Effects of Processing Parameters on Powder Utilization Ratio during Laser Metal Deposition Shaping

2012 ◽  
Vol 549 ◽  
pp. 790-794 ◽  
Author(s):  
Kai Zhang ◽  
Xin Min Zhang ◽  
Wei Jun Liu
Keyword(s):  
Laser Power ◽  
Gas Flow ◽  
Feeding Rate ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Layer By Layer ◽  
Laser Metal Deposition ◽  
Forming Efficiency ◽  
Utilization Ratio ◽  
Powder Feeding

The Laser Metal Deposition Shaping (LMDS) process involves injecting metallic powder into a molten pool created by a high power industrial laser. As the laser traverses across the substrate in a layer-by-layer fashion, a fully dense metal is left in its path. A few processing parameters involved with the LMDS include the laser power, traverse speed, powder feeding rate, and gas flow rate, etc, which affect many factors of LMDS technology. Among them, the powder utilization ratio is an important one because it directly determines the build rate and build height per layer. Due to some objective reasons, the powder utilization ratio is far less than 100%. In order to ensure the stability of LMDS technology, it is necessary to investigate the match between powder utilization ratio and build rate and forming efficiency, and grasp the influence rules of processing parameters on powder utilization ratio. Accordingly, the related experiments were performed with the varied laser power, scanning speed and powder feeding rate. The results prove that the powder utilization ratio is a varied value, and affected by the processing parameters. Consequently, the relative ideal parameter match should be chosen in accordance with the specific circumstances during the LMDS technology, thus ensuring the better powder utilization ratio and promoting the forming efficiency and economic benefit.

scholarly journals Ultrasonic-Assisted Laser Metal Deposition of the Al 4047Alloy

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1111 ◽  
Author(s):  
Zhang ◽  
Guo ◽  
Chen ◽  
Kang ◽  
Cao ◽  
...  
Keyword(s):  
Relative Density ◽  
Laser Power ◽  
Tensile Ductility ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Ultrasonic Power ◽  
Laser Metal Deposition ◽  
Ultrasonic Assisted ◽  
Cast Alloys ◽  
Cast Parts

Ultrasonic-assisted laser metal deposition(UALMD) technology was used to fabricate Al 4047 parts. The effect of the powder feeding laser power, remelting laser power and ultrasonic power on the relative density of the parts was investigated. The relative density, microstructure and mechanical properties of the specimens obtained by the optimized process parameters were compared with the corresponding properties of the cast alloys. The results showed that dense alloys with a maximum density of 99.1% were prepared using ultrasonic vibration and by remelting the previously deposited layer with the optimized processing parameters, and its density was almost equivalent to that of the cast parts. The microstructure of the samples using optimal laser parameters presented columnar Al dendrites and equiaxed Si particles at the boundary of each deposited layer, while the supersaturated Al solid solution was transformed into equiaxed crystal surrounded by fine fibrous Si phases at the center of the layer. Moreover, the size of the primary Al and the Si particles in the samples produced by UALMD was remarkably refined compared to that of the primary Al and Si particles in the cast structure, resulting in grain refining strengthening. The observed variation in the microstructure had an obvious impact on the tensile properties. The mechanical behavior of the deposit obtained by UALMD revealed superior tensile strength, yield strength and tensile ductility values of 227 ± 3 MPa, 107 ± 4 MPa and 12.2 ± 1.4%, which were approximately 51%, 38% and 56% higher than those of the cast materials, respectively.

Additive Manufacturing

2019 ◽  
pp. 165-183 ◽  
Author(s):  
Kamardeen Olajide Abdulrahman ◽  
Esther T. Akinlabi ◽  
Rasheedat M. Mahamood
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Titanium Aluminide ◽  
Three Dimensional ◽  
Physical And Mechanical Properties ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Layer By Layer ◽  
Laser Metal Deposition ◽  
Additive Process

Three-dimensional printing has evolved into an advanced laser additive manufacturing (AM) process with capacity of directly producing parts through CAD model. AM technology parts are fabricated through layer by layer build-up additive process. AM technology cuts down material wastage, reduces buy-to-fly ratio, fabricates complex parts, and repairs damaged old functional components. Titanium aluminide alloys fall under the group of intermetallic compounds known for high temperature applications and display of superior physical and mechanical properties, which made them most sort after in the aeronautic, energy, and automobile industries. Laser metal deposition is an AM process used in the repair and fabrication of solid components but sometimes associated with thermal induced stresses which sometimes led to cracks in deposited parts. This chapter looks at some AM processes with more emphasis on laser metal deposition technique, effect of LMD processing parameters, and preheating of substrate on the physical, microstructural, and mechanical properties of components produced through AM process.

