Concept of Damage Monitoring after Grinding for Components of Variable Hardness
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): A. Mičietová, J. Pištora, Z. Durstová, M. Neslušan This paper deals with nondestructive magnetic evaluation of ground surfaces of chosen material hardness. The properties of prepared surfaces are studied with respect to the progressively worn grinding wheel. The nondestructive testing is based on the Barkhausen noise (BN) technique and obtained BN signals are supplemented by metallographic observations. The results show that the nature of thermal injury of the surfaces prepared by strongly worn grinding wheel significantly depen...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Nondestructive Magnetic Monitoring of Grinding Damage
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): M. Čilliková, B. Mičieta, M. Neslušan, D. Blažek This paper deals with investigation of surface damage induced by grinding operation on the rings made of 100Cr6 bearing steel of hardness 62HRC. Progressively developed grinding wheel wear is caused by using the series of identical rings while the surface properties of machined rings like a hardness, residual stresses, microstructure alterations and magnetic Barkhausen noise (BN) emissions are monitored as manifestations of increased thermal damage. The noninvasive observations ba...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Evaluation of Fatigue Crack Growth in α-Titanium Alloys
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): Osamu Umezawa, Makiko Hamada, Toshifumi Tatsumi The fatigue crack growth modeling that based on linear fracture mechanics under the Mode I condition provided a good estimate of the stress intensity range for subsurface crack growth in α or near α-type titanium alloys. Based on the relationship between crack growth rate and stress intensity factor range, the fatigue crack propagating life was evaluated by the Paris rule. The subsurface crack initiation process consumed a large number of cycles to failure. Microstructure may strongly a...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Cyclic Bending Deformation and Fracture of Al and Al-1.0mass%Mg Alloy
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): Hayato Ikeya, Hiroshi Fukutomi The characteristics of cyclic bending deformation and fatigue fracture are studied on polycrystalline aluminum and Al-1.0mass%Mg alloy from the metallurgical point of view. It is found that the fatigue life mainly depends on grain size and the kind of materials. Cracks are preferentially formed at grain boundaries inclined 40 – 60°to the tension-compression direction, suggesting that shear stress affects the crack formation. EBSD measurements reveal the inhomogeneity of deformation. Intense development o...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Proximity Factor on Transformation from Subsurface to Surface Flaw
The objective of the paper is to reveal the proximity factor from the stress intensity factor interaction between the subsurface flaw and the free surface. (Source: Procedia Materials Science)
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Including of Ratio of Fatigue Limits from Bending and Torsion for Estimation Fatigue Life under Cyclic Loading
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): Marta Kurek, Tadeusz Łagoda The paper presents the estimation of the fatigue life under multiaxial cyclic loading of selected construction materials: two aluminum alloys PA4 (6068) and PA6 (2017A), alloy steel S355JOWP (in past called 10HNAP) and cast iron GGG 40. Calculations were based on three criteria of multiaxial fatigue, which is based on the concept of critical plane and the coefficients present in the expressions for the equivalent stresses are calculated on the basis of classical fatigue limits. (Source: Procedia Materials Science)
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Collapse Evaluation of Double Notched Stainless Pipes Subjected to Combined Tension and Bending
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): Ryosuke Suzuki, Masaaki Matsubara, Seiji Yanagihara, Mitsugu Morijiri, Atsushi Omori, Takashi Wakai In order to simplify the structural integrity assessment of double cracked stainless steel piping, plastic collapse stress of asymmetric double notched pipes subjected to combined tension and bending was investigated. The experimental plastic collapse stress of the asymmetric double notched pipe is compared with the theoretical plastic collapse stress of the single notched pipe. The experimental plastic collapse points were over th...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
The Current Status of New Czech Corrosion Fatigue Evaluation Proposal for WWER Nuclear Power Plants
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): Libor Vlček Presented paper introduces an innovative principle of fatigue life assessment suggested for WWER nuclear power plants. The subject of this work is to take into account the corrosion environment influence in actual methodology of low-cycle fatigue (LCF) assessment and prediction. The aim of this paper is to summarize the current status of the Czech proposal of corrosion fatigue assessment and prediction. The first project focused on base steel materials, which are used in primary circuit of WWER-440, started in 2010. The basic ...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Decreasing Thermal Stresses in Steam Generator Collector Weld's Area Using External Cooling
