scholarly journals Thermal Analysis and Selected Properties of CuNi2Si Alloy Used for Railway Traction

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4613
Author(s):  
Jarosław Konieczny ◽  
Krzysztof Labisz
Keyword(s):  
Thermal Analysis ◽  
Global Policy ◽  
Heat Treated ◽  
Railway Traction ◽  
Dta Analysis ◽  
Differential Thermal Analysis Analysis ◽  
The One ◽  
Electric Traction ◽  
Potentiodynamic Method ◽  
Temperature Aging

This paper investigates the effect of high-temperature aging (600 °C and 650 °C) on the microstructure and functional properties of copper CuNi2Si alloy. The paper also presents the results of elastomeric tests performed by means of the Gleeble 3800 heat and plastic treatment simulator, as well as DTA (Differential Thermal Analysis) analysis carried out for the investigated alloy aged for 1, 2, 4 and 7 h. Corrosion resistance tests were performed by means of the potentiodynamic method with Atlas Sollich Atlas 0531 potentiostat/galvanostat in a 3% sodium chloride solution. Based on the tribological tests, it was confirmed that the CuNi2Si alloy was solution heat treated from the temperature of 1000 °C and gradually aged at the temperature of 600 °C and 650 °C for 1–7 h, characterized by a stable wear resistance. The alloy aged at the temperature of 600 °C was characterized by a lower mass loss compared to the one aged at 650 °C. Based on the DTA analysis, it was found that for the alloy aged for 2, 4 and 7 h, at the temperatures of 401 °C, 411 °C and 412 °C, respectively, the decomposition of a supersaturated solid solution took place by spinodal transformation accompanied by a sequence of phase transitions DO22 [(Cu, Ni)3Si],→ δ-Ni2Si → (Cu, Ni)3Si. The results of these investigations have proved that the CuNi2Si alloy can be widely used for electric traction. The use of alloys that replace elements made entirely of copper and, in this way influencing its lower demand, is in line with the global policy of economical management of natural resources.

scholarly journals Hydrothermal treatment of sprout-damaged grain: I. Effects on the technological quality of wheat

1978 ◽  
Vol 50 (3) ◽  
pp. 240-253
Author(s):  
Christina Westermarck-Rosendahl ◽  
Hannu Salovaara
Keyword(s):  
Amylase Activity ◽  
The Other ◽  
Processing Conditions ◽  
Falling Number ◽  
Gluten Quality ◽  
Heat Treated ◽  
Technological Quality ◽  
The One ◽  
Increasing Temperature

Two sprout-damaged wheat lots with the falling number values of 91 and 65 were heat-treated by immersing the grain in water of temperatures of 80, 85, 90 and 100°C, followed by rapid chilling in water. The purpose of the treatment was to suppress the excess a-amylase activity in the outer layers of the kernels. The a-amylase activity following the treatment was measured by the falling number test. The increase in the falling number value was the greater the longer the treatment lasted and the higher the water temperature was. Processing lasting 30 sec at 80, 85, 90 and 100°C increased the falling number value of the one lot from 91 to 105, 117, 133 and 238 and of the other lot from 65 to 69, 70, 98, 163, respectively. As the falling numbers increased the wet gluten content of the samples decreased. These changes had a negative correlation. The gluten quality showed heat damage when the amount of gluten had dropped by about 5 and 2 precentage units in the lots with the falling numbers 91 and 65, respectively. This occurred at processing of the lot of better quality for 70, 20, 13 and 6 sec in the order of increasing temperature. The corresponding durations for the other lot were above 60, 30, 20 and 6 sec. During these treatments the falling number values rose from 91 to 104—129 and from 65 to 70—71. These results were confirmed by farinogram and extensigram determinations and by baking tests. The same processing conditions affected more severely the lot having the better initial quality than the lot with greater sprout damages.

scholarly journals Niemiecka wizja miejsca Rosji w multipolarnym świecie

2017 ◽  
pp. 19-37
Author(s):  
Piotr Madajczyk
Keyword(s):  
German Society ◽  
First Century ◽  
Global Policy ◽  
Euro Zone ◽  
The World ◽  
Recent Debate ◽  
Twenty First Century ◽  
Hybrid War ◽  
The One

The commonly held truth is that the attitude of German society and the German elite to Russia is different to the attitude of Poland. This is not entirely true because due to Russian policy, the Germans have become more critical of Russia in the twenty-first century than before. Germany, however, pursues a more global policy than Poland. As Russia and Germany are of great significance in Polish politics, it is important to question the German vision of Russia’s place in today’s multipolar world. This is all the more important given that Germany, as the strongest country in Europe and the one that stabilized the euro zone, has difficulty in defining its role in the international arena. It is only as a result of the recent debate about the hybrid war, that Germany has overcome its unilateral geo-economic perception of the world. It is clear that the Germans are facing a new challenge, which they have not been prepared for.

