High-Temperature Compression Testing of Graphite

1953 ◽  
Vol 20 (2) ◽  
pp. 289-294
Author(s):  
Leon Green

Abstract Experiments on the compression of graphite cylinders at elevated temperatures are described. It is found that the short-time compressive strength increases with temperature in the range from room temperature to 2000 C, a variation which is consistent with the previously reported behavior of the tensile strength. Photographs of typical modes of deformation and their corresponding stress-strain curves are presented, but a limited degree of temperature control renders the curves semiquantitative in nature. The large, mutually opposing influences of temperature and strain rate are illustrated by photographs of typical failures, and stress-relaxation curves manifest the plasticity of graphite at high temperatures.

2011 ◽  
Vol 462-463 ◽  
pp. 1-6 ◽  
Author(s):  
Tao Suo ◽  
Yu Long Li ◽  
Ming Shuang Liu

As Carbon-fiber-reinforced SiC-matrix (C/SiC) composites are widely used in high-temperature structural applications, its mechanical behavior at high temperature is important for the reliability of structures. In this paper, mechanical behavior of a kind of 2D C/SiC composite was investigated at temperatures ranging from room temperature (20C) to 600C under quasi-static and dynamic uniaxial compression. The results show the composite has excellent high temperature mechanical properties at the tested temperature range. Catastrophic brittle failure is not observed for the specimens tested at different strain rates. The compressive strength of the composite deceases only 10% at 600C if compared with that at room temperature. It is proposed that the decrease of compressive strength of the 2D C/SiC composite at high temperature is influenced mainly by release of thermal residual stresses in the reinforced carbon fiber and silicon carbon matrix and oxidation of the composite in high temperature atmosphere.


1951 ◽  
Vol 18 (4) ◽  
pp. 345-348
Author(s):  
Leon Green

Abstract The fatigue properties of grade AUF extruded polycrystalline graphite were investigated at ambient and elevated temperatures. Specimens cut parallel to the axis of extrusion were stressed in reversed bending at room temperature and at 3550 F. The endurance limit of this graphite was found to increase from 2500 psi at room temperature to about 4400 psi at 3550 F. The increase in endurance limit is correlative with the increase in short-time tensile strength with temperature observed in earlier studies of graphite.


Alloy Digest ◽  
1965 ◽  
Vol 14 (8) ◽  

Abstract SAP is a special Sintered Aluminum Powder characterized by high tensile strength at room temperature and at elevated temperatures. It features a range of useful engineering properties. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, machining, joining, and powder metal forms. Filing Code: Al-146. Producer or source: Aluminium Industrie Atkiengesellschaft.


1950 ◽  
Vol 23 (2) ◽  
pp. 338-346 ◽  
Author(s):  
B. S. T. T. Boonstra

Abstract It is necessary to determine the physical properties of rubbers at relatively high temperatures when products made from them are to be used at such temperatures in actual service. The term heat aging is used when the vulcanizate is tested at room temperature, exposed to elevated temperatures for given periods of time, and then tested again at room temperature. The term high-temperature strength is proposed for values obtained when the vulcanizates are tested at the actual higher service temperatures. Effective comparison of natural and synthetic rubbers is best obtained by determining tensile product values, which are the result of the combining of tensile strength and elongation values. In the evaluating of vulcanizates of tire compounds of various rubbers, another factor must be taken into account. Synthetic-rubber tires develop more heat in service than do natural-rubber tires, and the former therefore generally operate at higher temperatures than do the latter. Synthetic-rubber tires therefore require a greater high temperature strength than do natural rubber tires, but, as has been shown, synthetic rubbers actually have a lower high-temperature strength. The part played by carbon black with respect to the tensile properties of some synthetic rubbers is considered that of a substitute for crystallization in natural and other synthetic rubbers, which substitute does not, however, possess the same favorable features. Carbon black even in noncrystallizing rubbers does not increase strength; it merely shifts the optimum strength value to a higher temperature so that this temperature is in the room temperature range. The temperature coefficient of strength for Butyl and Neoprene rubbers is so large at room temperature that a few degrees' difference in temperature causes large changes in strength. The tensile strength and elongation at break of these two rubbers decrease sharply between 20 and 40° C.


2014 ◽  
Vol 611-612 ◽  
pp. 11-18 ◽  
Author(s):  
Toru Minote ◽  
Yoshimasa Funakawa ◽  
Naoko Saito ◽  
Mitsugi Fukahori ◽  
Hiroshi Hamasaki ◽  
...  

