摘要:

AbstractPolyetherimide (PEI) is one of the latest generic high‐performance engineering thermoplastics. PEI (developed by General Electric (USA) under the trade name ULTEM) is an amber and amorphous polymer with a heat distortion temperature between those of polyarylate resin and thermally stable crystalline polymers such as polyether‐ether ketone (PEEK) and polyamideimide (PAI). It has excellent thermal, mechanical and electrical properties along with easy processability. In the work reported here, a wear‐resistant formulated composite supplied by GEC (ULTEM 4001) was selected for tribological investigations on a pin on disc machine under unlubricated conditions, against mild steel. Analysis of the composite revealed that this grade contained PTFE (13–15%), which is the most promising polymeric lubricant.A very low and stable frictional coefficient was observed against moderately finished surfaces. However, its specific wear resistance (⋍10−14m3/Nm) was comparatively lower than that of fibre‐reinforced thermoplastics. The wear mechanism was found to be significantly dominated by the presence of PTFE. The friction coefficient was in the range of 0.2 and reduced to a still lower value (0.1) as the apparent contactpressure increased. Scanning electron microscopy was used to investigate the underlying wear mechanism. Film transfer of PTFE was observed to be the principal factor responsible for red

ISSN:0265-6582    

DOI:10.1002/jsl.3000060302

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe ‘Deuterium Isotope Effect’ was investigated as a means of further increasing the oxidation resistance of soap‐thickened greases utilized in miniature bearing applications. Using lithium stearate as a model compound, the bearing performance life and induction period for oxidation were determined on four different greases prepared from non‐deuterated and deuterated base oil and thickener. The expected increase in oxidation resistance and bearing performance life was observed for the deuterated base fluid; however, the use of a deuterated thickener did not provide any significant improvement. Details concerning the preparation of thickener and grease formulations and their properties are pr

ISSN:0265-6582    

DOI:10.1002/jsl.3000060303

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe physical and performance characteristics of representative synthetic base stocks are compared with those of mineral oils. Comparisons of the base stocks alone and as fully formulated crankcase lubricants are presented.Bench test results and physical properties of unformulated synthetic and mineral oil base stocks are compared. The volatility characteristics of synthetic base stocks are superior to typical mineral oil base stocks. All the synthetic base stocks displayed greater viscosity indices than did mineral oils. Bench tests designed to measure thermal and oxidative stabilities are used to compare synthetic with mineral oil base stocks. Although synthetics appeared no more resistant to oxidation than did mineral oils, fewer sediments, deposits and fluid viscosity increases were observed with synthetic base stocks. No one type of synthetic base oil showed a distinct advantage in these evaluations.Fully formulated mineral oil‐based lubricants are compared with commonly used synthetic‐based lubricants containing identical additive treatments. The synthetic lubricants showed superior engine cleanliness, and resistance to viscosity increased in these tests, but were directionally less effective in wear prevention than mineral oil‐based lubricants. Proper formulation or addition of an antiwear supplement overcame this deficiency.These comparisons demonstrated that synthetic base stocks are available with a wide range of physical properties. Available synthetic base stocks offer performance advantages at an increased cost over mineral oils, but proper formulation of the synthetic lubricant is necessary to ensure totally acceptable lubricant perfor

ISSN:0265-6582    

DOI:10.1002/jsl.3000060304

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThis paper explains the nature offire‐resistant, water‐based hydraulic fluids, and their applications, and gives comparisons with mineral oil‐based hydraulic fluids. The content of the different types of fluid is described, and the technical requirements for water‐based hydraulic fluids discussed. The chemistry of the synthetic thickeners of water, their thickening effect and shear stability, as well as their technical properties, are explained and compared. The construction and the mode of action of thickeners for hydraulic fire‐resistant fluids (HFAS) or viscous high‐water‐based fluids (VHWBF) are detailed, and the physical chemistry of these hydrophilic‐hydrophobic thickeners, which form microemulsions in water, is considered in interaction with emulsifying agents. In this case laser‐light scattering correlation spectroscopy is sh

ISSN:0265-6582    

DOI:10.1002/jsl.3000060305

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000060306

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000060307

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA detailed listing of future meetings of interest to the lubricants community. For further information, readers should apply to the address given. News on forthcoming lubricants conferences is welcome for inclusion in this section.

ISSN:0265-6582    

DOI:10.1002/jsl.3000060308

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractJSLincludes this section on the activities, products and services offered by its subscribers. This listing appears each issue, and is updated regularly, to help readers locate those companies of potential use to the synthetic lubricants community. To participate, fill in the form provided at the back of this issue, and send it to the publishers at the address given on the back of the form.

ISSN:0265-6582    

DOI:10.1002/jsl.3000060309

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0265-6582    

DOI:10.1002/jsl.3000060301

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY