scholarly journals A study on mechanical properties of ferritic alloy by physical testing for nuclear power fusion reactors

2021 ◽  
Vol 2083 (2) ◽  
pp. 022088
Author(s):  
Wenqing Jia ◽  
Xiangbing Liu ◽  
Minyu Fan ◽  
Chaoliang Xu ◽  
Yuanfei Li ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Mechanical Test ◽  
Strengthening Effect ◽  
Test Results ◽  
Ferritic Alloy ◽  
Ferritic Alloys ◽  
Failure Mode Transition ◽  
Cr Content ◽  
Physical Testing ◽  
Ferrite Steel

Abstract The ferrite plays an important role in key component materials for nuclear power plant. The study was performed on ferritic alloys with various Cr content ranging from 10 to 38wt%. The Vickers-hardness and mechanical test results indicate that the high Cr content will cause a hardening and strengthening effect on the ferrite steel. Meanwhile, it can be concluded that the ferritic alloy suffers a reduction of toughness and a failure mode transition from ductile to brittle fracture with the increasing Cr content from the SEM fractography analysis.

scholarly journals Performance Study of Grass-Derived Nano-Cellulose and Polycaprolactone Composites for 3D Printing

2021 ◽  
Vol 11 (3) ◽  
pp. 1273
Author(s):  
Chen Feng ◽  
Jiping Zhou ◽  
Xiaodong Xu ◽  
Yani Jiang ◽  
Hongcan Shi ◽  
...  
Keyword(s):  
3D Printing ◽  
Mechanical Test ◽  
Chemical Properties ◽  
Test Results ◽  
Performance Study ◽  
Compression Process ◽  
Ansys Fluent ◽  
Nano Cellulose ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, 3D printing has received increasing attention from researchers. This technology overcomes the limitations of traditional technologies by printing precise and personalized scaffold with arbitrary shapes, pore structures, and porosities for the applications in various tissues. The cellulose nanocrystal (CNC) is extracted from Humulus Japonicus (HJS) and mixed with poly(ε-caprolactone) (PCL) to prepare a series of CNC/PCL composites for printing. Based on the analysis of the physical and chemical properties of the series of the CNC/PCL composites, an optimal mass ratio of CNC to PCL was obtained. The Solidworks was used to simulate the stretching and compression process of the scaffolds with three different patterns under an external force. The flow of nutrient solution in the scaffolds with different patterns was simulated by ANSYS FLUENT, and then a new optimization scaffold pattern with a concave hexagon shape was advised based on the simulation results. Collectively, the mechanical test results of the material and scaffold confirmed that the optimal filling amount of the CNC was 5%, and the scaffold pattern with concave hexagon shape exhibited better mechanical properties and suitable for the transport of cells and nutrients, which is expected to be more widely used in 3D printing.

Transient liquid phase bonding of Cu and Al using metallic particles interlayers

2021 ◽  
pp. 095440542098823
Author(s):  
Alireza Zaheri ◽  
Mohammadreza Farahani ◽  
Alireza Sadeghi ◽  
Naser Souri
Keyword(s):  
Liquid Phase ◽  
Mechanical Test ◽  
Transient Liquid Phase ◽  
Transient Liquid Phase Bonding ◽  
Joint Interface ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metallic Particles ◽  
Powder Interlayer

The bonding strength, and microstructures of Cu and Al couples using metallic powders as interlayer during transient liquid phase bonding (TLP bonding) were investigated. The interfacial morphologies and microstructures were studied by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and X-ray diffraction. First, to explore the optimum bonding time and temperature, nine samples were bonded without interlayers in a vacuum condition. Mechanical test results indicated that bonding at 560°C in 20 min returns the highest bond strength (84% of Al). This bonding condition was used to join ten samples with powder interlayers. Powders were prepared by mixing different combinations of Cu, Al (+Fe nanoparticles) and Zn. In the bonding zone, different Cu9Al4, CuAl, and CuAl2 intermetallic co-precipitate. The strongest bonding is formed in the sample with the 70Al (+Fe)-30Cu powder interlayer. Powder interlayers present thinner and more uniform intermetallic layers at the joint interface.