Control Module of Laser Metal Deposition Shaping System

2011 ◽  
Vol 480-481 ◽  
pp. 644-649
Author(s):  
Kai Zhang ◽  
Xiao Feng Shang ◽  
Wei Jun Liu
Keyword(s):  
Motion Control ◽  
Computer Control ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Layer By Layer ◽  
Laser Metal Deposition ◽  
Control Module ◽  
Software Structure ◽  
Shaping System ◽  
Rapid Prototyping And Manufacturing

The Laser Metal Deposition Shaping (LMDS) is a state-of-the-art technology which correlates the Rapid Prototyping and Manufacturing (RP&M) and laser processing. During this process, a certain alloy is fused onto the surface of a substrate. Laser deposition devices, namely powder feeder, CNC worktable, and laser shutter, are integrated to automatically make any cladding profile possible. Material is deposited by scanning the laser across a surface while injecting metallic powders into the molten pool at the laser focus. The metal part is then fabricated layer by layer. The LMDS system consists of four primary components: energy supply module, motion control module, powder delivery module, and computer control module. These modules of LMDS system individually perform the specified functions, but coordinate with each other. One of them, the control module plays an important role in causing the LMDS system automatic and intelligent. The control module can be divided into hardware and software components. The hardware structure mainly includes industrial computer, motors, and motion control card, which build the overall framework, and are driven by software structure. The software structure, namely the system application program with GUI, can instruct every module of LMDS system to finish the motion cooperatively adjust the processing parameters freely, and fulfill the LMDS technology automatically and intelligently. The hardware and software structures work in harmony with each other, thus flexibly controlling the LMDS system.

Cladding of Stellite-6/WC Composites Coatings by Laser Metal Deposition

2018 ◽  
Vol 941 ◽  
pp. 1645-1650 ◽  
Author(s):  
Takahiro Kunimine ◽  
Ryusei Miyazaki ◽  
Yorihiro Yamashita ◽  
Yoshinori Funada ◽  
Yuji Sato ◽  
...  
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Metal Deposition ◽  
Matrix Composites ◽  
Laser Metal Deposition ◽  
Feeding Rates ◽  
Coating Materials ◽  
Cross Sectional ◽  
Stellite 6 ◽  
Powder Feeding

This study aims to investigate the microstructure and hardness of multi-layered Stellite-6/WC metal-matrix composites coatings on metallic substrates cladded by laser metal deposition (LMD) for improvement of wear and corrosion resistances. As coating materials, Stellite-6 and WC-12wt.%Co powders were selected. Powder mixtures having various mixing-ratios of Stellite-6 and WC-12wt.%Co were provided vertically on S45C substrates by controlling powder feeding rates of the two powder feeders, individually. Stellite-6/WC composites which consist of three layers with different compositions were cladded on the S45C substrates by laser melting. Cross-sectional microstructure observation was carried out by using an optical microscope (OM). Vickers microhardness tests were conducted to evaluate hardness of the cladding layers and substrates. The experimental results demonstrate that hard multi-layered Stellite-6/WC metal-matrix composites coatings were successfully cladded on the S45C substrates. Property gradients in the Stellite-6/WC composites could be made due to the position-dependent chemical composition and microstructure made by controlling powder feeding rates of an LMD system.

Direct energy deposition metamodeling using a meshless method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Boussad Abbes ◽  
Tahar Anedaf ◽  
Fazilay Abbes ◽  
Yuming Li
Keyword(s):  
Surrogate Model ◽  
Manufacturing Process ◽  
Laser Power ◽  
Energy Deposition ◽  
Feeding Rate ◽  
Maximum Temperature ◽  
Direct Energy Deposition ◽  
Content Type ◽  
Direct Energy ◽  
Powder Feeding

Purpose Direct energy deposition (DED) is an additive manufacturing process that allows to produce metal parts with complex shapes. DED process depends on several parameters, including laser power, deposition rate and powder feeding rate. It is important to control the manufacturing process to study the influence of the operating parameters on the final characteristics of these parts and to optimize them. Computational modeling helps engineers to address these challenges. This paper aims to establish a framework for the development, verification and application of meshless methods and surrogate models to the DED process. Design/methodology/approach Finite pointset method (FPM) is used to solve conservation equations involved in the DED process. A surrogate model is then established for the DED process using design of experiments with powder feeding rate, laser power and scanning speed as input parameters. The surrogate model is constructed using neutral networks (NN) approximations for the prediction of maximum temperature, clad angle and dilution. Findings The simulations of thin wall built of Ti-6Al-4V titanium alloy clearly demonstrated that FPM simulation is successful in predicting temperature distribution for different process conditions and compare favorably with experimental results from the literature. A methodology has been developed for obtaining a surrogate model for DED process. Originality/value This methodology shows how to achieve realistic simulations of DED process and how to construct a surrogate model for further use in optimization loop.

