Mechanical Properties

1983 ◽  
pp. 237-267
Author(s):  
D. T. Read
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Mechanical Behavior ◽  
Low Temperatures ◽  
Metals And Alloys ◽  
Cryogenic Temperatures ◽  
Temperature Dependent ◽  
Test Procedures

Abstract The mechanical properties of a material describe the relations between the stresses acting on the material and its resulting deformations. Stresses capable of producing permanent deformations, which remain after the stresses are removed, are considered in this chapter. The effects of cryogenic temperatures on the mechanical properties of metals and alloys are reviewed in this chapter; the effects on polymers and glasses are discussed briefly. The fundamental mechanisms controlling temperature-dependent mechanical behavior, phenomena encountered in low-temperature testing, and the mechanical properties of some representative engineering metals and alloys are described. Modifications of test procedures for low temperatures and sources of data are also included.

Electrical Properties

1983 ◽  
pp. 163-201
Author(s):  
F. R. Fickett
Keyword(s):  
Electrical Properties ◽  
Low Temperature ◽  
Low Temperatures ◽  
Metals And Alloys ◽  
Cryogenic Temperatures

Abstract This chapter presents topics pertaining to resistance at cryogenic temperatures: measurement, the resistive mechanisms, and available data. The chapter also presents brief descriptions of the various mechanisms that are operative in producing resistance at low temperatures. The alloys discussed are the nondilute mixtures of metals. An introduction to low-temperature electrical properties of specific metals and alloys is included.

Compressive Plasticity of Zr-Based Bulk Metallic Glass at Low Temperature

2012 ◽  
Vol 443-444 ◽  
pp. 583-586
Author(s):  
Ya Juan Sun ◽  
Ri Ga Wu ◽  
Hong Jing Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Low Temperatures ◽  
Room Temperature ◽  
Shear Bands ◽  
Strain Curve ◽  
Testing Temperature ◽  
Stress Strain Curve

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.

Low-Temperature (<300°C) Phosphate Ceramics from Reactive Aluminas

1989 ◽  
Vol 179 ◽  
Author(s):  
M. R. Silsbee ◽  
R. A. Steinke ◽  
D. M. Roy ◽  
D. K. Agrawal ◽  
R. Roy
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Low Temperatures ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Characterization Techniques ◽  
Exciting Potential

AbstractReactive aluminas, including rapidly calcined gibbsites, offer exciting potential for forming ceramic materials at low temperatures. New x-ray amorphous aluminas will react with water at room temperatures to form compacts with 10–50 MPa tensile strengths, via viscous slurries. The cementious behavior of these materials has been examined. The results of TGA, x-ray diffraction, SEM, mechanical properties, and other characterization techniques, as applied to these systems, will be discussed.

Experimental and Numerical Simulation of the Mechanical Behavior of Stratospheric Balloons Materials

2008 ◽  
Vol 33-37 ◽  
pp. 597-602
Author(s):  
Pierre Vialettes ◽  
Lina Zhou ◽  
Bing Pan ◽  
Zhuo Zhuang
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Low Temperature ◽  
Mechanical Behavior ◽  
Future Development ◽  
Earth Observation ◽  
Tsinghua University ◽  
First Results ◽  
Experimental Facilities ◽  
Manufacture Company

The school of aerospace of Tsinghua University has started a project to develop new kind of stratospheric balloons for earth observation. These balloons will be designed to stand in the same position during a few days at 20 kilometers of altitude. To reach this goal, the first step is to select adapted materials for the balloon envelope. The materials for stratospheric balloons application should have specific properties adapted to the environment such as mechanical, thermo-optical, and permeability properties. Thus, we have asked a material manufacture company to develop and manufacture a material adapted to our application. In this paper, we will present the first results concerning the mechanical properties of the material. Experimental facilities have been developed to test the mechanical behavior of the materials at room and low temperature. The future development of the project will be to identify behavior law adapted to our material that fits with the experimental results.