Research of Technology for Repair of Heat Exchangers of Nuclear Power Plants by Laser Welding

2021 ◽  
Vol 313 ◽  
pp. 94-105
Author(s):  
A. Bernatskyi ◽  
V. Sydorets ◽  
O.M. Berdnikova ◽  
I. Krivtsun ◽  
O. Kushnarova
Keyword(s):  
Service Life ◽  
Laser Welding ◽  
Welded Joints ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Mechanical Test ◽  
Austenitic Steels ◽  
Depth Of Penetration

Extending the lifetime of energy facilities is extremely important today. This is especially true of nuclear power plants, the closure (or modernization) of which poses enormous financial and environmental problems. High-quality repair of reactors can significantly extend their service life. One of the critical parts is heat exchangers, the tubes of which quite often fail. Sealing, as a type of repair of heat exchanger tubes by the plugs, is promising provided that the joint quality is high. Practical experience in the use of welding to solve this problem has shown the need to search technological solutions associated with increasing the depth of penetration and reducing the area of thermal effect. The aim of the work was to develop a highly efficient technology for repair and extension of service life of heat exchangers of nuclear power plants based on the results of studying the technological features of laser welding of joints of dissimilar austenitic steels AISI 321 and AISI 316Ti in the vertical spatial position. Based on the results of the analysis of mechanical test data, visual and radiographic control, impermeability tests and metallographic studies of welded joints, the appropriate modes of laser welding of plugs have been determined. The principal causes of defects during laser welding of annular welded joints of dissimilar stainless steels are determined and techniques for their elimination and prevention of their formation are proposed. Based on the results of the research, technological recommendations for laser welding of plugs in the heat exchange tube of the collector are formulated, which significantly improves the technology of repair of steam generators of nuclear power plants and extends the service life of reactors.

Effects of cross-linking by MgCl2 as an initiator on the properties of EVOH

2020 ◽  
pp. 089270572091331
Author(s):  
Bin Wang ◽  
Chong Lu ◽  
Jing Hu ◽  
Weixin Lu
Keyword(s):  
Mechanical Test ◽  
Barrier Properties ◽  
Thermomechanical Properties ◽  
Cross Linking ◽  
Resonance Spectroscopy ◽  
Test Results ◽  
Ethylene Vinyl Alcohol ◽  
Ftir Spectrometry ◽  
Stretching Vibration ◽  
C Nmr

Ethylene vinyl alcohol (EVOH) with excellent barrier properties has insufficient thermomechanical properties. The introduction of magnesium chloride (MgCl2) as an initiator in EVOH blends improved its properties by cross-linking. Torque behavior and gel experiment analysis indicated that a cross-linking in EVOH was formed. The cross-linking mechanism was confirmed through 13C nuclear magnetic resonance spectroscopy (13C NMR) and Fourier-transform infrared (FTIR) spectrometry. In 13C NMR spectra, the splitting peaks of CH carbon and CH2 carbon tended to disappear, and the stretching vibration peak of –C=C– was observed in the FTIR spectra. The formation of hydrogen bond between MgCl2 and EVOH destroyed the intramolecular and intermolecular hydrogen bonds of EVOH, which contributed to the dehydration of –OH to form –C=C–, and –C=C– was the basis for a cross-linking reaction. The thermal analysis of blends demonstrated that the melting temperature and crystallization temperature decreased, and the crystallinity gradually disappeared when the MgCl2 content increased. Glass transition temperature significantly increased as the intermolecular force enhanced. Thermogravimetric analysis showed that a cross-linked structure could improve the thermostability of EVOH with an increase in the MgCl2 content. Mechanical test results revealed a remarkable increase in the tensile strength of EVOH as the MgCl2 content increased.

