Calibration of the differential dilatometric measurement signal upon heating and cooling; thermal expansion of pure iron

2004 ◽  
Vol 413 (1-2) ◽  
pp. 215-225 ◽  
Author(s):  
Y.C Liu ◽  
F Sommer ◽  
E.J Mittemeijer
Keyword(s):  
Thermal Expansion ◽  
Pure Iron ◽  
Dilatometric Measurement ◽  
Heating And Cooling ◽  
Measurement Signal

Thermo-Mechanical Analysis of Chosen Epoxy Resins Used in Aviation Technology

2015 ◽  
Vol 1126 ◽  
pp. 187-193
Author(s):  
Kamil Prusak ◽  
Janusz Zmywaczyk ◽  
Piotr Koniorczyk ◽  
Jan Godzimirski ◽  
Marcin Cegła
Keyword(s):  
Thermal Expansion ◽  
Epoxy Resins ◽  
Loss Modulus ◽  
Testing Machine ◽  
Mechanical Analysis ◽  
Stress Strain ◽  
Temperature Range ◽  
Heating And Cooling ◽  
Tan Δ ◽  
Material Testing Machine

In this paper the results of storage modulus (E’), loss modulus (E’’) and damping parameter tan (δ)=E''/E' of epoxy resins Epidian 57 and L285 with curing agents Z1 and LH285, respectively are presented. In addition to this the stress-strain and thermal expansion characteristics of Epidian 53, 57 and L285 were obtained experimentally in order to compare Dynamic Mechanical Analysis (DMA) results. Temperature range of DMA investigations using Netzsch (Germany) DMA 242C analyzer was from-120 °C to +110 °C at the heating rate of 1 K/min with frequency of {0.1, 1, 10} Hz, respectively. Netzsch DIL 402C dilatometer was used to study the thermal expansion of the tested samples within temperature range from 30 °C to 80 °C at 1 K/min of heating and cooling rates, respectively and Huang TA computer servo control material testing machine HT-2402 was applied to determine the stress-strain characteristics. Measurements of sample elongation ΔL and physical α* were performed twice in heating and cooling cycles. The glass transition temperature Tg determined from maximum of tan (δ) curve at f = 1Hz was equal to 76.7 °C for E57 and 87.2 °C for L285. It has been observed durable deformed shape of L285 sample with deflection in the middle about 5 mm just after finishing the DMA first run of heating which significantly affected DMA results during the second run of heating

Effect of Temperature Cycles on the Critical Current Density of YBa2Cu3O7-δ

1987 ◽  
Vol 99 ◽  
Author(s):  
T. H. Tiefel ◽  
S. Jin ◽  
R. C. Sherwood ◽  
R. A. Fastnacht ◽  
S. Nakahara ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Strong Field ◽  
Effect Of Temperature ◽  
Weak Links ◽  
Zero Field ◽  
Transmission Electron Microscopy Analysis ◽  
Temperature Cycles ◽  
Heating And Cooling ◽  
Transmission Electron ◽  
Electron Microscopy Analysis

ABSTRACTThe transport Jc of the polycrystalline YBa2Cu3O7-δ superconductor seems to be dominated by weak links between high Jc regions as evidenced by low Jc values and their strong field dependence. The possible effects of thermal expansion-contraction and the tetragonal-orthorhombic transformation on the weak links and the Jc values were investigated by repeated thermal cycling of sintered pellets between -196°C and various high temperatures (600–850°C) using a furnace heating and cooling in an oxygen atmosphere. While more than a five-fold decrease in Jc from -400 to -70 A/cm2 (at 77K in zero field) is observed after 5 temperature cycles between -196'C and 850°C, only a slight decrease (to -370 Atm2) is noticed after 5 cycles between -196*C to 600°C, the temperature span of which is not all that much smaller than the former cycles. Transmission electron microscopy analysis clearly indicates that the drastic deterioration in Jc by repeated phase transformation is caused by increased amount of microcracks on (001) basal planes near the grain boundaries. The results will be discussed in terms of the large thermal expansion anisotropy of this layer-structured compound.