SPIN FLUCTUATIONS IN TCo2 STUDIED BY RESISTIVITY AND THERMOPOWER EXPERIMENTS (T = Y, Lu, Sc, Hf, Zr, Ce)

1993 ◽  
Vol 07 (01n03) ◽  
pp. 370-373 ◽  
Author(s):  
N. BARANOV ◽  
E. BAUER ◽  
E. GRATZ ◽  
R. HAUSER ◽  
A. MARKOSYAN ◽  
...  
Keyword(s):  
Low Temperature ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Temperature Region ◽  
Low Temperatures ◽  
Spin Fluctuations ◽  
General Tendency ◽  
Electronic Specific Heat ◽  
Temperature Dependent

The temperature dependence of the resistivity and the thermopower in the region from 4.2K up to 1000K for the six isostructural paramagnetic compounds TCo 2 (T=Y, Lu, Sc, Hf, Zr, Ce) is studied. The resistivity ρ (T) follows a T 2 dependence at low temperatures in all these compounds. Plotting the A values into an A vs. γ2 diagram shows that YCo 2, LuCo 2, and ScCo 2 are spinfluctuation systems (A and γ denote the coefficients in ρ (T) = ρ0 + AT 2 and that of the electronic specific heat, respectively) HfCo 2 and ZrCo 2 do not fit into this general tendency in the ( A , γ2)-diagram. The temperature dependent thermopower S(T) in YCo 2, LuCo 2 and ScCo 2 exhibits a pronounced minimum in the low temperature region. These minima are obviously connected with the existence of spin fluctuations (paramagnon-drag). Spin fluctuations in HfCo 2 and ZrCo 2 are less important. This we conclude also from the ten times smaller A-values and the missing minimum in the thermopower at low temperatures.

Weak Localization Effects in Fluorineintercalated Graphite Fibers

1990 ◽  
Vol 209 ◽  
Author(s):  
S.L. Di Vittorio ◽  
M.S. Dresselhaus ◽  
V. Bayot ◽  
L. Piraux ◽  
J-P. Issi ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Low Temperatures ◽  
Weak Localization ◽  
Temperature Dependent ◽  
Weak Magnetic Fields ◽  
Graphite Fibers ◽  
Temperature Dependent Resistivity ◽  
High Fields ◽  
Hole Interaction

ABSTRACTThe intercalation of fluorine into graphite introduces defects into the highly crystalline pristine fibers. These defectsare studied using temperature-dependent resistivity and magnetoresistance measurements. A logarithmic increase in resistivity at low temperature is observed, whereas the high temperature behavior is metallic. At weak magnetic fields and low temperatures, a negative magnetoresistance is observed, which becomes positive at high fields. These effects are explainedusing the two theories of weak localization and hole-hole interaction. In the light of TEM pictures of the microstructure of the fluorinated fibers, the origin of the defects in the intercalated fibers is discussed.

scholarly journals Low-Temperature Induced Martensitic Transformation Enhancing Mechanical Properties of Metastable Fe-Ni-P Alloy

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 785
Author(s):  
Cui ◽  
Jiang ◽  
Zhang ◽  
Liu
Keyword(s):  
Mechanical Properties ◽  
Martensitic Transformation ◽  
Low Temperature ◽  
Strain Hardening ◽  
Low Temperatures ◽  
Cryogenic Treatment ◽  
Great Promise ◽  
Compressive Yield Strength ◽  
High Plasticity ◽  
Face Centered Cubic

The metastable Fe-Ni-P alloy with phosphorus (P) solid-solution structure has been fabricated by spark plasma sintering. Its face-centered cubic (FCC) matrix without the precipitation of phosphide attains a high plasticity and an excellent strain hardening ability at room temperature. This Fe-Ni-P alloy is subjected to cryogenic treatment at various temperatures (−20 °C and −50 °C), to investigate the role of phosphorus on the microstructural evolution and mechanical properties of γ-(Fe-Ni) alloy at low temperatures. The results indicate that the addition of phosphorus can destabilize the Fe-Ni-P alloy and facilitate its martensitic transformation during cryogenic treatment. P-doping does not lead to obvious embrittlement of Fe-Ni-P alloy at low temperatures, but strengthens the alloy by promoting microstructure evolution. The Fe-Ni-P alloy has high plasticity and good strain hardening ability after treated at −20 °C, and is converted to acicular martensite structure after being treated at −50 °C, resulting in a significant increase in its hardness (433 HV) and compressive yield strength (1271 MPa). Developing this Fe-Ni-P alloy as a load-bearing component for low-temperature conditions shows great promise.

Mechanical Behavior of Quasicrystals

MRS Bulletin ◽  
1997 ◽  
Vol 22 (11) ◽  
pp. 65-68 ◽  
Author(s):  
Knut Urban ◽  
Michael Feuerbacher ◽  
Markus Wollgarten
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
High Temperature ◽  
Low Temperature ◽  
Mechanical Behavior ◽  
Melting Temperature ◽  
Sliding Friction ◽  
Great Promise ◽  
Brittle To Ductile Transition ◽  
Physical Reasons

Scientists have studied the mechanical properties of quasicrystalline materials for quite some time. However the difficulty in obtaining material of reasonable quality hampered systematic investigations. The progress in materials preparation in recent years has triggered new activity in this field. Furthermore the new ternary and multicomponent alloys have demonstrated great promise for use as coatings with good wear resistance and low coefficients of sliding friction. However the physical reasons for these properties and their correlation with the particular structure of quasicrystals are still not understood. As in conventional alloys, experiments under well-defined conditions are required that can serve as a basis for understanding the intrinsic mechanical properties of quasicrystals. Such studies are now increasingly possible after the development of techniques to grow larger single quasicrystals up to a few centimeters in size directly from the melt.Since the mechanical behavior of quasicrystalline alloys is to a great extent determined by a brittle-to-ductile transition at about 70% of the absolute melting temperature, it is useful to discuss the mechanical properties with reference to appropriately defined low-temperature and high-temperature regions.

The Effect of Homogenization and Interrupted Rolling on Microstructure and Properties of Zn-Cu-Ti Rolled Sheets

2016 ◽  
Vol 682 ◽  
pp. 380-386
Author(s):  
Piotr Osuch ◽  
Monika Walkowicz ◽  
Tadeusz Knych ◽  
Andrzej Mamala
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Dynamic Recrystallization ◽  
Low Temperatures ◽  
Rolling Process ◽  
Ti Alloy ◽  
Temperature Performance ◽  
Roofing Material ◽  
Technological Route ◽  
Rolling Stage

Due to specific application of the Zn-Cu-Ti alloy rolled sheets as a roofing material, ready-made sheets has to meet some specific requirements of bendability at relatively low temperatures, as low as 5°C. In the current paper it was shown that susceptibility of the Zn-Cu-Ti sheets to low temperature bending, is closely related to degree of its dynamic recrystallization during rolling process. The paper discusses effect of different technological routes on the microstructure, mechanical properties and in particular the low temperature performance of Zn-Cu-Ti rolled sheets. The experimental results shows that the homogenization of Zn-Cu-Ti casted strips at the pre-rolling stage can play important role in recrystallization of the sheets during rolling. The current work is part of research on designing new technological route.

scholarly journals Testing and Applications of Non-Linear Wave Shaping Circuits Based on Zener Diodes at Cryogenic Temperatures

2017 ◽  
Vol 13 (4) ◽  
pp. 4910-4918
Author(s):  
A. M. Abd El-Maksood
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
The Other ◽  
Electronic Systems ◽  
Linear Wave ◽  
Cryogenic Temperatures ◽  
Temperature Variations ◽  
Wide Range ◽  
Non Linear ◽  
The Stability

            Applications of wave-shaping clipping circuits based on Zener diodes are of great interest in a wide range of modern electronic systems. As well, given the strong interest in space research and trips to distant planets, where the journey takes long periods. Therefore, the matter requires reliance on electronic systems with special specifications commensurate with the nature of the extremely low-temperature environments, down to cryogenic level (around 90 K). So, the present paper was concerned with studying the stability of the performance of different non-linear wave-shaping systems, based on silicon Zener diodes, whenever operates at very low temperatures down to cryogenic levels. From which, it is clear that for BZX79-C4V7 and BZX79-C5V6 Zeners, such electronic systems were shown to be insensitive to temperature variations. On the other hand, low breakdown voltage Zeners (BZV86-1V4 and BZX83-C3V6), the clipping edges were shown to be increased with lowering temperatures from 300 K down to 93 K. Finally, for Zener diodes with VZ greater than 6.0 V (BZX83-C6V8 and BZX55C9V1), the temperature coefficient is positive, so the clipping edges decrease with lowering temperatures, for the same range of temperatures.

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