Research on Technics of Laser Direct Metal Deposition Forming Technology

2009 ◽  
Vol 69-70 ◽  
pp. 54-58
Author(s):  
Wei Zhang ◽  
Jian Hua Yao
Keyword(s):  
Laser Power ◽  
Scanning Speed ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Solidification Velocity ◽  
Technological Parameters ◽  
Technical Parameters ◽  
Forming Technology ◽  
Average Hardness ◽  
Feeding Speed

The technological parameters of laser direct metal deposition (DMD) were researched by DMD forming experiments using 2Cr13 powder. Fixing other parameters, the lower of laser power, the smaller the characteristic sizes of cladding layer are. Increasing of laser power, cladding height would firstly increase and then decrease, cladding width would firstly increase and then almost maintain constant, while cladding depth would gradually increase. When other parameters are invariable, with increasing of powder feeding speed, cladding height would increase, cladding width and cladding depth would decrease. When other parameters are invariable, cladding width, cladding height and cladding depth would decrease with the adding of scanning speed. The microstructure of single track cladding had three typical patterns, cellular dendritic, column dendritic and equiaxed crystal. The patterns depended on the temperature gradient and the solidification velocity. Under different technical parameters, the average hardness of specimens would change from 300HV0.2 to 550HV0.2.

A Mathematical Model-Based Optimization Method for Direct Metal Deposition of Multimaterials

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Jingyuan Yan ◽  
Ilenia Battiato ◽  
Georges M. Fadel
Keyword(s):  
Inconel 718 ◽  
Laser Power ◽  
Laser Energy ◽  
Scanning Speed ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Fabrication Process ◽  
Optimal Solutions ◽  
Multi Objective Optimization ◽  
Multi Objective

During the past few years, metal-based additive manufacturing technologies have evolved and may enable the direct fabrication of heterogeneous objects with full spatial material variations. A heterogeneous object has potentially many advantages, and in many cases can realize the appearance and/or functionality that homogeneous objects cannot achieve. In this work, we employ a preprocess computing combined with a multi-objective optimization algorithm based on the modeling of the direct metal deposition (DMD) of dissimilar materials to optimize the fabrication process. The optimization methodology is applied to the deposition of Inconel 718 and Ti–6Al–4V powders with prescribed powder feed rates. Eight design variables are accounted in the example, including the injection angles, injection velocities, and injection nozzle diameters for the two materials, as well as the laser power and scanning speed. The multi-objective optimization considers that the laser energy consumption and the powder waste during the fabrication process should be minimized. The optimization software modeFRONTIER® is used to drive the computation procedure with a matlab code. The results show the design and objective spaces of the Pareto optimal solutions and enable the users to select preferred setting configurations from the set of optimal solutions. A feasible design is selected which corresponds to a relatively low material cost, with laser power 370 W, scanning speed 55 mm/s, injection angles 15 deg, injection velocities 45 m/s for Inconel 718, 30 m/s for Ti–6Al–4V, and nozzle widths 0.5 mm under the given condition.

Technical Parameters Model of Laser Direct Metal Deposition

2011 ◽  
Vol 217-218 ◽  
pp. 1633-1636
Author(s):  
Wei Zhang ◽  
Jian Hua Yao
Keyword(s):  
Energy Balance ◽  
Balance Equation ◽  
Laser Power ◽  
Energy Balance Equation ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Beam Radius ◽  
Theoretical Principle ◽  
Scanning Velocity ◽  
Technical Parameters

This paper was focus on the technical parameters matching model of laser direct metal deposition（DMD）forming. Based on a series of DMD forming experiments, the energy balance equation of laser power, beam radius, powder feeding velocity and scanning velocity was established which could provide a theoretical principle for parameter selection and optimizing.

