An Evaluation of the Effect of Low Temperatures on Mechanical Properties of a Commercial Steel to be Used in the Arctic

1980 ◽  
Vol 8 (1) ◽  
pp. 42 ◽  
Author(s):  
KC Lieb ◽  
RT Horstman ◽  
B Power ◽  
RL Meltzer ◽  
MB Vieth ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
The Arctic ◽  
Commercial Steel

Static and Cyclic Behavior of Welded DH36 Steel and Its Application at Low Temperatures

2021 ◽  
pp. 1-31
Author(s):  
Weidong Zhao ◽  
Guoqing Feng ◽  
Bernt J. Leira ◽  
Huilong Ren
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
Fatigue Tests ◽  
Cyclic Behavior ◽  
Brittle Transition ◽  
Ductile To Brittle Transition

Abstract The mechanical properties of welded DH36 steel at low temperatures are important to the safety of structures in Polar areas. The purpose of the study is to investigate the static and cyclic behavior of welded DH36 steel at low temperatures based on tensile and fatigue tests. The Ductile to Brittle transition and Fatigue Ductile to Brittle Transition of welded DH36 steel occurred at low temperatures. Finally, some relevant applications of the results within the context of polar engineering and design are discussed in the last part of the present study.

scholarly journals Effect of TiO2 Nanoparticles on Physical and Mechanical Properties of Cement at Low Temperatures

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Li Wang ◽  
Hongliang Zhang ◽  
Yang Gao
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
Cement Hydration ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
Cementitious Materials ◽  
Strength Test ◽  
Hydration Degree ◽  
Time Test

Low temperature negatively affects the engineering performance of cementitious materials and hinders the construction productivity. Previous studies have already demonstrated that TiO2 nanoparticles can accelerate cement hydration and enhance the strength development of cementitious materials at room temperature. However, the performance of cementitious materials containing TiO2 nanoparticles at low temperatures is still unknown. In this study, specimens were prepared through the replacement of cement with 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.%, and 5 wt.% TiO2 nanoparticles and cured under temperatures of 0°C, 5°C, 10°C, and 20°C for specific ages. Physical and mechanical properties of the specimens were evaluated through the setting time test, compressive strength test, flexural strength test, hydration degree test, mercury intrusion porosimetry (MIP), X-ray diffraction (XRD) analysis, thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM) in order to examine the performance of cementitious materials with and without TiO2 nanoparticles at various curing temperatures. It was found that low temperature delayed the process of cement hydration while TiO2 nanoparticles had a positive effect on accelerating the cement hydration and reducing the setting time in terms of the results of the setting time test, hydration degree test, and strength test, and the specimen with the addition of 2 wt.% TiO2 nanoparticles showed the superior performance. Refined pore structure in the MIP tests, more mass loss of CH in TGA, intense peak appearance associated with the hydration products in XRD analysis, and denser microstructure in SEM demonstrated that the specimen with 2 wt.% TiO2 nanoparticles exhibited preferable physical and mechanical properties compared with that without TiO2 nanoparticles under various curing temperatures.

scholarly journals Modyfikowanie HTPB (α,ω-dihydroksypolibutadienu) w reakcjach estryfikacji, silanizacji, epoksydacji i uwodornienia

2018 ◽  
pp. 30-45
Author(s):  
Michał Chmielarek ◽  
Paweł Maksimowski ◽  
Tomasz Gołofit ◽  
Katarzyna Cieślak ◽  
Wojciech Pawłowski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
Frost Resistance ◽  
High Energy ◽  
Insulating Materials ◽  
Rocket Propulsion ◽  
Materials Research ◽  
Selection Of

HTPB is a valuable comonomer for the preparation of polyurethanes. Thanks to its specific properties, it gives these materials frost resistance and excellent mechanical properties, especially at low temperatures. The polyurethanes thus obtained are used in the production of propellants used in space and military rocket propulsion, and are the basis for frost-resistant adhesives and insulating materials. Research on the selection of binder indicates the use of high energy polymers or modifications of previously used polymers improving their properties. The results of research on ways of changing the properties of HTPB through its modification and thus an increase of application possibilities will be presented.

scholarly journals Efecto del dióxido de titanio en las propiedades mecánicas y autolimpiantes del mortero

