Heat-Resistant Corundum Concrete Reinforced with Aluminum Oxide Fibers Synthesized Within a Matrix During Firing. Part 1. Heat Resistance of High-Temperature Materials and Means of Improvement

2014 ◽  
Vol 55 (3) ◽  
pp. 223-226 ◽  
Author(s):  
V. N. Sokov ◽  
S. D. Sokova
2020 ◽  
pp. 31-37
Author(s):  
S.N. Semenova ◽  
◽  
A.M. Chaykun ◽  

A review of the scientific technical literature in the field of modern research on silicone rubber compositions with high temperature resistance, including those with fire-resistant properties, is presented. The polymer bases and heat-stabilizing and flame-retardant additives used in the developments, as well as methods for preparing rubber mixes and rubbers are shown. Features of compounding materials with a combination of heat resistance and fire-resistance are noted. The relevance of research for the needs of aviation equipment is shown.


2009 ◽  
Vol 147-149 ◽  
pp. 744-751 ◽  
Author(s):  
Józef Błachnio

Heat-resistant and high-temperature materials are used to manufacture components, devices, and systems operated at high temperatures, i.e. under severe heat loads. Gas turbines used in the power industry, the traction, marine, and aircraft engines, the aerospace technology, etc. are good examples of such systems. Generally, as the temperature increases, the mechanical strength of materials decreases. While making such materials, there is a tendency to keep possibly low thermal weakening. In the course of operating gas turbines, various kinds of failures/defects/ damages may occur to components thereof, in particular, to blades. Predominating failures/damages are those attributable to the material overheating and thermal fatigue, all of them resulting in the loss of mechanical strength. The paper has been intended to present findings on changes in the microstructure of blades made of nickel-base alloy due to high temperature. The material gets overheated, which results in the deterioration of the microstructure’s condition. The material being in such condition presents low high-temperature creep resistance. Any component, within which such an effect occurs, is exposed to a failure/damage usually resulting in the malfunctioning of the turbine, and sometimes (as with aero-engines) in a fatal accident. Failures/damages of this kind always need major repairs, which are very expensive.


1967 ◽  
Vol 45 (3) ◽  
pp. 329-345 ◽  
Author(s):  
Peter H. Johansen

The heat resistance of normal, hypophysectomized and pituitary-autotransplanted goldfish acclimated to 20 °C under 16-h photoperiod and 8-h photoperiod conditions was determined. It was found that hypophysectomized goldfish were less heat resistant than normal fish and that those with an autotransplanted pituitary were as heat resistant as normal fish.The photoperiod results, though inconclusive, suggest that normal 16-h photoperiod fish are more heat resistant than normal 8-h photoperiod fish and that only the fish with a normal pituitary can respond to photoperiod changes. The fish without a pituitary are slightly less heat resistant than normal 8-h-photoperiod fish, while those possessing an autotransplanted pituitary are as resistant to a high temperature as normal 16-h-photo period fish.Treatment of hypophysectomized goldfish with luteinizing, thyrotropic, adrenocorticotropic, and lactotropic (prolactin) hormones and crude salmon pituitary extract appeared not to affect resistance to a high temperature.In the experiments involving pituitary autotransplantation, a study was made of various organs influenced by pituitary secretions to determine the pattern of hormone output by the pituitary. By contrasting this information with that of the heat resistance tests, various hormones have been suggested as not playing an essential role in high temperature resistance. The hypothesis is put forward that a prolactin-like hormone plays the essential role in resisting a high-temperature stress.


Author(s):  
E. N. Kablov ◽  
Yu. A. Bondarenko ◽  
M. Yu. Kolodyazhny ◽  
V. A. Surova ◽  
A. R. Narsky

The paper presents the scientific, technical and technological aspects in the field of creating new high-temperature materials for parts of the hot section of gas turbine engines (GTE) with operating temperatures exceeding those existing in GTE. More refractory metallic materials for the creation of new high-heat-resistant alloys used for the manufacture of rotor and nozzle blades and other parts of promising gas turbine engines based on NiAl-Ni3Al, Co-Cr-Re, Pt-Al, Nb-Si, Mo-Si-B systems have been investigated. It is shown that, depending on the composition of the selected matrix, the working temperature of heat-resistant alloys increases to 1300-1500°С, which is significantly higher than the existing nickel heat-resistant alloys.


2012 ◽  
Vol 78 (21) ◽  
pp. 7753-7759 ◽  
Author(s):  
William M. Smith ◽  
Thi Huong Pham ◽  
Lin Lei ◽  
Junchao Dou ◽  
Aijaz H. Soomro ◽  
...  

ABSTRACTDuring construction of several gene deletion mutants inLactococcus lactisMG1363 which involved a high-temperature (37.5°C) incubation step, additional spontaneous mutations were observed which resulted in stable heat resistance and in some cases salt-hypersensitive phenotypes. Whole-genome sequencing of one strain which was both heat resistant and salt hypersensitive, followed by PCR and sequencing of four other mutants which shared these phenotypes, revealed independent mutations inllmg_1816in all cases. This gene encodes a membrane-bound stress signaling protein of the GdpP family, members of which exhibit cyclic dimeric AMP (c-di-AMP)-specific phosphodiesterase activity. Mutations were predicted to lead to single amino acid substitutions or protein truncations. An independentllmg_1816mutant (Δ1816), created using a suicide vector, also displayed heat resistance and salt hypersensitivity phenotypes which could be restored to wild-type levels following plasmid excision.L. lactisΔ1816 also displayed improved growth in response to sublethal concentrations of penicillin G. High-temperature incubation of a wild-type industrialL. lactisstrain also resulted in spontaneous mutation ofllmg_1816and heat-resistant and salt-hypersensitive phenotypes, suggesting that this is not a strain-specific phenomenon and that it is independent of a plasmid integration event. Acidification of milk by thellmg_1816-altered strain was inhibited by lower salt concentrations than the parent strain. This study demonstrates that spontaneous mutations can occur during high-temperature growth ofL. lactisand that inactivation ofllmg_1816leads to temperature resistance and salt hypersensitivity.


2013 ◽  
Vol 20 (4) ◽  
pp. 331-335 ◽  
Author(s):  
Bin Zhao ◽  
Qilei Wang ◽  
Lin Jin

AbstractA ferric oxide (Fe2O3)/silicone rubber (SR) composite was prepared to produce a magnetic rubber with good heat-resistant and friction properties: SR and nano-Fe2O3 were used as its raw materials. The heat-resistant, antiflaming, magnetic, and mechanical properties of such composites with different proportions of nano-Fe2O3 were studied. The results showed that the Fe2O3 nanoparticles were uniformly distributed throughout the composites. The physical and mechanical properties of SR were improved when Fe2O3 nanoparticles were added. The maximum elongation and tensile strength of the composites were relatively good when the ratio of Fe2O3 was 20 phr. The heat-resistance and antiflaming properties of SR were improved by adding nano-Fe2O3, which had good combined heat resistance. The friction properties of these composites were optimal at 20 phr addition of nano-Fe2O3, which laid the foundation for further applications of this type of composite in high-temperature sealing and shock absorption environments.


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