Rheology of Multigrade Engine Lubricants in High Deformation Rate Extensional Flow

2003 ◽  
Author(s):  
S. Cordy ◽  
M. S. Barrow ◽  
S. W. J. Brown ◽  
K. Hawkins ◽  
P. R. Williams
2012 ◽  
Vol 60 (3) ◽  
pp. 31101 ◽  
Author(s):  
Weifeng Jiang ◽  
Xinglong Gong ◽  
Yulei Xu ◽  
Shouhu Xuan ◽  
Wanquan Jiang ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Zhi-chao Li ◽  
Ning Dang ◽  
Zhen-li Mi

The influence of hot deformation temperature on microstructure and texture of CGO silicon steel under the condition of a high deformation rate (100 s-1) was studied by SEM and EBSD techniques. The results indicate that the typical microstructures at room temperature consist of ferrite and pearlite under different hot deformation temperatures. The higher deformation temperature is beneficial to obtain a more uniform recrystallization microstructure and lower pearlite content. Cubic texture{100}001and rotated cubic texture{100}011are dominant texture components in the tested steels, and{111}112texture inγfiber is also strong, the intensity of which is higher than that of{111}110texture. Goss texture{110}001is weak. With the rising of the hot deformation temperature,{100}011texture decreases firstly and then increases at 1100°C. When the hot deformation temperature raises from 800°C to 900°C,{111}112texture shows an increasing trend, while{111}110texture content is stable. When the temperature further increases to 1100°C and 1150°C,{111}112and{111}110textures are slightly weakened.


2004 ◽  
Vol 126 (2) ◽  
pp. 162-169 ◽  
Author(s):  
M. S. Barrow ◽  
S. W. J. Brown ◽  
S. Cordy ◽  
P. R. Williams ◽  
R. L. Williams

We report a study of liquid jets formed by the collapse of bubbles under cavitation-generated pressure waves. Such jets involve an extensional flow which is characterized by high rates of extension, the latter being relevant to considerations of the flow of oils within dynamically loaded journal bearings. The technique reported here is found to be sensitive to the influence of extremely small concentrations of high molecular weight polymeric additive (xanthan gum). Commercial multigrade oils are also found to exhibit significantly larger resistance to extensional flow than their Newtonian counterparts and, insofar as the multigrade oils studied here are made viscoelastic by polymer additives, and possess significant levels of resistance to extension, the results provide evidence in support of a mitigating effect of viscoelasticity on cavitation, as mooted by Berker et al. [3].


2004 ◽  
Vol 5 (4) ◽  
pp. 349-364 ◽  
Author(s):  
M S Barrow ◽  
S W J Brown ◽  
S Cordy ◽  
P R Williams ◽  
R L Williams

2019 ◽  
Vol 32 ◽  
pp. 100550 ◽  
Author(s):  
Sergiy Kalnaus ◽  
Hsin Wang ◽  
Thomas R. Watkins ◽  
Srdjan Simunovic ◽  
Abhijit Sengupta

2011 ◽  
Vol 1295 ◽  
Author(s):  
Andreas Stark ◽  
Daniel Gosslar ◽  
Nikolai Pashkov

ABSTRACTIn the present study the α2 and the γ texture in a Ti-45Al (at.%) alloy were analyzed by means of x-ray diffraction after hot deformation. The initial Ti-45Al powder compact exhibits a random texture and shows a relatively high amount of α2 phase (about 34 vol.%). Various hot compression tests were performed at temperatures ranging from 700 °C to 1100 °C with strain rates of 5·10–4 s–1 and 5·10–2 s–1 up to a true deformation of ε = –1.Depending on the deformation temperature the γ-TiAl deformation texture consists of pure deformation components (700 °C) or components completely related to dynamic recrystallization (1100 °C). In contrast to the γ phase the α2 phase shows no remarkable changing of the deformation texture with increasing temperature. The α2 deformation texture basically consists of a similar component as it is known from hexagonal α-Ti, namely a tilted basal fiber. However, a significant influence of the deformation rate on the α2 texture formation is observed at temperatures above 800 °C. With increasing deformation temperature the α2 texture strengthens by applying a high deformation rate, whereas it weakens for a low deformation rate. This contrary behavior is attributed to the interaction of the α2 and γ phases during texture formation.


Author(s):  
P. Rhodri Williams ◽  
Matthew S. Barrow ◽  
Stephen Cordy ◽  
Karl Hawkins

We report experimental work involving the rapid uniaxial elongation of jets of mobile (i.e. low shear viscosity) liquids formed by the collapse of a gas bubble under a cavitation-generated shockwave. The results of this work establish that the jets experience a significant degree of extensional deformation, at high rates of extension (typically > 1000 s−1) which are relevant to considerations of journal bearing lubrication. The results of experiments conducted on samples of commercial multigrade motor lubricants in the 15W40 category indicate a substantially increased resistance to extensional flow when compared with the behaviour of their Newtonian counterparts. Interestingly, the technique is able to distinguish between the rheological properties of lubricants of identical category (15W40) which are formulated for use in different engines (petrol engine and diesel engine, respectively). The lubricant formulated for the latter application is found to exhibit the highest resistance to extensional flow.


2008 ◽  
Vol 483-484 ◽  
pp. 242-244
Author(s):  
M.N. Machmud ◽  
D. Mochizuki ◽  
M. Omiya ◽  
H. Inoue ◽  
K. Kishimoto

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