scholarly journals Flexural Strengthening of Concrete Slab-Type Elements with Textile Reinforced Concrete

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2246 ◽  
Author(s):  
Hyeong-Yeol Kim ◽  
Young-Jun You ◽  
Gum-Sung Ryu ◽  
Kyung-Taek Koh ◽  
Gi-Hong Ahn ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Tensile Test ◽  
Tensile Properties ◽  
Surface Coating ◽  
Strengthening Effect ◽  
Test Results ◽  
Short Fibers ◽  
Textile Reinforced Concrete ◽  
Flexural Strengthening ◽  
The Matrix

This paper deals with flexural strengthening of reinforced concrete (RC) slabs with a carbon textile reinforced concrete (TRC) system. The surface coating treatment was applied to a carbon grid-type textile to increase the bond strength. Short fibers were incorporated into the matrix to mitigate the formation of shrinkage-induced cracks. The tensile properties of the TRC system were evaluated by a direct tensile test with a dumbbell-type grip method. The tensile test results indicated that the effect of the surface coating treatment of the textile on the bonding behavior of the textile within the TRC system was significant. Furthermore, the incorporation of short fibers in the matrix was effective to mitigate shrinkage-induced crack formation and to improve the tensile properties of the TRC system. Six full-scale slab specimens were strengthened with the TRC system and, subsequently, failure tested. The ultimate load-carrying capacity of the strengthened slabs was compared with that of an unstrengthened slab as well as the theoretical solutions. The failure test results indicated that the stiffness and the ultimate flexural capacity of the strengthened slab were at least 112% and 165% greater, respectively, than that of the unstrengthened slab. The test results further indicated that the strengthening effect was not linearly proportional to the amount of textile reinforcement.

scholarly journals Natural Mordenite from Spain as Pozzolana

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1220
Author(s):  
Leticia Presa ◽  
Jorge L. Costafreda ◽  
Domingo A. Martín ◽  
Isabel Díaz
Keyword(s):  
Mechanical Test ◽  
Low Cost ◽  
Principal Component ◽  
Test Results ◽  
Mechanical Compression ◽  
San Jose ◽  
X Ray Diffraction ◽  
Pozzolanic Cement ◽  
Natural Clinoptilolite ◽  
Potential Use

This work deals with anomalous concentrations of natural mordenite in the southeast of Spain. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies evidenced that the samples contain mainly monomineral zeolitic phase of mordenite (70% to 74%), usually accompanied by smectite (montmorillonite), the principal component of bentonite. A study of the applicability of these zeolites is presented to establish the potential use as pozzolanic cements. For comparative purposes, synthetic commercial mordenite is also characterized and tested. The initial mixtures were prepared using cement and mordenite at a 75:25 ratio. Chemical analysis and a pozzolanicity test showed the high pozzolanic character. These mixtures were further added to sand and water, yielding the cement specimens to be used as concrete. Mechanical test results showed that the mechanical compression at 7 and 28 days fall into the range of 19.23 to 43.05 MegaPascals (MPa) for the cement specimens built with natural mordenites. The obtained results fall in the same range of cement specimens prepared with natural clinoptilolite, using mixtures within the European requirement for commercial concretes. Thus, these results and the low cost of natural mordenite of San José de los Escullos deposit supports the potential use of natural mordenite as pozzolanic cement.

scholarly journals Optimized Analysis Method for Evaluating the Shear Strength Parameters of Rock Joint Surfaces

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yao Xiao ◽  
Huafeng Deng ◽  
Jingcheng Fang ◽  
Hengbin Zhang ◽  
Jianlin Li
Keyword(s):  
Shear Strength ◽  
Empirical Equation ◽  
Mechanical Test ◽  
Rock Joint ◽  
Test Results ◽  
Analysis Method ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Joint Surfaces ◽  
Multiple Sample