Experimental Study on Pore-Defect by Selective Laser Melting of 316L Stainless Steel

2019 ◽  
Vol 801 ◽  
pp. 239-244
Author(s):  
Xin Yu Liu ◽  
Lu Pan ◽  
Wen Hao Wang ◽  
Si Yao Li
Keyword(s):  
Stainless Steel ◽  
Energy Density ◽  
Laser Power ◽  
316L Stainless Steel ◽  
Scanning Speed ◽  
Micro Structure ◽  
Technological Parameters ◽  
Product Density ◽  
Air Bubble ◽  
Test Verification

With different process parameters (laser power, scanning speed and scanning distance),the low-time defects of forming part were studied by microscope,including air bubble, pore, micro-crack and macro-crack. The formation mechanism of pore-defect was analyzed. The micro-structure and composition of the pore-defect were studied by means of SEM and EDS. The results showed that the porosity mainly included circular air porosity, irregular process porosity and oxide inclusion.Linear energy density (E=P/v) was introduced as synthetic parameter.According to analysis and test verification, the optimum technological parameters of 316L stainless steel were laser power 190-210KW, laser speed 800-1000mm/s and scanning interval 0.9-0.11mm,and the linear energy density was about 200J/m. There were no cracks, no bubbles, a small amount of porosity, and the product density reached 99.7%.

Process Planning for Multi-Directional Laser-Based Direct Metal Deposition

2005 ◽  
Vol 219 (7) ◽  
pp. 695-707 ◽  
Author(s):  
R Dwivedi ◽  
R Kovacevic
Keyword(s):  
Process Planning ◽  
Laser Power ◽  
Large Family ◽  
Coordinated Control ◽  
Traverse Speed ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Powder Feed Rate ◽  
Mathematical Basis ◽  
Control Of Parameters

Laser-based direct metal deposition has demonstrated the capability to deposit metal along multiple directions. Suitable control of parameters, namely, the metal-powder feed rate, the traverse speed, and the laser power allow fabrication of a desired shape for a large family of parts. The capability to deposit material along multiple directions eliminates the requirement for support structures. However, accessing the point of deposition and manipulating the direction of deposition require a coordinated control of two kinematical systems; one is related to the deposition platform, whereas the other is related to the deposition head. The identification of the key challenges, a mathematical basis of the process, possible solutions, the subsequent process planning, and experimental results are the subjects of this article.

Development of Bio-Compatible Metallic Structures Using Direct Metal Deposition Process

2012 ◽  
Vol 576 ◽  
pp. 141-145
Author(s):  
Syed H. Riza ◽  
Syed H. Masood ◽  
Cui'e Wen ◽  
William Song
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Laser Power ◽  
Deposition Process ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Metal Powders ◽  
Micro Hardness ◽  
Metallic Structures ◽  
Ti6al4v Titanium Alloy

This paper investigates the capabilities of Direct Metal Deposition (DMD) process, which is a novel additive manufacturing technique, for creating structures that can be used as bone implants. Emphasis is on the use of bio-compatible metals, because metals are the most suitable materials in terms of mechanical strength when the requirement arises for supporting and replacing the load bearing bones and joints such as hip and knee. Specimens using two different metal powders, 41C stainless steel and Ti6Al4V titanium alloy, are generated by DMD process on mild steel and titanium plates as substrates respectively. Metallographic samples were made from the cladding, and tested for surface roughness and micro-hardness. The results indicate that at low laser power, hard and strong structures with good porosity can be successfully created using the DMD system.

Experimental Study Based on the Widening Melting Roads Cladding Forming of the Hollow Laser

2013 ◽  
Vol 419 ◽  
pp. 180-185
Author(s):  
Liang Liang Yu ◽  
Shi Hong Shi ◽  
Ge Yan Fu ◽  
Mei Ling Tian
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Research Group ◽  
Laser Power ◽  
New Technology ◽  
Scanning Speed ◽  
Feeding Speed ◽  
Series Of Experiments ◽  
Cladding Layers ◽  
Powder Feeding

Our research group has invented a kind of new technology called coaxial inside-beam powder feeding. By series of experiments, this paper analyzed and summarized the process parameters’ influence on the cladding layers’ feature and quanlity, which contain the laser power P, the powder feeding speed Vf, the scanning speed Vs and the defocusing distance L. Some cladding experiments also were made to aquire the cladding roads with variable width. The experimental results indicate that when P, Vf and D×Vs are fixed, roads with stable height and uniformly changing width are acquired by changing Vs and L at the same time.

