TEM -analysis of the BeO-dispersion in high purity Be-ingots

1978 ◽  
Vol 36 (1) ◽  
pp. 636-637
Author(s):  
Hans Migge
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Oxide Scale ◽  
High Purity ◽  
Ultrahigh Vacuum ◽  
Particle Sizes ◽  
Tem Analysis ◽  
Tremendous Importance ◽  
Thin Oxide ◽  
To Come

Inclusions of BeO are of tremendous importance on the mechanical properties of Beryllium [1,2]. The BeO particle sizes of different hot pressed materials are in the range between 400 Å and 10 μm for BeO contents between 0.5 and 3.6%[3]. However, there is no investigation about the BeO dispersion in high purity (<200 ppm BeO) ingots. Information on this subject should be derived from the diffuse Debye rings of BeO, which as yet are thought to come from the very thin oxide scale on the Be-surface [3].0.1 mm foils of Berylco IF—1 from KBI with BeO < 200 ppm were analyzed at 100 kV in the as received condition or after annealing for 1 hour at 900°C in ultrahigh vacuum. With the electron beam parallel to [00.1], [11.1], [02.1], [12.1], [03.1], [12.2] (using different grains) always four diffuse BeO rings of the type {10.0}, {10.1}, {11.0}and the unresolved {20.0}/{11.2} appear in the SAD-pattern.

Microstructural Evolution and Mechanical Properties of Electron Beam–Welded Ti70/TA5 Dissimilar Joint

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Donghui Wang ◽  
Shaogang Wang ◽  
Wen Zhang
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Electron Beam Welding ◽  
Dissimilar Joint ◽  
Welding Parameters ◽  
Tem Analysis ◽  
Β Phase ◽  
Α Phase ◽  
Joint Fracture ◽  
Phase Transmission

Abstract The dissimilar titanium alloys Ti70/TA5 are welded by using electron beam welding. The microstructure and mechanical properties of the welded joints are systematically investigated, and the welding parameters are optimized. Results show that the fusion zone (FZ) is mainly α’ martensite, and the heat-affected zone (HAZ) in the Ti70 side consists of fine α’ martensite, residual α phase, and original β phase, while the HAZ in the TA5 side is composed of coarser α phase, serrated and acicular α phase. Transmission electron microscope (TEM) analysis demonstrates that the martensite in the FZ presents the lath-like morphology. There are high-density dislocations within martensite, which has a certain orientation relationship with the β phase. Under the appropriate welding procedure, the tensile strength of the dissimilar joint is close to that of the TA5 base metal. The joint fracture dominantly presents the characteristic of ductile fracture. During welding, electron beam scanning is beneficial to improving the solidification of molten pool and grain refinement; thus, the mechanical property of the welded joint is increased to a certain extent.

scholarly journals Effect of Strain Rate on the Tensile Mechanical Properties of Electron Beam Welded OFE Copper and High-Purity Niobium for SRF Applications

2021 ◽  
Author(s):  
J.-F. Croteau ◽  
M. Peroni ◽  
S. Atieh ◽  
N. Jacques ◽  
E. Cantergiani
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Yield Stress ◽  
High Purity ◽  
High Speed ◽  
Strain Rates ◽  
High Speed Forming ◽  
Elongation To Failure ◽  
Ofe Copper ◽  
Srf Cavities

AbstractAn investigation of the tensile mechanical properties of electron beam welded OFE copper and high-purity niobium sheets is presented. Specimens were deformed in tension at strain rates ranging from 10−3 to ~ 1600 s−1. The 0.2% yield stress and ultimate tensile strength (UTS) of the welded niobium specimens are similar to those of unwelded specimens at strain rates lower or equal to 20 s−1. At higher strain rates, these mechanical properties are lower for welded niobium specimens. The 0.2% yield stress of welded OFE copper specimens is consistently lower than unwelded specimens over the range of strain rates studied, while the UTS is comparable at all strain rates. The elongation to failure of welded OFE copper specimens remains unchanged at all strain rates while the ductility of niobium specimens reduces at strain rates greater or equal to 20 s−1 and reaches a minimum at ~ 400 s−1. The effects of the weld on a non-standardized short specimen geometry, developed for this study to obtain strain rates in the order of 103 s−1, are more pronounced for niobium due to large grain sizes (up to 1200 μm) in the fusion region. However, comparable strength and ductility trends, with respect to a standard specimen, were measured at low strain rates. The conservation of strength and the relatively high ductility of the welded sheets, especially for OFE copper, suggest that bent and electron beam welded tubes could be used for the fabrication of seamless superconducting radiofrequency (SRF) cavities. These results are promising for the use of high-speed forming techniques, like electro-hydraulic forming, for the manufacturing of parts using welded tubes and sheets.

