scholarly journals Probing of the internal damage morphology in multilayered high-temperature superconducting wires

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
You-He Zhou ◽  
Cong Liu ◽  
Lei Shen ◽  
Xingyi Zhang
Keyword(s):  
Magnetic Flux ◽  
Layer Structure ◽  
Extreme Environment ◽  
Uniaxial Tensile ◽  
Internal Damage ◽  
Amorphous Phases ◽  
Superconducting Wires ◽  
Mechanical Quality ◽  
Loading System

AbstractThe second generation HTS wires have been used in many superconducting components of electrical engineering after they were fabricated. New challenge what we face to is how the damages occur in such wires with multi-layer structure under both mechanical and extreme environment, which also dominates their quality. In this work, a macroscale technique combined a real-time magneto-optical imaging with a cryogenic uniaxial-tensile loading system was established to investigate the damage behavior accompanied with magnetic flux evolution. Under a low speed of tensile strain, it was found that the local magnetic flux moves gradually to form intermittent multi-stack spindle penetrations, which corresponds to the cracks initiated from substrate and extend along both tape thickness and width directions, where the amorphous phases at the tip of cracks were also observed. The obtained results reveal the mechanism of damage formation and provide a potential orientation for improving mechanical quality of these wires.

Mechanical quality of tissue engineered cartilage: Results after 6 and 12 weeksin vivo

2000 ◽  
Vol 53 (6) ◽  
pp. 673-677 ◽  
Author(s):  
Georg N. Duda ◽  
Andreas Haisch ◽  
Michaela Endres ◽  
Christian Gebert ◽  
Daniel Schroeder ◽  
...  
Keyword(s):  
Mechanical Quality ◽  
Engineered Cartilage

scholarly journals Edge screw withdrawal resistance in conventional particleboard and OSB: Influence of the particles type

2007 ◽  
pp. 109-117
Author(s):  
Jovan Miljkovic ◽  
Mladjan Popovic ◽  
Milanka Djiporovic-Momcilovic ◽  
Ivana Gavrilovic-Grmusa
Keyword(s):  
Oriented Strand Board ◽  
Layer Structure ◽  
Middle Layer ◽  
Root Diameter ◽  
Mean Values ◽  
Pilot Hole ◽  
Wood Particles ◽  
Screw Withdrawal ◽  
Insight Into

This research was based on presumption that the changes in size and shape of wood particles are expected to have certain impact on the particleboard quality in general. Since the conventional particleboard (PB) and oriented strand board (OSB) were built of the quite diverse wood particles, they present interesting specimens in the comparison tests. In this work, the influence of the wood particles type on the edge screw holding performance of conventional particleboard and OSB was investigated. Those tests were obtained with the screw diameters of 4.0 mm, 4.5 mm and 5 mm. Depth of embedment was 30 mm for all tests and with the pilot-hole diameter kept in the range of 80-90% in respect of the screw root diameter. Additional tests of the thickness density profile and tensile strength perpendicular to the surface of the board were conducted. Since the middle layer structure of the particleboard embeds the screw body, both mentioned parameters are considered important in the aspect of the quality of the edge screw holding performance. In order to have further insight into the conformation of the middle layer the image survey was obtained on the split board section presenting the surface of the middle layer. Significant differences in the SWR performance of OSB and PB was recorded at all screw diameters. For the screw withdrawal tests parameters OSB samples showed 56-73% superior mean values then conventional PB. On the other hand, the OSB showed wider dispersions of measured withdrawal forces at all screw diameters, which might present some of the problems in certain engineering and project calculations.

Formation and Properties of Porous Si Superlattices

1994 ◽  
Vol 358 ◽  
Author(s):  
M.G. Berger ◽  
R. Arens-Fischer ◽  
St. Frohnhoff ◽  
C. Dieker ◽  
K. Winz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Doping Level ◽  
Layer Structure ◽  
Optical Data ◽  
Type I ◽  
Optical Components ◽  
Porous Layers ◽  
Long Term Stability ◽  
Transmission Electron

ABSTRACTPorous silicon superlattices (PS-SL) were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), spectroscopic ellipsometry and reflectance spectroscopy. Type I superlattices were formed by periodically changing the current density during the etch process. The quality of the interface between layers of different porosity depends on the quality of the silicon substrate. Optical components such as Bragg reflectors or Fabry-Perot filters were designed using the optical data of single porous layers. A good long term stability of the layers is achieved by using thermal oxidation steps. Type II superlattices were formed on substrates with layers of alternating doping level. The more complex layer structure of these superlattices is explained by the selectivity of the etch process on the doping level.