scholarly journals Determination of γ′+γ / γ Phase Boundary in Ni-Al-Cr System Using DTA Thermal Analysis

2016 ◽  
Vol 61 (1) ◽  
pp. 237-240 ◽  
Author(s):  
T. Maciąg ◽  
K. Rzyman
Keyword(s):  
Thermal Analysis ◽  
Phase Boundary ◽  
Solution Method ◽  
Intermetallic Phase ◽  
Paper Analysis ◽  
Phase Boundaries ◽  
Disordered Phase ◽  
Dta Analysis ◽  
Cr System

Mechanical properties at elevated temperature, in modern alloys based on intermetallic phase Ni3Al are connected with phase composition, especially with proportion of ordered phase γ′ (L12) and disordered phase γ (A1). In this paper, analysis of one key systems for mentioned alloys - Ni-Al-Cr, is presented. A series of alloys with chemical composition originated from Ni-rich part of Ni-Al-Cr system was prepared. DTA thermal analysis was performed on all samples. Based on shape of obtained curves, characteristic for continuous order-disorder transition, places of course of phase boundaries γ′+γ / γ were determined. Moreover, temperature of melting and freezing of alloys were obtained. Results of DTA analysis concerning phase boundary γ′+γ / γ indicated agreement with results obtained by authors using calorimetric solution method.

Plasma Sputtering and Optical Properties of Au/SiO2 Nano-Composite Films

2005 ◽  
Vol 475-479 ◽  
pp. 1571-1574
Author(s):  
Bo Ping Zhang ◽  
Li-Shi Jiao ◽  
Hiroshi Masumoto ◽  
Takashi Goto
Keyword(s):  
Deposition Time ◽  
Composite Films ◽  
Absorption Peak ◽  
Nano Particle ◽  
Sio2 Matrix ◽  
Nano Composite ◽  
Plasma Sputtering ◽  
Heat Treated ◽  
The One ◽  
No Absorption

Au/SiO2 nano-composite thin films with 3 to 65 vol% Au content were prepared by induction-coil-coupled plasma sputtering. Au particles dispersed in the SiO2 matrix can be prepared by controlling the deposition time of one Au layer and the thickness of the one SiO2 layer. The Au nano-particle dispersed Au/SiO2 multilayer with an uniform nano-layered microstructure showed the absorption peak at the wavelength of 560 nm. The heat-treated Au/SiO2 films containing 3 to 65 vol% Au showed absorption peaks at the wavelength of 540 to 560 nm, while no absorption peak was observed in the as-deposited multilayers containing more than 12 vol% Au.

Weldability of pipe grade polyethylenes as realized from thermal and mechanical properties assessments

2016 ◽  
Vol 36 (8) ◽  
pp. 853-860 ◽  
Author(s):  
Vahabodin Goodarzi ◽  
Zahed Ahmadi ◽  
Mohammad Reza Saeb ◽  
Farkhondeh Hemmati ◽  
Mehdi Ghaffari ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Molecular Weight ◽  
Aging Process ◽  
Pipe Production ◽  
Lamellar Thickness ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Injection Molded ◽  
The One

Abstract Since polyethylene (PE) has been widely accepted for the production of high-pressure fluid conveying pipelines, studies devoted to weldability of PE connections were always of major importance. In this study, two industrial PE grades designed for pipe production, namely PE80 and PE100, were injection molded, cut, and then welded as PE100-PE100, PE100-PE80, and PE80-PE80. The heat-welded joints were assessed by differential scanning calorimetry and tensile measurements. The results obtained from thermal and mechanical analyses were compared with equivalents for aged samples. Thermal analysis revealed that the melting point of the PE100-PE100 sample is obviously larger than the one for the PE80-PE80 joint, for the PE80 chains deteriorate the crystallization of PE100. Further, the PE80-PE80 sample showed the lowest lamellar thickness and crystalline molecular weight among the studied joints. The aging process was found to increase lamellar thickness and molecular weight, though in the PE100-PE100 sample such quantities very limitedly increased. The yield stress of aged joints was higher than that for just-prepared samples, while an inverse trend was seen for strain at break. From a practical viewpoint, the PE100-PE100 welds offer better properties.

