Influence of surface machining operations on mechanical properties of chromium-nickel steels at low temperatures

1974 ◽  
Vol 6 (4) ◽  
pp. 436-443 ◽  
Author(s):  
N. V. Novikov ◽  
N. I. Gorodyskii ◽  
E. �. Zasimchuk ◽  
O. D. Maidich
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
Surface Machining ◽  
Machining Operations

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
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