◽  
Cutting Tool ◽  
Novelty Detection ◽  
Cutting Parameters ◽  
Machining Process ◽  
Machining Processes ◽  
Workpiece Material ◽  
Data Set

The most common machining processes of turning, drilling, milling and grinding concern the removal of material from a workpiece using a cutting tool. The performance of machining processes depends on a number of key method parameters, including cutting tool, workpiece material, machine configuration, fixturing, cutting parameters and tool path trajectory. The large number of possible configurations can make it difficult to implement fault detection systems without having to train the system to a particular method or fault type. The research of this article applies a novel method to detect the changing state of a process over time in order to detect faulty machining conditions such as worn tools and cutting depth changes. Unlike studies in the previous literature in this domain, an unsupervised learning method is used, so that the method can be applied in production to unfamiliar processes or fault conditions. In the case presented, novelty detection is applied to a multivariate sensor feature data set obtained from a milling process. Sensor modalities include acoustic emission, vibration and spindle power and time and frequency domain features are employed. The Mahalanobis squared-distance is used to measure discordancy of each new data point, and values that exceed a principled novelty threshold are categorised as fault conditions.

Experimental Study of Micromachining on Borosilicate Glass Using CO2 Laser

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Vishnu Vardhan Posa ◽  
Murali Sundaram
Keyword(s):  
Laser Scanning ◽  
Laser Energy ◽  
Removal Rate ◽  
Scanning Speed ◽  
Machining Process ◽  
Laser Machining ◽  
Glass Work ◽  
Workpiece Material ◽  
Laser Parameters ◽  
Wide Range

Abstract Laser beam machining (LBM) is a versatile process that can shape a wide range of engineering materials such as metals, ceramics, polymers, and composite materials. However, machining of glass materials by LBM is a challenge as most of the laser energy is not absorbed by the surface. In this study, an attempt has been made to increase the absorptivity of the glass material by using a coating on the surface of the material. Glass has been used in this study because of its extensive applications in the micro-opto-electro-mechanical systems. The optimal machining depends on both laser parameters and properties of the workpiece material. There are number of laser parameters that can be varied in the laser machining process. It is difficult to find optimal laser parameters due to the mutual interaction of laser parameters. A statistical study based on design of experiment (DoE) has been made to study the effect of coating and parameters like laser power, laser scanning speed, angle of inclination of the workpiece on depth of the slot, width of the slot, aspect ratio, and material removal rate (MRR) in the laser machining process using 2k factorial design and analysis of variance (ANOVA). On an average, four times increase in depth of the slot, two times increase in width of the slot and seven times increase in the MRR were observed in the glass samples with coating when compared to uncoated glass work samples.

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.

Microstructural Enhancement and Performance of Additive Manufactured Titanium Alloy Grade 5 Composite Coatings

2020 ◽  
Author(s):  
O. S. Fatoba ◽  
S. A. Akinlabi ◽  
E. T. Akinlabi ◽  
L. C. Naidoo ◽  
A. A. Adediran ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Laser Scanning ◽  
Gas Flow ◽  
Composite Coatings ◽  
Laser System ◽  
Scanning Speed ◽  
Deposition Process ◽  
Traverse Speed ◽  
Industrial Applications ◽  
Grade 5

Abstract The surface integrity of Titanium alloy may be improved by surface modification, to expand its availability for more diverse industrial applications. Additive manufacturing is a commercially competitive manufacturing technique with the possibility of altering the entire perception of design and fabrication. The study experimentally investigates the effects that Ytterbium Laser System process parameters, such as laser power, powder feed rate and traverse speed, has on the resultant microstructure of Ti-6Al-4V grade 5 alloy. The deposition process was conducted employing a 3kW (CW) Ytterbium Laser System (YLS-2000-TR) machine, coaxial to the reinforcement powder. The laser scanning speed and power were varied between the intervals of 1–1.2 m/min and 900–1000 W. All other parameters kept constant were the rate of gas flow, the spot diameter, and the rate of powder flow. The microstructure was characterized by grain size and morphology by using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). During the DLMD process, the thermal histories induced in the process led to the promotion of the transformed α+β microstructure from the initial primary a microstructure; the growth and evolution of the distinct grain morphologies and stability of the alpha and beta structures upon increased and reduced structures. It was ascertained that by increasing the traverse speeds, the cooling rates increased, which resulted in the decrease in the width of the columnar grains.

2D longitudinal modeling of heat transfer and fluid flow during multilayered direct laser metal deposition process

2012 ◽  
Vol 24 (3) ◽  
pp. 032008 ◽  
Author(s):  
Simon Morville ◽  
Muriel Carin ◽  
Patrice Peyre ◽  
Myriam Gharbi ◽  
Denis Carron ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Deposition Process ◽  
Metal Deposition ◽  
Longitudinal Modeling ◽  
Laser Metal Deposition ◽  
Direct Laser ◽  
Direct Laser Metal Deposition

Characterization of Colmonoy 227-F Samples Obtained by Direct Laser Metal Deposition

2009 ◽  
Vol 83-86 ◽  
pp. 842-849 ◽  
Author(s):  
Andrea Angelastro ◽  
Sabina L. Campanelli ◽  
Antonio D. Ludovico
Keyword(s):  
Computer Aided Design ◽  
Complex Geometry ◽  
Scanning Speed ◽  
Glass Container ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Metal Powders ◽  
Wide Range ◽  
Direct Laser ◽  
Direct Laser Metal Deposition

Direct Laser Metal Deposition (DLMD) is an emerging technique in the group of Material Accretion Manufacturing (MAM) processes because of the possibility to fabricate and to repair a wide range of metal components with a complex geometry, starting from metal powders. DLMD is a technology which combines computer aided design, laser cladding and rapid prototyping. Fully dense metallic parts can be directly obtained through melting coaxially fed powders with a laser. The success of this technology in the die and tool industry depends on the parts quality to be achieved. An accurate control of the parameters such as laser power, spot diameter, scanning speed and powder mass flow rate is fundamental to obtain the required geometric dimensions and material properties. In this work, the performance of the DLMD process was examined in terms of hardness, porosity, microstructure, and composition. A fitting equipment was built and used for the experiments together with a CO2 laser machine with a maximum power of 3 kW. The material used for experimental tests was Colmonoy 227-F, a Nickel alloy specially designed for glass container mould protection and restoration.

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