Effect of beam current on the microstructure, crystallographic texture and mechanical properties of electron beam welded high purity niobium

2021 ◽  
pp. 111318
Author(s):  
Kalyan Das ◽  
Abhishek Ghosh ◽  
Avisor Bhattacharya ◽  
Harishchandra Lanjewar ◽  
Jyotsna Dutta Majumdar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
High Purity ◽  
Crystallographic Texture ◽  
Beam Current

Effect of Space Holder Size on the Porous High Purity Aluminum Property

2020 ◽  
Vol 846 ◽  
pp. 93-98
Author(s):  
Sunisa Khamsuk ◽  
K. Choosakull ◽  
P. Wanwong
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
High Purity ◽  
Particle Sizes ◽  
Increase Particle Size ◽  
Space Holder ◽  
Porous Aluminum ◽  
High Purity Aluminum ◽  
Powder Metallurgy Route

Porous high purity aluminum was fabricated using a powder metallurgy route combined with the space holder technique. The high purity aluminum powder was mixed with three different particle sizes and contents of the space holder material. The mixed powders were cold compacted at 400 MPa and sintered at 550 °C. The effects of space holder size on the microstructure and mechanical properties of porous high purity aluminum were systematically studied. Results revealed that the size and content of the space holder materials have a significant effect on the mechanical properties of porous aluminium. The compressive strength and hardness of the porous aluminum increased as the size and amount of the space holder material increased and decreased, respectively. The thickness of the cell wall increased with an increase particle size of the space holder material.

scholarly journals Эрозия катода в газовом дуговом разряде в области пороговых токов

2021 ◽  
Vol 91 (11) ◽  
pp. 1649
Author(s):  
А.М. Мурзакаев
Keyword(s):  
High Purity ◽  
Erosion Rate ◽  
Experimental Studies ◽  
Ultrahigh Vacuum ◽  
Particle Sizes ◽  
Arc Discharges ◽  
Pulsed Arc

The results of experimental studies of the erosion rate of high-purity tungsten cathodes after pulsed arc discharges in a pure oil-free ultrahigh vacuum and in gases of various purities are reported. The erosion rate in high-purity argon does not change compared to the rate of erosion of electrodes in a pure oil-free vacuum. The rate of erosion in "technical" argon is 10% less than the rate of erosion of electrodes in an oil-free vacuum. The rate of erosion in "technical" nitrogen is 15-35% less than the rate of erosion of electrodes in vacuum. Particle sizes formed in gas arcs are smaller than those formed in vacuum arcs.

Effects of particle sizes, wood to cement ratio and chemical additives on the properties of sesendok (Endospermum Diadenum) cement-bonded particleboard

2010 ◽  
Vol 7 (2) ◽  
pp. 57
Author(s):  
Jamaludin Kasim ◽  
Shaikh Abdul Karim Yamani ◽  
Ahmad Firdaus Mat Hedzir ◽  
Ahmad Syafiq Badrul Hisham ◽  
Mohd Arif Fikri Mohamad Adnan
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Cement Content ◽  
Particle Sizes ◽  
Thickness Swelling ◽  
Chemical Additives ◽  
Board Density ◽  
Cement Ratio ◽  
Aluminium Silicate ◽  
Cement Board

An experimental investigation was performed to evaluate the properties of cement-bonded particleboard made from Sesendok wood. The target board density was set at a standard 1200 kg m". The effect offarticle size, wood to cement ratio and the addition ofsodium silicate and aluminium silicate on the wood cement board properties has been evaluated. A change ofparticle size from 1.0 mm to 2.0 mm has a significant effect on the mechanical properties, however the physical properties deteriorate. Increasing the wood to cement ratio from 1:2.25 to 1:3 decreases the modulus ofrupture (MOR) by 11% and the addition ofsodium silicate improves valuesfurther by about 28% compared to the addition ofaluminum silicate. The modulus ofelasticity (MOE) in general increases with increasing cement content, but is not significantly affected by the addition ofsodium silicate or aluminium silicate, although the addition of their mixture (sodium silicate andaluminium silicate) consistentlyyields greater MOE values. Water absorption and thickness swelling is significantly affected by the inclusion ofadditives and better values are attained using higher wood to cement ratios.

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