Superconducting and Mechanical Properties of YBa2Cu3O7−x / Silver Granular Solids

1990 ◽  
Vol 195 ◽  
Author(s):  
H. K. Niculescu ◽  
P. J. Gielisse ◽  
Y. S. Hascicek ◽  
L. R. Testardi
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Grain Boundaries ◽  
Free State ◽  
X Ray ◽  
Twofold Increase ◽  
Wavelength Dispersive Spectrometry ◽  
Tenfold Increase ◽  
Silver Composites ◽  
The Relationship

ABSTRACTIn this paper an experimental study of YBa2Cu3O7−x/silver composites is presented and the relationship between microstructure, superconducting and mechanical properties is discussed. Silver contents ranging from 0 to 17 vol% fell all below the percolation treshold. X-ray and Wavelength Dispersive Spectrometry analyses indicate that Ag remains in a free state, and is located mainly at the grain boundaries. A tenfold increase in Jc. and a more than twofold increase in strength are the benefits of the improved microstructure of silver composites. The Tc remains unaffected.

scholarly journals Study on σ Phase in Fe–Al–Cr Alloys

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1092 ◽  
Author(s):  
Jintao Wang ◽  
Shouping Liu ◽  
Xiaoyu Han
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Thermodynamic Calculation ◽  
Second Phase ◽  
Σ Phase ◽  
Austenitic Transformation ◽  
The Matrix ◽  
The Relationship

In this paper, a method of using the second phase to control the grain growth in Fe–Al–Cr alloys was proposed, in order to obtain better mechanical properties. In Fe–Al–Cr alloys, austenitic transformation occurs by adding austenitizing elements, leading to the formation of the second phase and segregation at the grain boundaries, which hinders grain growth. FeCr(σ) phase was obtained in the Fe–Al–Cr alloys, which had grains of several microns and was coherent and coplanar with the matrix (Fe2AlCr). The nucleation of σ phase in Fe–Al–Cr alloy was controlled by the ratio of nickel to chromium. When the Ni/Cr (eq) ratio of alloys was more than 0.19, σ phase could nucleate in Fe–Al–Cr alloy. The relationship between austenitizing and nucleation of FeCr(σ) phase was given by thermodynamic calculation.

Feasibility Study on Composition and Mechanical Properties of Marine Clay Based Geopolymer Brick

2013 ◽  
Vol 594-595 ◽  
pp. 401-405
Author(s):  
S.M. Tamizi ◽  
Abdullah Mohd Mustafa Al Bakri ◽  
Hussin Kamarudin ◽  
C.M. Ruzaidi ◽  
J. Liyana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Feasibility Study ◽  
Inorganic Polymer ◽  
Synthesis Process ◽  
Local Production ◽  
Marine Clay ◽  
X Ray ◽  
Alkaline Activator

Geopolymer is an inorganic polymer performed in synthesis process of an aluminosilicate material which activated by alkaline activator solution. Marine clay, considered to be a waste substance which have an important aluminosilicate sources in developing geopolymer synthesis since it contains sufficient amounts of alumina and silica. In this experimental study, local marine clay composition was been identified to determine the amount of alumina and silica. The raw sample compositions were identified by using X-ray fluorescence (XRF). Incorporated with it composition, compressive strength of brick were been tested in aged of 1, 2 and 3 day and compared with local production of cement brick (CB). This research is aimed at determining the properties of Kuala Perlis marine clay in order to verify its suitability as a pozzolana materials as well as the sufficient amount of Al and Si to enhance the properties of geopolymer brick.

Effect of Trace Strontium Addition on Microstructure and Room Temperature Fracture Toughness of Nb-12Si-22Ti Alloys

2016 ◽  
Vol 849 ◽  
pp. 603-608 ◽  
Author(s):  
Mei Ling Wu ◽  
Feng Wei Guo ◽  
Ming Li ◽  
Ya Fang Han
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Fracture ◽  
The Relationship ◽  
Scanning Electron

The effect of strontium (Sr) addition (0.2 at.%) on the microstructure and mechanical properties of Nb-12Si-22Ti alloys were studied. Microstructure of the alloys was observed by scanning electron microscope, and their phase compositions were analyzed with X-ray diffraction and Electro-Probe Microanalyzer. The room temperature fracture toughness was measured. The results indicated that the phases of Nbss and Nb3Si were presented in Nb-12Si-22Ti alloys. However, with the Al and Sr addition, the alloys were composed of Nbss and β-Nb5Si3. Compared with the Nb-12Si-22Ti alloys, the value of room temperature fracture toughness increased about 46% and 73% with the addition of Al and Sr alloy, respectively. The relationship between the microstructure and the mechanical properties was discussed.

Experimental Study of Mechanical Properties of 30SiMn2MoVA Steel Gun Barrel Processed by Cold Radial Forging

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Yuzhao Yang ◽  
Lixia Fan ◽  
Cheng Xu ◽  
Xuehua Dong
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Elastic Limit ◽  
High Strength ◽  
Axial Direction ◽  
The State ◽  
Radial Forging ◽  
Gun Barrel ◽  
Schmid Factor ◽  
The Relationship

Abstract This work focused on the mechanical properties of 30SiMn2MoVA high strength steel gun barrel processed by cold radial forging. Three states of the tube made of this material (the state without forging, the as-forged state without annealing, and the as-forged state with annealing) were chosen to compare the axial and circumferential mechanical properties. As a result, anisotropy was found at as-forged state. The circumferential mechanical properties were inferior to the axial. The circumferential yield and tensile strength were about 150 MPa lower than the axial after forging, and the axial elongation was 155% higher than the circumferential. Even after annealing, the circumferential elongation cannot be restored to the same level as the state without forging. The reasons for anisotropy were investigated by the microstructure. The banded structure along the axial direction was observed in the forged barrel. Meanwhile, the crystalline grains of the forged gun barrel had the highest intensity of {111}〈110〉 texture which meant the grains had obvious preferential orientation. The relationship between crystallographic texture and yield strength was analyzed based on the Schmid factor. Additionally, the elastic limit internal pressure of anisotropic gun barrel was calculated, and it was lower than that under isotropic condition.

