A Novel Method of Estimating the Laves Phase in Electron Beam Welded Alloy 718

2008 ◽  
Vol 45 (6) ◽  
pp. 271-282
Author(s):  
K. Sivaprasad ◽  
S. Ganesh Sundara Raman ◽  
A. Sambasiva Rao
Keyword(s):  
Electron Beam ◽  
Laves Phase ◽  
Alloy 718 ◽  
Novel Method

scholarly journals Can Appropriate Thermal Post-Treatment Make Defect Content in as-Built Electron Beam Additively Manufactured Alloy 718 Irrelevant?

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 536 ◽  
Author(s):  
Sneha Goel ◽  
Kévin Bourreau ◽  
Jonas Olsson ◽  
Uta Klement ◽  
Shrikant Joshi
Keyword(s):  
Electron Beam ◽  
Process Optimization ◽  
Electron Beam Melting ◽  
Phase Distribution ◽  
Hot Isostatic Pressing ◽  
Alloy 718 ◽  
Proof Of Concept ◽  
Defect Content ◽  
Enhancing Production ◽  
Hardness Values

Electron beam melting (EBM) is gaining rapid popularity for production of complex customized parts. For strategic applications involving materials like superalloys (e.g., Alloy 718), post-treatments including hot isostatic pressing (HIPing) to eliminate defects, and solutionizing and aging to achieve the desired phase constitution are often practiced. The present study specifically explores the ability of the combination of the above post-treatments to render the as-built defect content in EBM Alloy 718 irrelevant. Results show that HIPing can reduce defect content from as high as 17% in as-built samples (intentionally generated employing increased processing speeds in this illustrative proof-of-concept study) to <0.3%, with the small amount of remnant defects being mainly associated with oxide inclusions. The subsequent solution and aging treatments are also found to yield virtually identical phase distribution and hardness values in samples with vastly varying as-built defect contents. This can have considerable implications in contributing to minimizing elaborate process optimization efforts as well as slightly enhancing production speeds to promote industrialization of EBM for applications that demand the above post-treatments.

scholarly journals Influence of build layout and orientation on microstructural characteristics of electron beam melted Alloy 718

2018 ◽  
Vol 99 (9-12) ◽  
pp. 2903-2913 ◽  
Author(s):  
P. Karimi ◽  
E. Sadeghi ◽  
D. Deng ◽  
H. Gruber ◽  
J. Andersson ◽  
...  
Keyword(s):  
Electron Beam ◽  
Alloy 718 ◽  
Microstructural Characteristics

Influence of Electron-Beam Annealing Duration on MgB2 Film Superconductivity

2013 ◽  
Vol 745-746 ◽  
pp. 255-260
Author(s):  
Xiang Dong Kong ◽  
Qian Dai ◽  
Han Li ◽  
Qing Rong Feng ◽  
Ming Zhang Chu ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Beam ◽  
High Efficiency ◽  
Beam Current ◽  
Annealing Duration ◽  
Zero Field ◽  
Superconducting Properties ◽  
Dense Structure ◽  
Novel Method ◽  
The Relationship

A novel method to fabricate Magnesium diboride ( MgB2) film by electron beam annealing was presented. The MgB2 thin films could be prepared in a second or sub-second without any toxic diborane gas, extra Mg vapor or argon gas. The method has the advantages of short formation time and high efficiency. Based on this, the relationship between MgB2 conductivity and electron beam annealing duration was investigated experimentally with an accelerating voltage of 40 × 103 V, a beam current of 3×103 A and different annealing durations of 0.1796s, 1860s, 0.2108s, 0.2200s and 0.2332s. The experimental results showed the MgB2 film with 0.2200s has the highest Tconset , the most dense structure and the strongest diamagnetic signal. Its zero-field Jc at 5 K was 5.0 × 106 A/cm2. Also the variation of the film superconducting properties with the annealing duration was found, it will provide an important reference for the preparation of high-quality MgB2 thin films.

