High Performance NbMoTa–Al2O3 Multilayer Composite Structure Manufacturing by Laser Directed Energy Deposition

The conventional method of preparing metal–ceramic composite structures causes delamination and cracking defects due to differences in the composite structures’ properties, such as the coefficient of thermal expansion between metal and ceramic materials. Laser-directed energy deposition (LDED) technology has a unique advantage in that the composition of the materials can be changed during the forming process. This technique can overcome existing problems by forming composite structures. In this study, a multilayer composite structure was prepared using LDED technology, and different materials were deposited with their own appropriate process parameters. A layer of Al2O3 ceramic was deposited first, and then three layers of a NbMoTa multi-principal element alloy (MPEA) were deposited as a single composite structural unit. A specimen of the NbMoTa–Al2O3 multilayer composite structure, composed of multiple composite structural units, was formed on the upper surface of a φ20 mm × 60 mm cylinder. The wear resistance was improved by 55% compared to the NbMoTa. The resistivity was 1.55 × 10−5 Ω × m in the parallel forming direction and 1.29 × 10−7 Ω × m in the vertical forming direction. A new, electrically anisotropic material was successfully obtained, and this study provides experimental methods and data for the preparation of smart materials and new sensors.

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Two optimized post-heat treatments to achieve high-performance 90W–7Ni–3Fe alloys fabricated by laser-directed energy deposition

Materials Science and Engineering A ◽

10.1016/j.msea.2021.142561 ◽

2021 ◽

pp. 142561

Author(s):

Chao Wei ◽

Zhuang Zhao ◽

Han Ye ◽

Yang Yang ◽

Jingang Tang ◽

...

Keyword(s):

High Performance ◽

Energy Deposition ◽

Heat Treatments ◽

Directed Energy Deposition ◽

Directed Energy

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Numerical Modeling Design for the Hybrid Additive Manufacturing of Laser Directed Energy Deposition and Shot Peening Forming Fe–Cr–Ni–B–Si Alloy

Materials ◽

10.3390/ma13214877 ◽

2020 ◽

Vol 13 (21) ◽

pp. 4877

Author(s):

Xiaoyu Zhang ◽

Dichen Li ◽

Weijun Zhu

Keyword(s):

Temperature Field ◽

Additive Manufacturing ◽

Tensile Stress ◽

Compressive Stress ◽

Shot Peening ◽

Energy Deposition ◽

Hybrid Process ◽

Forming Process ◽

Directed Energy Deposition ◽

Directed Energy

Hybrid additive manufacturing is of great significance to make up for the deficiency of the metal forming process; it has been one of the main trends of additive manufacturing in recent years. The hybrid process of laser directed energy deposition (laser DED) and shot peening is a new technology combining the principles of surface strengthening and additive manufacturing, whose difficulty is to reduce the interaction between the two processes. In this paper, a new model with a discrete phase and fluid–solid interaction method is established, and the location of the shot peening point in the hybrid process is optimized. The distributions of the temperature field and powder trajectory were researched and experiments were carried out with the optimized parameters to verify simulation results. It was found that the temperature field and the powder trajectory partly change, and the optimized injection point is located in the stress relaxation zone of the material. The densities and surface residual stresses of samples were improved, and the density increased by 8.83%. The surface stress changed from tensile stress to compressive stress, and the introduced compressive stress by shot peening was 2.26 times the tensile stress produced by laser directed energy deposition.

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State of the Art in Directed Energy Deposition: From Additive Manufacturing to Materials Design

Coatings ◽

10.3390/coatings9070418 ◽

2019 ◽

Vol 9 (7) ◽

pp. 418 ◽

Cited By ~ 35

Author(s):

Adrita Dass ◽

Atieh Moridi

Keyword(s):

Additive Manufacturing ◽

High Performance ◽

Energy Deposition ◽

Future Research ◽

New Paradigm ◽

Process Map ◽

Powder Feed ◽

Directed Energy Deposition ◽

Aerospace Medical ◽

Directed Energy

Additive manufacturing (AM) is a new paradigm for the design and production of high-performance components for aerospace, medical, energy, and automotive applications. This review will exclusively cover directed energy deposition (DED)-AM, with a focus on the deposition of powder-feed based metal and alloy systems. This paper provides a comprehensive review on the classification of DED systems, process variables, process physics, modelling efforts, common defects, mechanical properties of DED parts, and quality control methods. To provide a practical framework to print different materials using DED, a process map using the linear heat input and powder feed rate as variables is constructed. Based on the process map, three different areas that are not optimized for DED are identified. These areas correspond to the formation of a lack of fusion, keyholing, and mixed mode porosity in the printed parts. In the final part of the paper, emerging applications of DED from repairing damaged parts to bulk combinatorial alloys design are discussed. This paper concludes with recommendations for future research in order to transform the technology from “form” to “function,” which can provide significant potential benefits to different industries.

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Elastic Properties of IN718 Fabricated via Laser Directed Energy Deposition (DED)

10.1115/qnde2021-74848 ◽

2021 ◽

Author(s):

M. M. Rahman ◽

G. Huanes-Alvan ◽

H. Sahasrabudhe ◽

S. K. Chakrapani

Keyword(s):

Elastic Properties ◽

Elastic Constants ◽

Laser Processing ◽

High Performance ◽

Energy Deposition ◽

Boundary Segregation ◽

Secondary Phases ◽

Directed Energy Deposition ◽

Wide Range ◽

Directed Energy

Abstract Additive manufacturing of nickel based super alloys such as IN718 is highly desirable since they have a wide range of applications in high performance structures. Compared to conventional methods, laser processing allows for near net shaping of complex geometries. However, laser processing can result in very complex microstructures including meta-stable phases, grain boundary segregation of precipitates, dendritic grains and cellular microstructure. Describing elastic properties of such structures can be quite challenging due to these features. This article explores the use of resonant ultrasound spectroscopy (RUS) to characterize the elastic properties of IN718 samples fabricated using Laser Directed Energy Deposition (DED). For initial estimates of the elastic constants, ultrasonic wave (longitudinal and shear) velocities measured at 5MHz and 2.25 MHz respectively. The initial assumption was that the eventual structure will be orthotropic and the 9 elastic constants were determined using a combination of RUS and propagating wave experiments. A finite element approach was adopted to model this system and to minimize the values of elastic constants. The results seem to suggest that the secondary phases such as Laves will influence the eventual anisotropy of the bulk structure.

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