Rubber: Butyl (IIR Abbreviation), Phosphate Ester Resistant, 65 to 75 Hardness, for Seals in Hydraulic Systems, etc.

2019 ◽  
Author(s):  
2019 ◽  
Author(s):  
James Ewen ◽  
Carlos Ayestaran Latorre ◽  
Arash Khajeh ◽  
Joshua Moore ◽  
Joseph Remias ◽  
...  

<p>Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. To rationally design phosphate esters with improved tribological performance, an atomic-level understanding of their film formation mechanisms is required. One important aspect is the thermal decomposition of phosphate esters on steel surfaces, since this initiates film formation. In this study, ReaxFF molecular dynamics simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. On Fe<sub>3</sub>O<sub>4</sub>(001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature is increased from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>, most of the molecules are physisorbed, even at high temperature. Thermal decomposition rates were much higher on Fe<sub>3</sub>O<sub>4</sub>(001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately film formation. On Fe<sub>3</sub>O<sub>4</sub>(001), thermal decomposition proceeds mainly through C-O cleavage (to form surface alkyl and aryl groups) and C-H cleavage (to form surface hydroxyls). The onset temperature for C-O cleavage on Fe<sub>3</sub>O<sub>4</sub>(001) increases in the order: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is in agreement with experimental observations for the thermal stability of antiwear additives with similar substituents. The results highlight surface and substituent effects on the thermal decomposition of phosphate esters which should be helpful for the design of new molecules with improved performance.</p>


Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  

Abstract Haynes Ti-3Al-2.5V alloy is used where the strength/weight ratio is of prime importance; the alloy is 43% lighter than 21-6-9 stainless steel. It is most often used in the form of seamless tubing for aircraft hydraulic systems. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on forming, heat treating, and joining. Filing Code: TI-145. Producer or source: Haynes International Inc.


Alloy Digest ◽  
2014 ◽  
Vol 63 (2) ◽  

Abstract Mecasteel 145 (minimum yield strength 145 ksi) is a high-strength prehardened steel that can be used in substitution for conventional steels, such as AISI 4330, in the manufacture of massive steel components such as machines, hydraulic systems, and pumps. This datasheet provides information on composition and tensile properties as well as fracture toughness. It also includes information on forming. Filing Code: SA-691. Producer or source: Industeel USA, LLC. Revised as Alloy Digest SA-703, July 2014.


Alloy Digest ◽  
2014 ◽  
Vol 63 (3) ◽  

Abstract Mecasteel 90 (minimum yield strength 90 ksi) is a high-strength prehardened steel that can be used in substitution for conventional steels, such as AISI 4130, in the manufacture of massive steel components such as machines, hydraulic systems, and pumps. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on forming and joining. Filing Code: SA-697. Producer or source: Industeel USA, LLC.


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