Transient Heat Conduction and Thermal Coefficient of Ceramic Coated Fabrics

2014 ◽  
Author(s):  
Khashayar Teimoori ◽  
Ali M. Sadegh
Keyword(s):  
Thermal Expansion ◽  
Heat Conduction ◽  
Coefficient Of Thermal Expansion ◽  
Transient Heat Conduction ◽  
Thermal Coefficient ◽  
Plate Temperature ◽  
Nonwoven Fabrics ◽  
Heating And Cooling ◽  
Set Up ◽  
Coated Fabrics

Ceramic coated fabrics have been employed for heat resistant clothing such as fire-fighters gears, fire-proof insulators, and heating and cooling insulators. Thus, transient heat conduction and thermal properties of such fabrics are needed for the design of the clothing. The goal of this study is to measure the transient heat conduction and the coefficient of thermal expansion of ceramic coated fabrics with different woven morphologies. This has been accomplished through an experimental setup consists of a hotplate assembly, applying a uniform temperature, with the accuracy of +/− 1 °C in less than 500 msec, a ceramic coated fabric and an infra-red thermometer assembly. This set up has been validated by using a known material such as aluminum and copper for the coefficient of thermal expansion measurement. The hot plate temperature was varied between 30 to 400°C within 300 seconds. The transient heat conduction and the thermal coefficient of the woven ceramic coated fabrics were compared with ceramic nonwoven fabrics materials. Finally, upon comparing different samples and measuring the coefficients of thermal expansion, K’s, the level of delay in heat transfer with respect to time has been determined.

Dilatometric Measurement of the Thermal Expansion of Cobalt Single Crystal

1981 ◽  
Vol 20 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Yoshitaka Kasamatsu ◽  
Michie Koyama ◽  
Kan-ichi Masumoto ◽  
Ken-ichi Kojima ◽  
Tadamiki Hihara ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Single Crystal ◽  
Dilatometric Measurement

Research on the Apparent Thermal Expansion Coefficient of Concrete Subject to Freeze-Thaw Cycles and Chloride Salt Attack

2012 ◽  
Vol 446-449 ◽  
pp. 3304-3310 ◽  
Author(s):  
Zhen Di Wang ◽  
Yan Yao ◽  
Ling Wang
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Chloride Salt ◽  
Absolute Value ◽  
Freeze Thaw ◽  
Heating And Cooling ◽  
Water To Cement Ratio ◽  
Temperature Rate ◽  
Concrete Matrix

The aim of the research is to determine the strain-temperature rate and investigate the apparent thermal expansion coefficient of three kinds of concrete (ATEC). The strain of concrete with the dimension of 100mm×100mm×100mm subject to freeze-thaw cycles and chloride salt attack were measured using an embedded strain gauge. The ATEC was calculated from the strain-temperature rate using linear regression. The results show that the absolute value of ATEC of specimen saturated by 3.5 wt. % chloride salt solution was reducing with the progress of freeze-thaw cycles. However, the ATEC of the dried specimen subject to heating and cooling is independent from water to cement ratio, and approximately maintains the same level during the whole heating and cooling cycle, and the ATEC of air-entrained specimen is constant within 20 cycles. Overall, deterioration of concrete matrix can be evaluated by apparent thermal expansion coefficient besides weight loss and dynamic elastic modulus.

Regularities of the thermal expansion of cladding tubes and rods from E110opt alloy in the temperature range 273-1473 K (20-1200°C)

2020 ◽  
Vol 4 ◽  
pp. 51-64
Author(s):  
M.G. Isaenkova ◽  
◽  
A.V. Tenishev ◽  
Yu.A. Perlovich ◽  
S.D. Stolbov ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Phase Transformations ◽  
Orientation Dependence ◽  
Internal Stresses ◽  
Layer By Layer ◽  
Temperature Range ◽  
Heating And Cooling ◽  
Expansion Coefficients ◽  
Analytical Expressions ◽  
Tangential Directions

The regularities of the thermal expansion of cladding tubes and rods from the E110opt alloy, as well as the anisotropy of their thermal properties in the case of layer-by-layer texture inhomogeneity are studied. The thermal linear expansion coefficients (TLEC) of rods and cladding tubes were measured in the axial, radial and tangential directions during heating and cooling in the temperature range of 293-1473 K (20-1200°C). It is shown that as a result of a→b→a phase transformations in the samples, a stable texture of phase transformations is formed which is preserved during subsequent heating and cooling cycles. Analytical expressions are obtained that describe the temperature dependence of the thermal expansion coefficient in the first cycle of heating products from the E110opt alloy, taking into account possible a→b phase transformations and the resulting a-Zr crystal lattice deformation along the a and c axes. It was established that the presence of layer-by-layer inhomogeneity in the samples leads to the appearance of stresses between layers with different crystallographic textures and, as a result, affects the orientation dependence of phase transformations that are sensitive to the stress state in the material. The results obtained indicate the need to take into account the internal stresses arising in textured anisotropic materials during heating and cooling, and to separate the contributions of thermal expansion and plastic deformation when analyzing data from dilatometric measurements of sample sizes.

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