Welding of IN792 DS Superalloy by High Energy Density Techniques

2017 ◽  
Vol 884 ◽  
pp. 166-177 ◽  
Author(s):  
Giuliano Angella ◽  
Giuseppe Barbieri ◽  
Riccardo Donnini ◽  
Roberto Montanari ◽  
Alessandra Varone
Keyword(s):  
Electron Beam ◽  
Energy Density ◽  
Room Temperature ◽  
High Energy ◽  
The Other ◽  
High Energy Density ◽  
Process Conditions ◽  
Directionally Solidified ◽  
Thick Plates ◽  
Welding Technique

Laser (LBW) and Electron Beam (EBW) welding have been used to produce seams on 2 mm thick plates of directionally solidified (DS) IN792 superalloy. For each welding technique a grid of samples were prepared by varying the pass speed (v) and keeping constant the other process parameters. The experiments were carried out at room temperature and with pre-heating (PHT) at 200 °C and 300 °C to find the best process conditions. The microstructural changes in molten zone (MZ) and heat affected zone (HAZ) were investigated finding that EBW guarantee a better quality and efficiency of the process without any macro defects. About the microstructure, the amount of ordered γ’ phase in the MZ is similar (≈ 25 %) for both welding techniques and quite lower than the value (70 %) of the original alloy.

IN792 DS Superalloy: Optimization of EB Welding and Post-Welding Heat Treatments

2016 ◽  
Vol 879 ◽  
pp. 175-180 ◽  
Author(s):  
Giuseppe Barbieri ◽  
Peiman Soltani ◽  
Saulius Kaciulis ◽  
Roberto Montanari ◽  
Alessandra Varone
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Beam Current ◽  
Heat Treatments ◽  
The Other ◽  
Process Conditions ◽  
Eb Welding ◽  
Directionally Solidified ◽  
Thick Plates ◽  
Acceleration Voltage

Electron beam (EB) welding has been used to realize the seams on 2 mm thick plates of directionally solidified (DS) IN792 superalloy. A grid of the samples has been prepared by varying the pass speed v from 1 to 2.5 m/min, while the other process parameters (power P = 1 kW, acceleration voltage T = 50 kV, beam current I = 20 mA) were kept constant. Experiments were carried out both at room temperature and with pre-heating at 200 °C or 300 °C.Once found the best process conditions (pre-heating at 300 °C; v = 2.5 m/min) the effect of post-welding heat treatments at 700 and 750 °C for increasing time up to 2 hours has been investigated.

scholarly journals High-performance room-temperature sodium–sulfur battery enabled by electrocatalytic sodium polysulfides full conversion

2020 ◽  
Vol 13 (2) ◽  
pp. 562-570 ◽  
Author(s):  
Nana Wang ◽  
Yunxiao Wang ◽  
Zhongchao Bai ◽  
Zhiwei Fang ◽  
Xiao Zhang ◽  
...  
Keyword(s):  
Energy Density ◽  
High Performance ◽  
Room Temperature ◽  
Gold Nanoclusters ◽  
High Energy ◽  
High Energy Density ◽  
Sulfur Battery ◽  
Sodium Sulfur Battery ◽  
Sodium Sulfur ◽  
Full Conversion

Developing novel gold nanoclusters as an electrocatalyst can facilitate a completely reversible reaction between S and Na, achieving advanced high-energy-density room-temperature sodium–sulfur batteries.

Core–Shell Fe1–[email protected] Nanorods for Room Temperature All-Solid-State Sodium Batteries with High Energy Density

ACS Nano ◽  
2018 ◽  
Vol 12 (3) ◽  
pp. 2809-2817 ◽  
Author(s):  
Hongli Wan ◽  
Jean Pierre Mwizerwa ◽  
Xingguo Qi ◽  
Xin Liu ◽  
Xiaoxiong Xu ◽  
...  
Keyword(s):  
Solid State ◽  
Energy Density ◽  
Room Temperature ◽  
High Energy ◽  
High Energy Density ◽  
Core Shell ◽  
Sodium Batteries

X-ray spectroscopy and spectropolarimetry of high energy density plasma complemented by LLNL electron beam ion trap experiments