Synthesis of Ultra-Fine ZrB2 Powder by Borothermal Reaction under High Heating Rate

2009 ◽  
Vol 66 ◽  
pp. 77-80 ◽  
Author(s):  
Ge Sun ◽  
Hao Wang ◽  
Wei Min Wang ◽  
Yu Cheng Wang ◽  
Zheng Yi Fu
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Heating Rate ◽  
Zirconium Oxychloride ◽  
Reduction Reaction ◽  
Average Crystalline Size ◽  
High Heating Rate ◽  
Heat Treated ◽  
High Heating ◽  
Borothermal Reduction

Ultra-fine zirconium diboride (ZrB2) powders have been synthesized by borothermal reduction reaction, using zirconium oxychloride (ZrOCl2•8H2O) as the precursors of zirconia. The thermodynamic variation in the amorphous ZrO2-B system was studied by thermogravimetric and differential thermal analysis (TG-DTA). The precursors containing amorphous ZrO2 and B were heat-treated under a high heating rate. It is shown that the borothermal reaction can be completed at a relatively low temperature (~950 °C) and short duration (~5 min) under a heating rate of 200 °C/min. The synthesized powders have an average crystalline size of 300 nm with oxygen content less than 2.62 wt%.

Design of Shape Memory Alloy Actuators

1992 ◽  
Vol 114 (2) ◽  
pp. 223-230 ◽  
Author(s):  
C. Liang ◽  
C. A. Rogers
Keyword(s):  
Thermal Analysis ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Constitutive Relations ◽  
Design Approach ◽  
One Dimensional ◽  
Design Case ◽  
The One ◽  
Transient Thermal ◽  
Capacitance Transient

This paper describes the design of shape memory alloy force and displacement actuators based upon the thermomechanical constitutive relations previously developed by the authors. Numerical simulations and design case studies are presented which show the utility and advantages of this method over design methods currently being used. The types of actuators described and analyzed include bias spring actuators, differential force actuators, and their hybrid systems. The design approach includes coupling between the one-dimensional thermomechanical constitutive relations and a lumped capacitance transient thermal analysis. The design approach described herein will provide a practical and convenient method for use in the design of shape memory alloy actuators.

Problems of development of traction drives with brushless traction motors for passenger electric locomotives

2020 ◽  
pp. 20-25
Author(s):  
Andrey Sergeevich Kosmodamianskiy ◽  
◽  
Vladimir Ivanovich Vorobyev ◽  
Mikhail Yuryevich Kapustin ◽  
Oleg Vasilyevich Izmerov ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Rotation Frequency ◽  
Axial Direction ◽  
Traction Drive ◽  
Traction Motors ◽  
Adaptability To Manufacture ◽  
Traction Drives ◽  
Conducting Research ◽  
The One ◽  
Electric Traction

The paper considers a problem of creation of new traction drives with brushless electric traction motors (ETM) for passenger locomotives. Analysis of drive designs revealed that the increase of power of induction motors through the increase of rotation frequency leads to the contradiction between requirements for the design reliability, on the one hand, and requirements for technological simplicity, on the other hand. In order to solve the contradiction it is necessary to use ETM designs that have enhanced torque and minimal dimensions in axial direction. It is established that ETM with disk rotor (axial magnetic flux) satisfy such requirements. The authors proposed an aggregate scheme of support-frame traction drives that include ETM with disk rotor, which allows significantly increasing the adaptability to manufacture and repairability of drive at preservation of reliability. As a result, the authors made a conclusion about the reasonability of conducting research and development work on creation of locomotive ETM with axial magnetic flux. The authors have submitted an application for a patent on the proposed design of traction drive.

Nanostructure of Fe-C Alloys Prepared by Arc Melting in Vacuum

2017 ◽  
Vol 45 ◽  
pp. 218-228
Author(s):  
V. Karoutsos ◽  
Odyseas Venetsanos ◽  
Dimitris Geralis ◽  
Panagiotis Poulopoulos ◽  
C. Politis
Keyword(s):  
Lamellar Spacing ◽  
Isothermal Transformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
Heat Treated ◽  
Mean Size ◽  
Carbon Mapping ◽  
The One ◽  
Treatment Procedures

Three different Fe-C alloys were prepared in vacuum using the arc melting method: hypereutectoid (1.4% C), eutectoid (0.76% C) and hypoeutectoid (0.4% C). Unlike commercial steels, which they always contain Mn and other impurities, our samples were prepared by using high quality powders (99.999 wt.%). The samples were heat-treated and then observed with optical and scanning electronic microscopy (Zeiss EVO MA10). Selected samples were tested by microidentation (microhardness test). After isothermal transformation at 350 °C fine bainite nanostructures were observed in the hypoeutectoid sample, the mean size of which was found to be 50 nm. With the eutectoid sample, following different heat treatment procedures different micro-and nanostructures were measured: pearlite lamellar spacing, spheroidized cementite particles, and martensite needles, whose mean size is 145 nm, 290 nm and 200 nm respectively. The nanostructure of hypereutectoid sample after isothermal transformation at 650 °C, reveals the eutectoid and proeutectoid cementite lamellas with a mean spacing of 390 nm. X-ray diffraction pattern of eutectoid sample indicated the existence of cementite (Fe3C) content which is also confirmed by carbon mapping of pearlite colonies performed with Energy Dispersive X-ray Spectroscopy. The Vickers hardness of the samples compares well to the one of corresponding commercial steels.

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