High tensile strength steel sheets have large springback after being formend at room temperature. Warm forming can be a solution to reduce springback of high tensile strength steel parts. NANOHITENTM is a high strength ferritic steel precipitation-strengthened by nanometer-sized carbides developed by JFE Steel Corporation. Tensile strength of the steel at room temperature does not change before and after deformation at elevated temperatures up to 873K since the carbides in the steel are stable at high temperatures less than 973K. Therefore, the steel is suitable for warm forming. Springback of 980MPa NANOHITENTM parts warm formed at 873K is the same level of that of cold formed conventional 590MPa steel parts. In this study, two kinds of material testing at room temperature and at elevated temperatures between 573K and 937K were performed to understand the mechanical behavior of 980MPa NANOHITENTM: uniaxial tensile tests and bending tests. The steels flow stress depends on not only material temperature but also strain rate in uniaxial tensile tests. After a bending test, the specimen shows springback measured by the change of an angle between the two sides. Stress relaxation happens while a test specimen is held at the bottom dead point after bending. And the stress relaxation could be used to reduce springback of warm formed parts.


Alloy Digest ◽  
2005 ◽  
Vol 54 (12) ◽  

Abstract Wieland K-88 is a copper alloy with very high electrical and thermal conductivity, good strength, and excellent stress relaxation resistance at elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CU-738. Producer or source: Wieland Metals Inc.


Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.


Alloy Digest ◽  
1969 ◽  
Vol 18 (5) ◽  

Abstract Carpenter T-K is a tungsten-chromium type hot-work steel having good red-hardness and resistance to abrasion. It will withstand high operating temperatures up to 1000 F for long periods. It is recommended for hot shear blades, forging and extrusion dies, hot compression tools, and similar applications where high compressive strength and wear resistance at elevated temperatures are required. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-219. Producer or source: Carpenter.


2011 ◽  
Vol 261-263 ◽  
pp. 416-420 ◽  
Author(s):  
Fu Ping Jia ◽  
Heng Lin Lv ◽  
Yi Bing Sun ◽  
Bu Yu Cao ◽  
Shi Ning Ding

This paper presents the results of elevated temperatures on the compressive of high fly ash content concrete (HFCC). The specimens were prepared with three different replacements of cement by fly ash 30%, 40% and 50% by mass and the residual compressive strength was tested after exposure to elevated temperature 250, 450, 550 and 650°C and room temperature respectively. The results showed that the compressive strength apparently decreased with the elevated temperature increased. The presence of fly ash was effective for improvement of the relative strength, which was the ratio of residual compressive strength after exposure to elevated temperature and ordinary concrete. The relative compressive strength of fly ash concrete was higher than those of ordinary concrete. Based on the experiments results, the alternating simulation formula to determine the relationship among relative strength, elevated temperature and fly ash replacement is developed by using regression of results, which provides the theoretical basis for the evaluation and repair of HFCC after elevated temperature.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 510
Author(s):  
Seyed Esmaeil Mohammadyan-Yasouj ◽  
Hossein Abbastabar Ahangar ◽  
Narges Ahevani Oskoei ◽  
Hoofar Shokravi ◽  
Seyed Saeid Rahimian Koloor ◽  
...  

Polymer concrete contains aggregates and a polymeric binder such as epoxy, polyester, vinyl ester, or normal epoxy mixture. Since polymer binders in polymer concrete are made of organic materials, they have a very low heat and fire resistance compared to minerals. This paper investigates the effect of basalt fibers (BF) and alginate on the compressive strength of polymer concrete. An extensive literature review was completed, then two experimental phases including the preliminary phase to set the appropriate mix design, and the main phase to investigate the compressive strength of samples after exposure to elevated temperatures of 100 °C, 150 °C, and 180 °C were conducted. The addition of BF and/or alginate decreases concrete compressive strength under room temperature, but the addition of BF and alginate each alone leads to compressive strength increase during exposure to heat and increase in the temperature to 180 °C showed almost positive on the compressive strength. The addition of BF and alginate both together increases the rate of strength growth of polymer concrete under heat from 100 °C to 180 °C. In conclusion, BF and alginate decrease the compressive strength of polymer concretes under room temperature, but they improve the resistance against raised temperatures.


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