Experimental Study on Strength and other Performance of Solid Concrete Bricks Made from Recycled Coarse Aggregate

2013 ◽  
Vol 357-360 ◽  
pp. 1212-1218 ◽  
Author(s):  
Xi Xi He ◽  
Tao Zhang
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Flexural Strength ◽  
Physical Properties ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
The Impact ◽  
The Relationship

Recycled coarse aggregate solid concrete bricks were produced by QTY4-40 brick machine with strength grades of MU15-MU30. Compression and flexural strength of solid recycled coarse aggregate concrete brick were investigated. The impact of recycled aggregate on the solid concrete brick mechanical properties and physical properties was analyzed. The relationship between physical properties and strength, density was discussed.

Effect of Silk Reeling Velocity on the Aggregation Structure of Raw Silk

2011 ◽  
Vol 175-176 ◽  
pp. 496-499
Author(s):  
Li Na Li ◽  
Shi Qi Bai ◽  
Ya Qin Fu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Sonic Velocity ◽  
X Ray Diffraction ◽  
Orientation Degree ◽  
X Ray ◽  
Aggregation Structure ◽  
The Relationship ◽  
Scanning Electron

The aggregation structure of raw silk which influences the mechanical properties of raw silk directly is not only determined by the properties of cocoon but also affected by silk reeling velocity. In this study, the relationship between aggregation structure of raw silk and silk reeling velocity was studied by means of sonic velocity method, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The study showed that orientation degree, crystallinity and mechanical properties of raw silk were remarkably influenced by silk reeling velocity, and the mechanical properties of raw silk would be improved through the reasonable silk reeling velocity.

Selective laser melting dental CoCr alloy: microstructure, mechanical properties and corrosion resistance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jie Chen ◽  
Yongqiang Yang ◽  
Shibiao Wu ◽  
Mingkang Zhang ◽  
Shuzhen Mai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Vickers Microhardness ◽  
Sintering Process ◽  
Laser Melting ◽  
Content Type ◽  
X Ray ◽  
Cocr Alloy ◽  
Mechanical Properties And Corrosion ◽  
The Relationship

Purpose In this paper, the mechanical properties and corrosion resistance of CoCr alloy fabricated by selective laser melting (SLM) were studied, and the changes of performance after porcelain sintering process were also analysed. This study is to point out the relationship between the microstructure, mechanical properties and corrosion resistance of CoCr alloys prepared by SLM after porcelain sintering process. In addition, the biosafety of the sintered CoCr alloy was evaluated. Design/methodology/approach The microscopic feature changes of CoCr alloy samples after porcelain sintering process were observed by DMI 5000 M inverted metallographic microscope and Nova Nano430 FE-SEM. Moreover, phase identification and determination were conducted by X-ray diffraction (XRD) using Smartlab X-ray diffractometer. The Vickers microhardness was measured on the HVS-30 microhardness tester, and tensile tests were carried out on a CM3505 electronic universal testing machine. The corrosion resistance was tested by a classical three-point electrode system electrochemical method, then the ion precipitation was measured by using an atomic absorption spectrometer of Z2000 7JQ8024. Findings The XRD results indicate that the transition of γ phase (FCC) to e phase (HCP) occurs during the porcelain sintering processing of CoCr alloy. Moreover, the Vickers microhardness of the upper surface and the side surface of the CoCr alloy sample was improved by more than 36%. In addition, the ultimate strength of CoCr alloy via porcelain sintering treatment was increase to 1,395.3 ± 53.0 MPa compared to 1,282.7 ± 10.1 MPa of unprocessed CoCr alloy. However, the corrosion resistance of CoCr alloy samples decreases after porcelain sintering process. Originality/value There are few studies on the relationship of microstructure, mechanical properties and corrosion resistance of CoCr alloys prepared by SLM after porcelain sintering process. In this study, the microstructure, mechanical properties and corrosion resistance of CoCr alloy after porcelain sintering process were studied, and the biosafety of the alloy was evaluated. The research found that it is feasible to apply CoCr alloy fabricated by SLM to dental medicine after porcelain sintering process.

Formation of Coatings on Titanium Substrates Obtained from Mixtures of Tungsten and Cobalt Salts Using Shaped-Charge Explosion

2014 ◽  
Vol 1040 ◽  
pp. 43-46 ◽  
Author(s):  
Yu.V. Li ◽  
Sergey Kulkov ◽  
Alexander A. Kozulin ◽  
Sergey A. Kinelovskii ◽  
Sergey N. Kulkov
Keyword(s):  
Mechanical Properties ◽  
Titanium Substrate ◽  
Fluorescence Analysis ◽  
Shaped Charge ◽  
Properties Of Coatings ◽  
X Ray ◽  
Complex Salts ◽  
Substrate Surfaces ◽  
The Relationship ◽  
Titanium Substrates

In this paper the coatings on the titanium substrate surfaces obtained by the shaped-charge synthesis have been investigated. The shaped-charge synthesis was carried out using mixtures with specially synthesized complex salts containing W and Co. The studies included X-ray analysis, X-ray fluorescence analysis, and the measurements of coating microhardness. The relationship between mechanical properties of coatings and their phase and structural state has been determined.

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