Design of Injection Nozzle in Direct Metal Deposition (DMD) Manufacturing of Thin-Walled Structures Based on 3D Models

2016 ◽  
Author(s):  
Jingyuan Yan ◽  
Ilenia Battiato ◽  
Georges Fadel
Keyword(s):  
Laser Energy ◽  
3D Models ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Injection Nozzle ◽  
Thin Walled Structures ◽  
Nozzle Shape ◽  
Thin Walled ◽  
Manufacturing Techniques ◽  
Optimization Methodology

The Direct Metal Deposition (DMD) process is one of the most important metal based additive manufacturing techniques available today. In this study, a print head design optimization methodology is proposed based on the finite element modeling of powder distribution and substrate temperature distribution. The design methodology is applied to the deposition of Ti-6Al-4V powder in building thin-walled (≈ 0.7 mm) structures, which is also applicable to solid parts. The design objective is to find the optimal design of the injection nozzle shape that can maximize the powder usage and minimize laser energy needs, later defined as powder and laser energy efficiencies. A neural network is built to investigate the nozzle shape parameters based on the results from the 3D powder flow model. With the methodology proposed in this study, the optimal injection nozzle design can be found.

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.

Laser direct metal deposition process of thin-walled parts using variable spot by inside-beam powder feeding

2018 ◽  
Vol 24 (1) ◽  
pp. 18-27 ◽  
Author(s):  
Lifang Wang ◽  
Gangxian Zhu ◽  
Tuo Shi ◽  
Jizhuo Wu ◽  
Bin Lu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Metal Deposition ◽  
Direct Metal Deposition ◽  
Laser Spot ◽  
Layer By Layer ◽  
Single Track ◽  
Content Type ◽  
Practical Applications ◽  
Thin Walled ◽  
Powder Feeding

Purpose The purpose of this paper is to improve the forming efficiency and quality of unequal-width parts fabricated by laser direct metal deposition technology, some experiments were designed. Design/methodology/approach A new method by varying laser spot was adopted to fabricate unequal-width single track using one scanning rather than multi-track overlapping in the way of the inside-beam powder feeding, and the thin-walled parts were fabricated layer by layer. The theoretical model among layer thickness of z-axis, height of single track and the section curve order of single track was established. Findings The top surface unevenness of the thin-walled parts could be compensated automatically within the laser defocusing ranges from −2.5 to −5 mm and from 0.5 to 2.5 mm. The growth rate with the large width/height ratio was more than the small ratio, while the set height of the single track was uniform. The problem of non-uniform growth rate could be solved based on a stepped single-track method. The thin-walled parts with the smooth top surface was fabricated layer by layer which had a continuously variable width from 1 to 3 mm by splicing the laser defocusing range. Practical implications The shapes of the to-be-fabricated parts affect variable laser spot process in practical applications. For example, it will be difficult to apply variable laser spot process on the parts with the hole features. Originality/value This paper provided a guidance for forming unequal-width parts by laser direct metal deposition based on the inside-beam powder feeding.

Frame-Monolithic Technology of Construction of Low-Rise Buildings Made of Foam Gypsum and Steel Thin-Walled Structures

2018 ◽  
Vol 762 (8) ◽  
pp. 36-39 ◽  
Author(s):  
B.G. BULATOV ◽  
◽  
R.I. SHIGAPOV ◽  
M.A. IVLEV ◽  
I.V. NEDOSEKO ◽  
...  
Keyword(s):  
Thin Walled Structures ◽  
Thin Walled
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