An Experimental Characterization of Powder/Substrate Interaction during Direct Metal Deposition for Additive Manufacturing

2019 ◽  
Vol 813 ◽  
pp. 435-440
Author(s):  
Maurizio Troiano ◽  
Alessia Teresa Silvestri ◽  
Fabio Scherillo ◽  
Andrea El Hassanin ◽  
Roberto Solimene ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Surface Morphology ◽  
Laser Power ◽  
Surface Characterization ◽  
Spot Size ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Metal Powders ◽  
Substrate Interaction

The physical behavior of metal powders during laser-based additive manufacturing processes has been investigated. In particular, an experimental campaign of direct metal deposition has been carried out to evaluate the effect of the laser power and spot size on the powder/substrate interaction and on the surface morphology of the final piece. A fast-camera has been used to evaluate the interaction phenomena during the printing process, while confocal microscopy has been carried out to measure the surface morphology of the samples. Results highlighted that increasing the laser power and laser spot size, the particle impact velocity is about constant, while the powder/laser/substrate interaction zone increases. As a consequence, the mean thickness increases, as confirmed by surface characterization.

scholarly journals Research on the Effect of Key Technological Parameters on Molten Pool during Selective Laser Melting Processing

2021 ◽  
Vol 2097 (1) ◽  
pp. 012016
Author(s):  
Wentong Wang ◽  
Linfeng Tang ◽  
Congyan Chen ◽  
Yu Li ◽  
Tao Zhou
Keyword(s):  
Temperature Field ◽  
Selective Laser Melting ◽  
Molten Pool ◽  
Laser Power ◽  
Reference Value ◽  
Scanning Speed ◽  
Ansys Software ◽  
Technological Parameters ◽  
Laser Melting ◽  
Forming Process

Abstract Selective laser melting (SLM), as an emerging technology in additive manufacturing, often has various defects in the forming process. To ensure the consistency and stability of the parts forming quality, the effects of two typical technological parameters, laser power and scanning speed, on the temperature of molten pool are investigated in this paper. Firstly, the temperature field of Ti-6Al-4V is simulated theoretically via ANSYS software, and the effects of two typical technological parameters on the temperature field are studied. Then, in the experiment, using the designed radiation monitoring device and Ti-6Al-4V powder as forming material, the influence of these two typical factors on the state of molten pool is studied. The simulation and experimental results show that the temperature of molten pool shows positive correlation with the laser power and negative correlation with the scanning speed. This will provide a certain reference value for upgrading and optimizing SLM equipment.

Effect of Linear Energy Density on Bubble-Defect of 316L Stainless Steel by Selective Laser Melting

2019 ◽  
Vol 803 ◽  
pp. 32-36
Author(s):  
Wen Hao Wang ◽  
Xin Yu Liu ◽  
Lu Pan
Keyword(s):  
Stainless Steel ◽  
Energy Density ◽  
Laser Power ◽  
316L Stainless Steel ◽  
Scanning Speed ◽  
Technological Parameters ◽  
Laser Melting ◽  
Product Density ◽  
Air Bubble ◽  
Test Verification

In the experiments of different process parameters (laser power, scanning speed and scanning distance),the low-time defects of forming part were studied by microscope,including air bubble, pore, micro-crack and macro-crack. The formation mechanism of bubble-defect was analyzed.Linear energy density (E=P/v) was introduced as synthetic parameter.According to analysis and test verification, the optimum technological parameters of 316L stainless steel were laser power 190-210KW, laser speed 800-1000mm/s and scanning interval 0.9-0.11mm,and the linear energy density was about 200J/m. There were no cracks, no bubbles, a small amount of porosity, and the product density reached 99.7%.

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