Effects of Laser Power on the Microstructure Evolution and Mechanical Properties of Ti–6Al–4V Alloy Manufactured by Direct Energy Deposition

2021 ◽  
Author(s):  
Yukyeong Lee ◽  
Eun Seong Kim ◽  
Sangeun Park ◽  
Jeong Min Park ◽  
Jae Bok Seol ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Laser Power ◽  
Energy Deposition ◽  
Direct Energy Deposition ◽  
Direct Energy

scholarly journals A Study on the Influence of Laser Power on the Microstructure and Mechanical Properties of Functionally Graded Materials Produced by Direct Energy Deposition

2020 ◽  
Vol 58 (11) ◽  
pp. 782-792
Author(s):  
Giseung Shin ◽  
Ji hyun Yoon ◽  
Dae Whan Kim ◽  
Yongho Park ◽  
Jeoung Han Kim
Keyword(s):  
Mechanical Properties ◽  
Laser Power ◽  
Energy Deposition ◽  
Deposition Process ◽  
Functionally Graded ◽  
Direct Energy Deposition ◽  
Microstructure And Mechanical Properties ◽  
Type 316L ◽  
Direct Energy ◽  
Small Change

This study investigated the effects of laser power on the microstructure and mechanical properties of functionally gradient materials (FGM) produced by direct energy deposition. The FGM consisted of five different layers, which were a mixture of austenitic stainless steel (Type 316L) and ferritic steel (HSLA). During the direct energy deposition, two different laser power conditions (450W and 380W) were used. The ratio of Type 316L and HSAL at each deposition layers were 100:0, 65:35, 50:50, 25:75, and 0:100. After the direct energy deposition process, no cracks or delamination were seen between layers of the FGM. The effects of laser power on chemical composition and microstructure were not significant. However, as the laser power decreased, tensile strength and elongation changed with a small change in grain size.

Microstructure evolution along build direction for thin-wall components fabricated with wire-direct energy deposition

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Janmejay Dattatraya Kulkarni ◽  
Suresh Babu Goka ◽  
Pradeep Kumar Parchuri ◽  
Hajime Yamamoto ◽  
Kazuhiro Ito ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Microstructural Evolution ◽  
Microstructure Evolution ◽  
Energy Deposition ◽  
Direct Energy Deposition ◽  
Content Type ◽  
Layer Deposition ◽  
Different Types ◽  
Direct Energy ◽  
Solidification Phenomenon

Purpose The use of a gas metal arc welding-based weld-deposition, referred to as wire-direct energy deposition or wire-arc additive manufacturing, is one of the notable additive manufacturing methods for producing metallic components at high deposition rates. In this method, the near-net shape is manufactured through layer-by-layer weld-deposition on a substrate. However, as a result of this sequential weld-deposition, different layers are subjected to different types of thermal cycles and partial re-melting. The resulting microstructural evolution of the material may not be uniform. Hence, the purpose of this study is to assess microstructure variation along with the lamination direction (or build direction). Design/methodology/approach The study was carried out for two different boundary conditions, namely, isolated condition and cooled condition. The microstructural evolution across the layers is hypothesized based on experimental assessment; this included microhardness, scanning electron microscopy imaging and electron backscatter diffraction analysis. These conditions subsequently collaborated with the help of thermal modeling of the process. Findings During a new layer deposition, the previous layer also is subject to re-melt. While the newly added layer undergoes rapid cooling through a combination of convection, conduction and radiation losses, the penultimate layer, sees a slower cooling curve due to its smaller exposure area. This behavior of rapid-solidification and subsequent re-melting and re-solidification is a progressing phenomenon across the layers and the bulk of the layers have uniform grains due to this remelt-re-solidification phenomenon. Research limitations/implications This paper studies the microstructure variation along with the build direction for thin-walled components fabricated through weld-deposition. This study would be helpful in addressing the issue of anisotropy resulting from the distinctive thermal history of each layer in the overall theme of metal additive manufacturing. Originality/value The unique aspect of this paper is the postulation of a generic hypothesis, based on experimental findings and supported by thermal modeling of the process, for remelt-re-solidification phenomenon followed by temperature raising/lowering repetitively in every layer deposition across the layers. This is implemented for different types of base plate conditions, revealing the role of boundary conditions on the microstructure evolution.

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.

Analysis of microstructure and mechanical properties of additive repaired Ti–6Al–4V by Direct Energy Deposition

2020 ◽  
pp. 140604
Author(s):  
Sulochana Shrestha ◽  
Ragavendra P. Panakarajupally ◽  
Manigandan Kannan ◽  
Gregory Morscher ◽  
Andrew L. Gyekenyesi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Deposition ◽  
Direct Energy Deposition ◽  
Microstructure And Mechanical Properties ◽  
Direct Energy

Effect of recycled powder content on the structure and mechanical properties of Ti-6Al-4V alloy produced by direct energy deposition

2021 ◽  
pp. 162264
Author(s):  
Svetlana A. Shalnova ◽  
Yulia O. Kuzminova ◽  
Stanislav A. Evlashin ◽  
Olga G. Klimova-Korsmik ◽  
Artur M. Vildanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Deposition ◽  
Direct Energy Deposition ◽  
Direct Energy ◽  
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