2003 ◽  
Vol 74 (3) ◽  
pp. 1947-1950 ◽  
Author(s):  
A. S. Shlyaptseva ◽  
D. A. Fedin ◽  
S. M. Hamasha ◽  
S. B. Hansen ◽  
C. Harris ◽  
...  
Keyword(s):  
Electron Beam ◽  
Energy Density ◽  
Ion Trap ◽  
High Energy ◽  
High Energy Density ◽  
X Ray ◽  
Electron Beam Ion Trap ◽  
Density Plasma

Porosity Analysis in Metal Additive Manufacturing by Micro-CT

2018 ◽  
Author(s):  
Subin Shrestha ◽  
Thomas Starr ◽  
Kevin Chou
Keyword(s):  
Additive Manufacturing ◽  
Energy Density ◽  
Pore Formation ◽  
Total Pore Volume ◽  
High Energy ◽  
High Energy Density ◽  
Process Conditions ◽  
Micro Ct ◽  
Ct Scanner ◽  
Porosity Level

This study aims at analyzing process-induced pores in selective laser melting (SLM), a laser powder-bed fusion additive manufacturing (AM) process. Porosity is one of the most problematic defects in SLM parts; it impairs the part performance, and yet, is sharply sensitive to the parameters of the SLM process itself. Detailed analysis of SLM pore formations using a computed tomography (CT) technique is desired in order to understand the porosity level under different process conditions. In this study, an SLM system was used to fabricate samples, using Ti-6Al-4V powder, with single tracks formed, at 60 μm layer thickness, with different laser powers and scanning speeds to vary the energy density. A micro-CT (μ-CT) scanner was used to measure the internal features of the SLM specimens without any post-build treatments and to analyze the porosity inside single tracks formed with different energy densities. There are different mechanisms of pore formation in SLM, in particular, this study first focuses on the pore formation due to the keyhole phenomenon, caused by a high energy density. μ-CT scanning at a 6 μm resolution is able to clearly reveal the pores in the SLM samples. From the CT scan and analysis results, it is observed that increasing the energy density increases the volume of pores. For example, with 195 W and 200 mm/s, the number of pores is 93 and the total pore volume is 0.014 mm3 for a scanning length of 12 mm. On the other hand, if the energy density is less than 0.24 J/mm, few or no pores were observed, because possibly the melting process changes from the keyhole mode to the conduction mode.

Nonrelativistic electron beam expansion in the solar corona/wind  and their type III radio bursts observed with LOFAR

2021 ◽  
Author(s):  
Hamish Reid ◽  
Eduard Kontar
Keyword(s):  
Electron Beam ◽  
Energy Density ◽  
Solar Corona ◽  
Electron Beams ◽  
Low Frequency ◽  
High Energy ◽  
High Energy Density ◽  
Moderate Intensity ◽  
Radio Bursts ◽  
Type Iii

<div> <div><span>Solar type III radio bursts contain a wealth of information about the dynamics of near-relativistic electron beams in the solar corona and the inner heliosphere; this information is currently unobtainable through other means.  Whilst electron beams expand along their trajectory, the motion of different regions of an electron beam (front, middle, and back) had never been systematically analysed before.  Using LOw Frequency ARray (LOFAR) observations between 30-70 MHz of type III radio bursts, and kinetic simulations of electron beams producing derived type III radio brightness temperatures, we explored the expansion as electrons propagate away from the Sun.  From relatively moderate intensity type III bursts, we found mean electron beam speeds for the front, middle and back of 0.2, 0.17 and 0.15 c, respectively.  Simulations demonstrated that the electron beam energy density, controlled by the initial beam density and energy distribution have a significant effect on the beam speeds, with high energy density beams reaching front and back velocities of 0.7 and 0.35 c, respectively.  Both observations and simulations found that higher inferred velocities correlated with shorter FWHM durations of radio emission at individual frequencies.  Our radial predictions of electron beam speed and expansion can be tested by the upcoming in situ electron beam measurements made by Solar Orbiter and Parker Solar Probe.</span></div> </div>

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