On the solidification behaviors of AlCu5MnCdVA alloy in electron beam freeform fabrication: microstructural evolution, Cu segregation and cracking resistance

2022 ◽  
pp. 102606
Author(s):  
Ran Cui ◽  
Liang Wang ◽  
Longhui Yao ◽  
Binqiang Li ◽  
Yanqing Su ◽  
...  
Keyword(s):  
Electron Beam ◽  
Microstructural Evolution ◽  
Cracking Resistance ◽  
Freeform Fabrication

scholarly journals Online Measurement of Deposit Surface in Electron Beam Freeform Fabrication

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4001 ◽  
Author(s):  
Shuhe Chang ◽  
Haoyu Zhang ◽  
Haiying Xu ◽  
Xinghua Sang ◽  
Li Wang ◽  
...  
Keyword(s):  
Electron Beam ◽  
3D Reconstruction ◽  
Three Dimensional ◽  
Thermal Conditions ◽  
Online Measurement ◽  
Three Dimensional Reconstruction ◽  
Continuous Change ◽  
Position Information ◽  
Freeform Fabrication ◽  
Dimensional Reconstruction

In the process of electron beam freeform fabrication (EBF3), due to the continuous change of thermal conditions and variability in wire feeding in the deposition process, geometric deviations are generated in the deposition of each layer. In order to prevent the layer-by-layer accumulation of the deviation, it is necessary to perform online geometry measurement for each deposition layer, based on which the error compensation can be done for the previous deposition layer in the next deposition layer. However, the traditional three-dimensional reconstruction method that employs structured laser cannot meet the requirements of long-term stable operation in the manufacturing process of EBF3. Therefore, this paper proposes a method to measure the deposit surfaces based on the position information of electron beam speckle, in which an electron beam is used to bombard the surface of the deposit to generate the speckle. Based on the structured information of the electron beam in the vacuum chamber, the three-dimensional reconstruction of the surface of the deposited parts is realized without need of additional structured laser sensor. In order to improve the detection accuracy, the detection error is theoretically analyzed and compensated. The absolute error after compensation is smaller than 0.1 mm, and the precision can reach 0.1%, which satisfies the requirements of 3D reconstruction of the deposited parts. An online measurement system is built for the surface of deposited parts in the process of electron beam freeform fabrication, which realizes the online 3D reconstruction of the surface of the deposited layer. In addition, in order to improve the detection stability of the whole system, the image processing algorithm suitable for this scene is designed. The reliability and speed of the algorithm are improved by ROI extraction, threshold segmentation, and expansion corrosion. In addition, the speckle size information can also reflect the thermal conditions of the surface of the deposited parts. Hence, it can be used for online detection of defects such as infusion and voids.

The electron beam freeform fabrication of NiTi shape memory alloys. Part I: Microstructure and physical–chemical behavior

2020 ◽  
pp. 146442072097505
Author(s):  
RPM Guimarães ◽  
F Pixner ◽  
G Trimmel ◽  
J Hobisch ◽  
T Rath ◽  
...  
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Nickel Titanium ◽  
Freeform Fabrication ◽  
Austenitic Transformation ◽  
Columnar Grains ◽  
One Step ◽  
Niti Shape Memory Alloys

Nickel–titanium alloys are the most widely used shape memory alloys due to their outstanding shape memory effect and superelasticity. Additive manufacturing has recently emerged in the fabrication of shape memory alloy but despite substantial advances in powder-based techniques, less attention has been focused on wire-based additive manufacturing. This work reports on the preliminary results for the process-related microstructural and phase transformation changes of Ni-rich nickel–titanium alloy additively manufactured by wire-based electron beam freeform fabrication. To study the feasibility of the process, a simple 10-layer stack structure was successfully built and characterized, exhibiting columnar grains and achieving one-step reversible martensitic–austenitic transformation, thus showing the potential of this additive manufacturing technique for processing shape memory alloys.