THE INFLUENCE OF ADDITIVE TECHNOLOGY ON THE QUALITY OF THE SURFACE LAYER AND THE STRENGTH STRUCTURE OF PROSTHETIC CROWNS

Tribologia ◽  
2018 ◽  
Vol 280 (4) ◽  
pp. 13-22
Author(s):  
Łukasz BOJKO ◽  
Wojciech RYNIEWICZ ◽  
Anna M. RYNIEWICZ ◽  
Marcin KOT ◽  
Paweł PAŁKA
Keyword(s):  
Surface Layer ◽  
Layer Structure ◽  
Casting Process ◽  
Additive Technology ◽  
Cocrmo Alloy ◽  
Casting Technology ◽  
Stomatognathic System ◽  
Cad Cam ◽  
Hard Structures

Prosthetic crowns reproduce the damaged hard structures of the patient’s own teeth and take over their natural functions, thus securing the correct reconstruction of the stomatognathic system. The aim is to evaluate the crowns for premolars and molars produced by casting, milling, and Selective Laser Melting technologies, in terms of the accuracy of reproducing the degree against the prosthetic pillar, the analysis of the surface layer structure of the step, and the micromechanical parameters of the alloy. The study material included CoCrMo alloy crowns. The conducted study allowed finding that the tightness of prosthetic crowns made using traditional casting technology as well as in SLM milling and technology is comparable and meets clinical requirements. Structural crown analyses confirmed the very good quality of the surface layer obtained with milling technology and SLM technology using the CAD/CAM method. SLM and digital milling allow the formation of precise and durable structures constituting the foundation of crowns in a time much shorter than the casting process.

Effect of Laser Welding Parameters on Forming Behavior of Tailor Welded Blanks

2012 ◽  
Vol 445 ◽  
pp. 406-411 ◽  
Author(s):  
R. Safdarian Korouyeh ◽  
Hassan Moslemi Naeini ◽  
M.J. Torkamany ◽  
J. Sabaghzadee
Keyword(s):  
Laser Welding ◽  
Nd:Yag Laser ◽  
Dissimilar Materials ◽  
Uniaxial Tensile ◽  
Welding Parameters ◽  
Uniaxial Tensile Test ◽  
Tailor Welded Blanks ◽  
Weld Properties ◽  
Single Sheet

Tailor Welded Blanks (TWB) are blanks in which two or more sheets of similar or dissimilar materials, thicknesses, coatings etc. are welded together to form a single sheet before forming. Forming behavior of TWBs is affected by thickness ratio, strength ratio, weld conditions such as weld properties, weld orientation, weld location etc. In this work, Nd:YAG laser welding will be use to weld TWB with different thickness in experimental test. Nd:YAG laser welding parameters such as pulse duration, welding velocity, frequency and peak power will affect formability of TWBs. Taguchis design of experiments methodology is followed to design of experiment and obtain the percentage contribution of factors considered. Erichsen formability test and uniaxial tensile test (ASTM-E8) will be use in experiment setup to compare result of different welding parameters on formability quality of TWBs.

scholarly journals A Study of Internal Damage of Metal Matrix Composites by Neutron Diffraction

1994 ◽  
Vol 376 ◽  
Author(s):  
N. Shi ◽  
M. A. M. Bourke ◽  
J. A. Goldstone
Keyword(s):  
Neutron Diffraction ◽  
Elastic Strain ◽  
Tensile Loading ◽  
Uniaxial Tensile ◽  
Strain Response ◽  
Matrix Composites ◽  
Internal Damage ◽  
Sic Composites ◽  
Phase Stresses ◽  
Phase Strains

ABSTRACTUsing neutron diffraction, we have measured the elastic phase strains of Al/TiC and Al/SiC composites under uniaxial tensile loading. The phase strains were used to reconstruct the global elastic strain. It has been found that, above macroscopic yield, the global elastic strain response is not linear. A theoretical model shows that the nonlinearity is dictated by changes in the ratio of longitudinal phase stresses. Furthermore, the changes in this ratio resulting from matrix plasticity and reinforcement fracture are different which leads to distinct slope changes in the global elastic strain response that can be used to distinguish the onset of these two processes on the global elastic strain loading curve.

The mechanical ‘quality’ of osteophytes

Injury ◽  
1998 ◽  
Vol 29 (1) ◽  
pp. 31-33 ◽  
Author(s):  
Olusola O.A. Oni ◽  
Colin J. Morrison
Keyword(s):  
Mechanical Quality

Effect of Temperature and Cooling Rate on the Microstructures of 35MnB and 25Mn Tubes during Heat Treatment

2016 ◽  
Vol 866 ◽  
pp. 196-200
Author(s):  
Sun Ho Jung ◽  
S. Lee ◽  
J. Lee
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Process Condition ◽  
Effect Of Temperature ◽  
Process Conditions ◽  
Optimal Process ◽  
Steel Tubes ◽  
Band Structures ◽  
Mechanical Quality

Band structures with pearlite and ferrite aligned as stripes can be created during the heat treatment of carbon steel. Since band structures undermine the mechanical quality of end products, it is highly important to select a process condition that will not create band structures as a result of heat treatment. This study verified the effect of temperature and cooling rate on the creation of band structures during heat treatment of 35MnB and 25Mn steel tubes for drive shafts and also considered the optimal process conditions to remove band structures or prevent their creation. The experimental results suggest that, during heat treatment of 35MnB and 25Mn steel tubes, it is most effective to ensure a cooling rate faster than furnace cooling in order to prevent band structures.

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