2021 ◽  
Vol 25 (109) ◽  
pp. 88-97
Author(s):  
Carlos Magno Chavarry Vallejos ◽  
Liliana Janet Chavarría Reyes ◽  
Xavier Antonio Laos Laura ◽  
Andrés Avelino Valencia Gutiérrez ◽  
Enriqueta Pereyra Salardi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tio2 Nanoparticles ◽  
Low Temperatures ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Cementitious Composites ◽  
Palabras Clave ◽  
Self Cleaning

El presente artículo tiene como objetivo determinar la influencia de la adición del dióxido de titanio (TiO2) en el mortero de cemento Pórtland Tipo I. La investigación es descriptiva, correlacional, explicativo, con diseño experimental, longitudinal, prospectivo y estudio de cohorte. Se elaboró una mezcla patrón y tres mezclas de mortero con 5%, 7.5% y 10% de contenido de TiO2 como reemplazo del volumen de cemento para las propiedades autolimpiantes se realizó el ensayo de rodamina e intemperismo. La incorporación de dióxido de titanio disminuyó la resistencia a la compresión, incrementó la fluidez y tasa de absorción de agua; la prueba de rodamina dio que el mortero sin actividad fotocatalítico no contenía TiO2 porque no cumple con los factores de fotodegradación R4 y R26. Mediante la exposición de paneles al intemperismo favoreciendo la propiedad autolimpiante de los morteros con adición de TiO2 (5%). Palabras Clave: Actividad foto catalítico, dióxido de titanio, factores de fotodegradación, propiedades mecánicas y autolimpiante. Referencias [1]E. Medina and H. Pérez, “Influencia del fotocatalizador dióxido de titanio en las propiedades autolimpiables y mecánicas del mortero de cemento - arena 1:4 - Cajamarca,” Universidad Nacional de Cajamarca, 2017. [2]G. Abella, “Mejora de las propiedades de materiales a base de cemento que contienen TiO 2 : propiedades autolimpiantes,” Universidad Politécnica de Madrid, 2015. [3]J. Gonzalez, “El Dióxido de titanio como material fotocatalitico y su influencia en la resistencia a la compresión en Morteros,” Universidad de San Buenaaventura Seccional Bello, 2015. [4]D. Jimenez and J. Moreno, “Efecto del reemplazo de cemento portland por el dioido de titanio en las propiedades mecanicas del mortero,” Pontificia Universidad Javeriana, 2016. [5]L. Wang, H. Zhang, and Y. Gao, “Effect of TiO2 nanoparticles on physical and mechanical properties of cement at low temperatures,” Adv. Mater. Sci. Eng., 2018, doi: 10.1155/2018/8934689. [6]Comisión de Normalización y de Fiscalización de Barreras Comerciales no Arancelares, Norma Técnica Peruana. Perú, 2013, p. 29. [7]ASTM Internacional, “ASTM C150,” 2021. https://www.astm.org/Database.Cart/Historical/C150-07-SP.htm. [8]M. Issa, “( current astm c150 / aashto m85 ) with limestone and process addition ( ASTM C465 / AASHTO M327 ) on the performance of concrete for pavement and Prepared By,” 2014. [9]S. Zailan, N. Mahmed, M. Abdullah, A. Sandu, and N. Shahedan, “Review on characterization and mechanical performance of self-cleaning concrete,” MATEC Web Conf., vol. 97, pp. 1–7, 2017, doi: 10.1051/matecconf/20179701022. [10]C. Chavarry, L. Chavarría, A. Valencia, E. Pereyra, J. Arieta, and C. Rengifo, “Hormigón reforzado con vidrio molido para controlar grietas y fisuras por contracción plástica,” Pro Sci., vol. 4, no. 31, pp. 31–41, 2020, doi: 10.29018/issn.2588-1000vol4iss31.2020pp31-41. [11]D. Tobaldi, “Materiali ceramici per edilizia con funzionalità fotocatalitica,” Università di Bologna, 2009. [12]Norme UNI, “Norma Italiana UNI 11259,” 2016. http://store.uni.com/catalogo/uni-11259-2008?josso_back_to=http://store.uni.com/josso-security-check.php&josso_cmd=login_optional&josso_partnerapp_host=store.uni.com. [13]E. Grebenisan, H. Szilagyi, A. Hegyi, C. Mircea, and C. Baera, “Directory lines regarding the desing and production of self-cleaning cementitious composites,” Sect. Green Build. Technol. Mater., vol. 19, no. 6, 2019. [14]M. Kaszynska, “The influence of TIO2 nanoparticles on the properties of self-cleaning cement mortar,” Int. Multidiscip. Sci. GeoConference SGEM, pp. 333–341, 2018.