scholarly journals Encapsulation of Electron Beam Melting Produced Alloy 718 to Reduce Surface Connected Defects by Hot Isostatic Pressing

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1226 ◽  
Author(s):  
Yunus Emre Zafer ◽  
Sneha Goel ◽  
Ashish Ganvir ◽  
Anton Jansson ◽  
Shrikant Joshi
Keyword(s):  
Electron Beam ◽  
Electron Beam Melting ◽  
Surface Defects ◽  
High Surface ◽  
Hot Isostatic Pressing ◽  
Coated Sample ◽  
Alloy 718 ◽  
Isostatic Pressing ◽  
Before And After ◽  
X Ray Computed

Defects in electron beam melting (EBM) manufactured Alloy 718 are inevitable to some extent, and are of concern as they can degrade mechanical properties of the material. Therefore, EBM-manufactured Alloy 718 is typically subjected to post-treatment to improve the properties of the as-built material. Although hot isostatic pressing (HIPing) is usually employed to close the defects, it is widely known that HIPing cannot close open-to-surface defects. Therefore, in this work, a hypothesis is formulated that if the surface of the EBM-manufactured specimen is suitably coated to encapsulate the EBM-manufactured specimen, then HIPing can be effective in healing such surface-connected defects. The EBM-manufactured Alloy 718 specimens were coated by high-velocity air fuel (HVAF) spraying using Alloy 718 powder prior to HIPing to evaluate the above approach. X-ray computed tomography (XCT) analysis of the defects in the same coated sample before and after HIPing showed that some of the defects connected to the EBM specimen surface were effectively encapsulated by the coating, as they were closed after HIPing. However, some of these surface-connected defects were retained. The reason for such remnant defects is attributed to the presence of interconnected pathways between the ambient and the original as-built surface of the EBM specimen, as the specimens were not coated on all sides. These pathways were also exaggerated by the high surface roughness of the EBM material and could have provided an additional path for argon infiltration, apart from the uncoated sides, thereby hindering complete densification of the specimen during HIPing.

scholarly journals Variation of hardness, microstructure, and Laves phase distribution in direct laser deposited alloy 718 cuboids

2017 ◽  
Vol 119 ◽  
pp. 188-198 ◽  
Author(s):  
Erica L. Stevens ◽  
Jakub Toman ◽  
Albert C. To ◽  
Markus Chmielus
Keyword(s):  
Phase Distribution ◽  
Laves Phase ◽  
Alloy 718 ◽  
Direct Laser

Mutation breeding for productive yeast strains through a novel method: High-energy-pulse-electron-beam

2008 ◽  
Vol 58 (3) ◽  
pp. 549-553 ◽  
Author(s):  
Hong Zhu ◽  
Jingzao Xu ◽  
Jun Shi ◽  
Rui Zhang ◽  
Xiaoyu Sun ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Energy ◽  
Mutation Breeding ◽  
Pulse Electron Beam ◽  
Pulse Electron ◽  
Yeast Strains ◽  
Energy Pulse ◽  
Novel Method

Spot Electron-Beam Lithography as a Novel Method of High Resolution Pattern Nanofabrication

2014 ◽  
Vol 215 ◽  
pp. 459-461
Author(s):  
Alexander S. Samardak ◽  
Margarita V. Anisimova ◽  
Alexey V. Ognev ◽  
Vadim Yu. Samardak ◽  
Liudmila A. Chebotkevich
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Electron Beam Lithography ◽  
The Novel ◽  
Practical Applications ◽  
Novel Method ◽  
20 Nm ◽  
Scanning Electron

We present a novel method of pattern nanofabrication with high resolution and small shape defects using the traditional electron-beam lithography (EBL) or only a scanning electron microscope (SEM). Our method of Spot EBL is extremely fast, highly scalable on big areas, capable of sub-20 nm resolution and fabrication of polymer patterns with complicated shapes. We show the nanostructure images fabricated by Spot EBL and propose practical applications of the novel method.

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