The results obtained from the mechanical test of rock samples inevitably suffer dispersion owing to discrepancies between test specimens. In view of these deficiencies, the present study proposes a method based on the empirical equation of shear strength developed by Barton to determine the shear strength parameters of joint surfaces using a single test specimen. This approach is then applied to optimize the analysis of multiple specimens. An analysis of experimental results verifies that the shear strength parameters of joint surfaces obtained by the proposed method can more accurately reflect the shear mechanics of multiple specimens than conventional multiple sample analyses; meanwhile, the results are reasonable and reliable. More importantly, the optimized method ensures the shear strength parameters are no longer affected by the sequence of specimens employed during shear test. The optimized analysis method eliminates the effect of differences between specimens and the influence of subjective factors on test results and therefore provides more realistic evaluations of shear strength parameters.

Shrinkage Cracking Resistance Property of Self-Compacting Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 383-387
Author(s):  
Xian Yu Jin ◽  
Chuan Qing Fu ◽  
Nan Guo Jin ◽  
Fan Ge ◽  
Yi Bing Zhao
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Design Theory ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Cracking Resistance ◽  
Shrinkage Cracking ◽  
Resistance Property ◽  
Mix Proportion

Based on the project requirement of a nuclear power plant, using the method of free shrinkage test and ring cracking test, shrinkage cracking resistance property of grade C35 and C50 self-compacting concrete (SCC) with the optimized mix proportion was studied. The test results between SCC and ordinary vibrated concrete afforded by nuclear power plant project with the same grade were compared. The results indicated that the shrinkage cracking resistance property of SCC is prior to the ordinary vibrated concrete with the same strength grade. This kind of SCC can satisfy the nuclear power plant project, also the test results can be a reference of SCC design theory.

Fiber-Optic Transmitter for Nuclear Power Plants

2004 ◽  
Author(s):  
Junichi Higashi ◽  
Shinichi Murakawa
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Fiber Optic ◽  
Optic Fiber ◽  
Test Results ◽  
Maintenance System ◽  
Fiber Technology ◽  
Fabry Perot ◽  
Validation Tests

A promising Fiber-Optic Differential Pressure (DP) Transmitter is under development in Flexible Maintenance System (FMS) Projects that supported by Ministry of Economic, Trade, and Industries of Japan. The object of FMS projects is to improve maintenance works at nuclear power plants with latest technology. The new DP Transmitter uses optic-fiber technology of Extrinsic Fabry-Perot Sensor and Fizeau White-Light Cross-Correlator. Validation tests were performed to evaluate the tolerance of the DP transmitter in Nuclear Power Plant conditions. General requirements of PWR are accuracy (repeatability and linearity) of within +/−0.5%, pressure-proof of maximum 17.16MPa, Irradiation of 100Gy, and temperature range of 10–50 degrees centigrade at normal condition. The test results show the new DP transmitter can be expected as the next generation instrumentation in Nuclear Power Plants.

Rheological Flow Study of Molten Weld Metal Using the Modified Casson Prediction Model

2011 ◽  
Vol 403-408 ◽  
pp. 491-495
Author(s):  
Joseph I Achebo
Keyword(s):  
Shear Stress ◽  
Weld Metal ◽  
Prediction Model ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Test Results ◽  
Upward Flow ◽  
Viscoplastic Flow ◽  
Flow Equations ◽  
Flow Study

This paper principally examines the flow pattern that occurs when molten weld metal droplets are detached from globule formations at the tip of an electrode and are thereafter transported to the weldpool. This viscoplastic flow study was done using the modified Casson prediction model which is based on the Newtonian Homogenous Flow equations. Both chemical and mechanical tests were done. The inclusions (Slag) were found to possess an upward flow of 3 ms-1. The mechanical test results show that the shear stress of 483.2 MPa, which exceeded a yield stress of 230 MPa, was responsible for the continuous slipping movement of the molten metal towards the center of the weld pool at a velocity of 1.2ms-1. The results obtained by the application of this model were validated by both computational and experimental results obtained by other researchers.

Sign in / Sign up

Export Citation Format

Share Document