Mechanical properties of oxidized titanium alloys at low temperatures

1970 ◽  
Vol 12 (6) ◽  
pp. 471-473
Author(s):  
S. I. Gudkov ◽  
D. V. Lebedev ◽  
V. V. Reznichenko
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
Low Temperatures

Fluorine-Containing Elastomers

1961 ◽  
Vol 34 (5) ◽  
pp. 1521-1552 ◽  
Author(s):  
J. C. Montermoso
Keyword(s):  
World War Ii ◽  
Air Force ◽  
Department Of Defense ◽  
Low Temperatures ◽  
Task Force ◽  
The Arctic ◽  
World War ◽  
Arctic Regions ◽  
Rubber Compounds ◽  
Fuel Leakage

Abstract Fluoroprene, the first fluorine-containing elastomer, was developed by E. I. du Pont de Nemours … Company and reported by Mochel and others in 1948. However, intensive research to develop specialty rubbers from fluorocarbons was not started until the early 1950's. At the time, there was an urgent military need for fuel and chemical resistant rubbers for service under extremely low temperatures. Consequently, most of the fluorine-containing elastomers were the result of research conducted or sponsored by the Department of Defense. Army experiences in the Aleutians during World War II and in several task force operations in the Arctic regions showed, among others, that fuel hoses became brittle and cracked. Gaskets failed to function. On shipboard, the Navy was experiencing similar difficulties with rubber items. The Air Force, on the other hand, was being plagued with an epidemic of fuel leakage on many of its aircraft. The extraction of the plasticizers from the nitrile rubber compounds and the low temperature of the environment caused shrinkage of the seals and gaskets resulting in leakage of fuels. Obviously, a solution to these problems was to develop new fuel resistant rubbers which would be inherently flexible at extremely low temperatures.

The effect of plasticization on the properties of poly(urethaneureas) based on oligoether diols, 2,4-toluenediisocyanate, and aromatic diamines

2018 ◽  
Vol 51 (4) ◽  
pp. 337-358 ◽  
Author(s):  
Vasiliy Tereshatov ◽  
Marina Makarova ◽  
Valeriy Senichev ◽  
Zhanna Vnutskikh ◽  
Tamara Oshchepkova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Arctic Climate ◽  
The Arctic ◽  
Aromatic Diamines ◽  
Plasticization Effect ◽  
Soft Segments ◽  
Potential Applications ◽  
Partial Crystallization ◽  
First Time

Segmented poly(urethaneureas) (SPUUs) modified with low glass transition temperature chemically inert liquids are of interest due to their controllable properties and potential applications under various environmental conditions. Investigation into the influence of plasticizers on the properties of SPUUs based on oligotetramethyleneoxide diol (polytetramethyleneoxide), oligopropyleneoxide diol (polypropyleneoxide), 2,4-toluenediisocyanate, Ethacure-300, and methylene-bis- o-chloroaniline was conducted. Partial crystallization of polytetramethyleneoxide segments was identified during cooling of some SPUU samples plasticized by di-(2-ethylhexyl)sebacate (DEHS) and tributyl phosphate. Polypropyleneoxide segments did not crystallize under the same conditions. A low crystallization temperature for the amorphous component of the polymer matrix in SPUU (−100°C to 103°C) was attained at a molecular mass ( Mn) of soft segments equal to 2000 g mol−1 and a DEHS concentration equal to 40–45%. A relationship between the mechanical properties of plasticized SPUU, microphase segregation, and dilution of the polymer matrix was found. For the first time, the effect of dilution with plasticizer on the strength of elastomers was considered. The plasticization effect on the mechanical properties of SPUU was investigated in the temperature diapason from 50°C to −70°C. The results of these investigations can be used in various technologies including the design of SPUUs with high elastic properties at temperatures as low as −70°C, typical of extreme conditions of the Arctic climate.

Sign in / Sign up

Export Citation Format

Share Document