Pulsed electron-beam treatment of WC–TiC–Co hard-alloy cutting tools: wear resistance and microstructural evolution

2000 ◽  
Vol 125 (1-3) ◽  
pp. 251-256 ◽  
Author(s):  
Y.F. Ivanov ◽  
V.P. Rotshtein ◽  
D.I. Proskurovsky ◽  
P.V. Orlov ◽  
K.N. Polestchenko ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Electron Beam ◽  
Hard Alloy ◽  
Microstructural Evolution ◽  
Cutting Tools ◽  
Electron Beam Treatment ◽  
Pulsed Electron Beam ◽  
Tools Wear

Electron Beam Freeform Fabrication on Stainless Steel

2007 ◽  
pp. 4938-4943
Author(s):  
Priti Wanjara ◽  
Mathieu Brochu ◽  
Mohammad Jahazi
Keyword(s):  
Stainless Steel ◽  
Electron Beam ◽  
Freeform Fabrication

scholarly journals Obtaining the bimetallic composition by the electron beam freeform fabrication

2019 ◽  
Vol 597 ◽  
pp. 012043 ◽  
Author(s):  
D A Gurianov ◽  
K N Kalashnikov ◽  
K S Osipovich ◽  
A V Chumaevskii
Keyword(s):  
Electron Beam ◽  
Freeform Fabrication

Temperature distribution simulations during electron beam freeform fabrication process based on the fully threaded tree

2019 ◽  
Vol 25 (6) ◽  
pp. 989-997
Author(s):  
Yajun Yin ◽  
Wei Duan ◽  
Kai Wu ◽  
Yangdong Li ◽  
Jianxin Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Temperature Distribution ◽  
Design Methodology ◽  
Content Type ◽  
Freeform Fabrication ◽  
Simulation Based ◽  
Simulation Results

Purpose The purpose of this study is to simulate the temperature distribution during an electron beam freeform fabrication (EBF3) process based on a fully threaded tree (FTT) technique in various scales and to analyze the temperature variation with time in different regions of the part. Design/methodology/approach This study presented a revised model for the temperature simulation in the EBF3 process. The FTT technique was then adopted as an adaptive grid strategy in the simulation. Based on the simulation results, an analysis regarding the temperature distribution of a circular deposit and substrate was performed. Findings The FTT technique was successfully adopted in the simulation of the temperature field during the EBF3 process. The temperature bands and oscillating temperature curves appeared in the deposit and substrate. Originality/value The FTT technique was introduced into the numerical simulation of an additive manufacturing process. The efficiency of the process was improved, and the FTT technique was convenient for the 3D simulations and multi-pass deposits.

Correlation Between Microstructure and Mechanical Properties in an Inconel 718 Deposit Produced Via Electron Beam Freeform Fabrication

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Wesley A. Tayon ◽  
Ravi N. Shenoy ◽  
MacKenzie R. Redding ◽  
R. Keith Bird ◽  
Robert A. Hafley
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Crystallographic Texture ◽  
Inconel 718 ◽  
Electron Backscatter Diffraction ◽  
Microstructural Characterization ◽  
Freeform Fabrication ◽  
Aerospace Applications ◽  
Evolution Of Microstructure ◽  
Texture Characterization

Electron beam freeform fabrication (EBF3), a metallic layer-additive manufacturing process, uses a high-power electron beam in conjunction with a metal feed wire to create a molten pool on a substrate, which on solidification produces a component of the desired configuration made of sequentially deposited layers. During the build-up of each solidified layer, the substrate is translated with respect to the electron beam and the feed wire. EBF3 products are similar to conventional cast products with regard to the as-deposited (AD) microstructure and typical mechanical properties. Inconel 718 (IN 718), a high-temperature superalloy with attractive mechanical and oxidation properties well suited for aerospace applications, is typically used in the wrought form. The present study examines the evolution of microstructure, crystallographic texture, and mechanical properties of a block of IN 718 fabricated via the EBF3 process. Specimens extracted out of this block, both in the AD and in a subsequently heat treated (HT) condition, were subjected to (1) microstructural characterization using scanning electron microscopy (SEM); (2) in-plane elastic modulus, tensile strength, and microhardness evaluations; and (3) crystallographic texture characterization using electron backscatter diffraction (EBSD). Salient conclusions stemming from this study are: (1) mechanical properties of the EBF3-processed IN 718 block are strongly affected by texture as evidenced by their dependence on orientation relative to the EBF3 fabrication direction, with the AD EBF3 properties generally being significantly reduced compared to wrought IN 718; (2) significant improvement in both strength and modulus of the EBF3 product to levels nearly equal to those for wrought IN 718 may be achieved through heat treatment.

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