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): Roman Krautschneider, Lukas Joch Numerous WWER-440 steam generators showed a very serious problem of cracking in weld joints which are connecting primary collectors to the steam generator's vessel. As a cause of this cracking was determined stress corrosion cracking mechanism. The weld is connecting austenitic steel collector to the carbon steel vessel, so it is a dissimilar metal weld. There are two approaches how to lower the possibility of stress corrosion cracking in the weld. First one is to improve the secondary water chemistry in ...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Characterization of Reactor Pressure Vessel Steel by ABI Testing
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): Petr Haušild, Jan Siegl, Aleš Materna, Miloš Kytka, Radim Kopřiva Microstructure of the base metal, the multilayer welding seam and the two-layer cladding was characterized through the thickness of the WWER 440 reactor pressure vessel wall. Mechanical properties were determined by performing a series of instrumented indentations across the weld at room temperature. The results were treated by so-called automated ball indentation technique. Mechanical properties obtained by instrumented indentation from the local stress-strain b...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
The Evaluation of Actual Material Properties of Low Alloy CrMoV Steel from the Results of Small Punch Tests
Publication date: 2016 Source:Procedia Materials Science, Volume 12 Author(s): Karel Matocha, Ladislav Kander, Ondřej Dorazil, Kaishu Guan, Yifen Xu The Small Punch (SP) test technique is used for the evaluation of actual tensile, fracture and creep characteristics of materials exposed for a long period in operating plant components in order to provide data needed for plant life and integrity assessment. In the present paper the results of SP tests in the temperature range from -193°C to +20°C, carried out in two laboratories on low alloy steel of type 14MoV6-3 in as received state and after long term oper...
Source: Procedia Materials Science - May 5, 2016 Category: Materials Science Source Type: research
Prepartion and Characterization of Superparamagnetic Chitosan Coated Maghemite (γ-Fe2O3) for Gene Delivery
Publication date: 2015 Source:Procedia Materials Science, Volume 11 Author(s): Z. Sohrabijam, A. Zamanian, M. Saidifar, A. Nouri Maghemite ( –Fe 2 O 3) nanoparticles have been synthesized successfully with controlled co-precipitation technique with ultrasonic. The crystal sizes determined by Drbye - Scherre equation with XRD data were found close to the particle sizes calculated from TEM images, and this indicates that the synthesized particles are nanocrystalline. FT-IR was used to characterize the chitosan coated nanoparticles, and it was found that chitosan coated maghemite nanoparticles were synthesized....
Source: Procedia Materials Science - November 8, 2015 Category: Materials Science Source Type: research
Periodically Grown Quantum Nanostructures with Arbitrary Geometries: Periodicity Effects on the Induced Electro-elastic Fields
In this study, by utilization of the electro-mechanical eigenfield concept in conjunction with the Fourier series technique, an analytical solution is presented which gives the electro-elastic fields induced by one-, two-, and three-dimensional periodic distribution of QWs, QWRs, and QDs, respectively. This methodology takes into account the electro-mechanical couplings of elastic and electric fields within the piezoelectric barrier as well as the interaction between periodically grown QWRs and QDs. The latter would be so important since the density of the periodically grown QNSs will have significant effects on the induce...
Source: Procedia Materials Science - November 8, 2015 Category: Materials Science Source Type: research
Graphene-Based Terahertz Waveguide Amplifier
Publication date: 2015 Source:Procedia Materials Science, Volume 11 Author(s): O. Abbaszadeh Azar, M. Abdi, H. Baghban Graphene has been considered as an ideal material for electronic applications because of its high carrier mobility and thermal properties. Here, we study the conductivity of graphene at terahertz (THz) frequency range. Light can tune the conductivity of graphene and it has been shown that optically pumped multiple graphene layer (MGL) presents negative conductivity in THz region due to inter-band population inversion. With use of this property THz travelling-wave amplifier based on optically pump...
Source: Procedia Materials Science - November 8, 2015 Category: Materials Science Source Type: research
Characterization and Synthesis of Magnetite Nanoparticles by Innovative Sonochemical Method
In this study, in order to obtain nanoparticles with narrow size distribution and united shape, reverse coprecipitation method was done under ultrasound. Structural analysis was done using XRD and FTIR. The XRD result was analyzed using Scherrer method and formation of spinel structure with was confirmed. The crystallite size and lattice parameters were calculated 17.7nm and 8.358°A respectively. FTIR peaks were observed in wave number and confirms the structure. Magnetic properties of the MNPs was studied using VSM and the saturation magnetization (M s ) and the coercive field of the MNPs is 63.13emu/g and 9.10e r...
Source: Procedia Materials Science - November 8, 2015 Category: Materials Science Source Type: research
