The linear thermal expansion of bulk nanocrystalline Al and SS304 at low temperature

2011 ◽  
Vol 406 (14) ◽  
pp. 2758-2762 ◽  
Author(s):  
S.G. Wang ◽  
R.J. Huang ◽  
Y. Mei ◽  
K. Long ◽  
L.F. Li ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Low Temperature ◽  
Linear Thermal Expansion ◽  
Bulk Nanocrystalline

Application of TMA for Rapid Evaluation of Low-Temperature Properties of Elastomer Vulcanizates

1979 ◽  
Vol 52 (4) ◽  
pp. 735-747
Author(s):  
D. W. Brazier ◽  
G. H. Nickel
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Low Temperature ◽  
Linear Thermal Expansion ◽  
Dimensional Change ◽  
Rate Of Change ◽  
Transition Range ◽  
Free Expansion ◽  
Wide Range ◽  
Scan Rate

Abstract Static thermomechanical analysis has been investigated as a method for determining the low-temperature properties of vulcanizates. Dimensional changes of a sample in free expansion, indentation, or tension are monitored as the sample is heated at a known and reproducible rate. The first derivative of the dimensional change is simultaneously recorded. TMA/DTMA data obtained in free expansion gives the linear thermal expansion coefficient at any temperature during the experiment. The glass transition is observed as a change in slope as in dilatometric determinations. In the indentation mode, the thermogram is the result of competition between thermal expansion and indentation. For tension measurements, the thermogram records the additive sum of thermal expansion and tensional strain development. For indentation and tension, the glass transition is obtained by a standard extrapolation method. A maximum in the DTMA thermogram is also observed which represents the maximum rate of change as the sample is heated through the glass transition range. The temperature of this maximum, Tgd, is characteristic of a vulcanizate. Variation in scan rate between 2 and 20°C/min has little effect on Tgo and no effect on Tgd. At 50°C/min, thermal gradient effects predominate. For a wide range of vulcanizates in tension or indentation, Tgo or Tgd versus the Gehman rigidity modulus gives a linear relationship. Exact temperature agreement is not observed because of differences in the experimental techniques. In blends, several Tgd values are observed. Plasticizer effects can either be observed by a shift in the Tgo or by a change in the thermogram profile, the extent of indentation and temperature range over which it occurs. The extent of indentation correlates with vulcanizate hardness as expected. The indentation of a rubber sample by a flat probe has been treated mathematically in the literature, and the determination of Young's modulus by TMA/DTMA is now being investigated. In conclusion, the ease of sample preparation and the rapidity of TMA/DTMA measurements offers a quick approach to assessing the low-temperature properties of vulcanizates. At 20°C/min scan rate, runs can be completed in as little as four minutes (80°C total scan) if the sample has a single transition.

Transformation behavior of yttria stabilized tetragonal zirconia polycrystal–TiB2 composites

2001 ◽  
Vol 16 (7) ◽  
pp. 2158-2169 ◽  
Author(s):  
B. Basu ◽  
J. Vleugels ◽  
O. Van Der Biest
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Low Temperature ◽  
Tetragonal Zirconia ◽  
Mechanical Analysis ◽  
Transformation Behavior ◽  
Thermal Expansion Data ◽  
Thermally Induced ◽  
First Time ◽  
Tetragonal Zirconia Polycrystal

The objective of the present article is to study the influence of TiB2 addition on the transformation behavior of yttria stabilized tetragonal zirconia polycrystals (Y-TZP). A range of TZP(Y)–TiB2 composites with different zirconia starting powder grades and TiB2 phase contents (up to 50 vol%) were processed by the hot-pressing route. Thermal expansion data, as obtained by thermo-mechanical analysis were used to assess the ZrO2 phase transformation in the composites. The thermal expansion hysteresis of the transformable ceramics provides information concerning the transformation behavior in the temperature range of the martensitic transformation and the low-temperature degradation. Furthermore, the transformation behavior and susceptibility to low-temperature degradation during thermal cycling were characterized in terms of the overall amount and distribution of the yttria stabilizer, zirconia grain size, possible dissolution of TiB2 phase, and the amount of residual stress generated in the Y-TZP matrix due to the addition of titanium diboride particles. For the first time, it is demonstrated in the present work that the thermally induced phase transformation of tetragonal zirconia in the Y-TZP composites can be controlled by the intentional addition of the monoclinic zirconia particles into the 3Y-TZP matrix.

Anomalous thermal expansion behaviors of wood under dry and low-temperature conditions

Holzforschung ◽  
2014 ◽  
Vol 68 (5) ◽  
pp. 567-574 ◽  
Author(s):  
Tsunehisa Miki ◽  
Hiroyuki Sugimoto ◽  
Yuzo Furuta ◽  
Ichinori Shigematsu ◽  
Kozo Kanayama
Keyword(s):  
Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Longitudinal Direction ◽  
Mechanical Analysis ◽  
Solid Wood ◽  
Compression Pressure ◽  
Thermal Expansion Behavior ◽  
Expansion Behavior ◽  
Dry Conditions ◽  
Anomalous Thermal Expansion

Abstract The thermal expansion behavior of dry solid wood was investigated by dynamic dilatometry and thermal mechanical analysis. Anomalous thermal expansion behavior was observed concerning the displacement change under a constant compression pressure, which was not previously reported. Wood submitted to temperatures below 0°C under dry conditions exhibited a large increment in the linear thermal expansion coefficient (CLTE) and a sudden drop in the CLTE around 50°C as well as above 130°C during heating. In subsequent cooling/heating processes, these anomalous behaviors remained at temperatures below 100°C, although less pronounced, and disappeared at temperatures above 100°C. These behaviors were clearly perceptible in the radial and tangential directions but not in the longitudinal direction. The CLTE depended strongly on the heat and moisture history of the samples and the effects are species-specific.

Low-Temperature Thermal Expansion of Zinc Oxide. Vibrations in Zinc Oxide and Sphalerite Zinc Sulfide

1971 ◽  
Vol 4 (4) ◽  
pp. 1314-1323 ◽  
Author(s):  
B. Yates ◽  
R. F. Cooper ◽  
M. M. Kreitman
Keyword(s):  
Zinc Oxide ◽  
Thermal Expansion ◽  
Low Temperature ◽  
Zinc Sulfide

Low-Temperature Thermal Expansion of Copper

1957 ◽  
Vol 108 (2) ◽  
pp. 278-280 ◽  
Author(s):  
R. O. Simmons ◽  
R. W. Balluffi
Keyword(s):  
Thermal Expansion ◽  
Low Temperature
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