Height Dependent Laser Metal Deposition Process Modeling

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Patrick M. Sammons ◽  
Douglas A. Bristow ◽  
Robert G. Landers
Keyword(s):  
Heat Transfer ◽  
Critical Role ◽  
Metal Deposition ◽  
Lumped Parameter Model ◽  
Analytical Models ◽  
Layer By Layer ◽  
Laser Metal Deposition ◽  
Melt Pool ◽  
Solid Region ◽  
Scan Speed

Laser metal deposition (LMD) is used to construct functional parts in a layer-by-layer fashion. The heat transfer from the melt region to the solid region plays a critical role in the resulting material properties and part geometry. The heat transfer dynamics can change significantly as the number of layers increase, depending on the geometry of the sub layers. However, this effect is not taken into account in previous analytical models, which are only valid for a single layer. This paper develops a layer dependent model of the LMD process for the purpose of designing advanced layer-to-layer controllers. A lumped-parameter model of the melt pool is introduced and then extended to include elements that capture height dependent effects on the melt pool dimensions and temperature. The model dynamically relates the process inputs (laser power, material mass flow rate, and scan speed) to the melt pool dimensions and temperature. A finite element analysis (FEA) is then conducted to determine the effect of scan speed and part height on the solid region temperature gradient at the melt pool solidification boundary. Finally, experimental results demonstrate that the model successfully predicts multilayer phenomenon for two deposits on two different substrates.

Evaluation of the Stability and Precision of Powder Delivery during Laser Additive Manufacturing

2013 ◽  
Vol 380-384 ◽  
pp. 4348-4352
Author(s):  
Kai Zhang ◽  
Lei Wang ◽  
Xiao Feng Shang
Keyword(s):  
Laser Beam ◽  
Molten Pool ◽  
Gas Flow ◽  
Feeding Rate ◽  
Shielding Gas ◽  
Metal Parts ◽  
Deposited Metal ◽  
Computer Aided ◽  
The Stability ◽  
Powder Feeding

The fabrication of metal parts is the backbone of the modern manufacturing industry. Laser forming is combination of five common technologies: lasers, rapid prototyping (RP), computer-aided design (CAD), computer-aided manufacturing (CAM), and powder metallurgy. The resulting process creates part by focusing an industrial laser beam on the surface of processing work piece to create a molten pool of metal. A small stream of powdered alloy is then injected into the molten pool to build up the part gradually. By moving the laser beam back and forth and tracing out a pattern determined by a CAD, the solid metal part is fabricated line by line, one layer at a time. By this method, a material having a very fine microstructure due to rapid solidification process can be produced. In the present work, a type of direct laser deposition process, called Laser Metal Deposition Shaping (LMDS), has been employed and developed to fabricate metal parts. In the LMDS process, the powder delivery system is an important component to perform the powder transport from powder storage box to powder nozzle, which supplies the raw material for the as-deposited metal parts. Consequently, the stability and precision of powder delivery during LMDS is essential to achieve the metal parts with high quality, so it is critical to evaluate the main factors closely related to the stability and precision of powder delivery. The shielding gas flow and the powder feeding rate were ascertained through experimental measure and formula calculation. The results prove that the suitable shielding gas flow and powder feeding rate can promote the stability and precision of powder delivery, which is the basis for the fabrication of as-deposited metal parts with flying colors.

Effect of Powder Flow Rate and Gas Flow Rate on the Evolving Properties of Deposited Ti6Al4V/Cu Composites

2014 ◽  
Vol 1016 ◽  
pp. 177-182 ◽  
Author(s):  
Mutiu F. Erinosho ◽  
Esther Titilayo Akinlabi ◽  
Sisa Pityana
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Pure Copper ◽  
Metal Deposition ◽  
Powder Flow ◽  
Laser Metal Deposition ◽  
Gas Flow Rate ◽  
Flow Rates ◽  
Powder Flow Rate ◽  
Hardness Values

—Pure copper was deposited with Ti6Al4V alloy via laser metal deposition (LMD) process to produce Ti6Al4V/Cu composites. This paper reports the effect of powder flow rate (PFR) and gas flow rate (GFR) of laser metal deposited Ti6Al4V/Cu composites. The deposited samples were characterised through the evolving microstructure and microhardness. It was observed that the PFR and GFR have an influence on the percentage of porosity present in the samples. The higher the flow rates of the powder and the gas, the higher the degree of porosity and vice versa. The widmanstettan structures were observed to be finer as the flow rate reduces which in turn causes a decrease in the hardness values of the deposited composites. The hardness values varied between HV381.3 ± 60 and HV447.3 ± 49.

Repetitive Process Control of Laser Metal Deposition

2014 ◽  
Author(s):  
Patrick M. Sammons ◽  
Douglas A. Bristow ◽  
Robert G. Landers
Keyword(s):  
Process Control ◽  
Dynamic Models ◽  
Open Loop ◽  
Metal Deposition ◽  
Hammerstein Model ◽  
Layer By Layer ◽  
Laser Metal Deposition ◽  
Material Source ◽  
Stabilizing Controller ◽  
Repetitive Process

The Laser Metal Deposition (LMD) process is an additive manufacturing process in which a laser and a powdered material source are used to build functional metal parts in a layer by layer fashion. While the process is usually modeled by purely temporal dynamic models, the process is more aptly described as a repetitive process with two sets of dynamic processes: one that evolves in position within the layer and one that evolves in part layer. Therefore, to properly control the LMD process, it is advantageous to use a model of the LMD process that captures the dominant two dimensional phenomena and to address the two-dimensionality in process control. Using an identified spatial-domain Hammerstein model of the LMD process, the open loop process stability is examined. Then, a stabilizing controller is designed using error feedback in the layer domain.

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