Zobrazeno 1 - 10
of 29
pro vyhledávání: '"Larry S. Helmick"'
Publikováno v:
Tribology Letters. 7:17-25
In bench tribology tests, the influence of lubricant decomposition products on the lubricated system and on lubricant performance are often overlooked, primarily because testing is performed in vented, or open, systems. However, the lubricant in a ga
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c0b07b94bf3341e90e05317792029f9f
https://doi.org/10.1023/a:1019148731854
https://doi.org/10.1023/a:1019148731854
Autor:
Shashi K. Sharma, Larry S. Helmick
Publikováno v:
Tribology Letters. 6:123-127
Humidity is an uncontrolled variable in many tribology tests. This report shows that changes in relative humidity can affect wear for all perfluoropolyalkylethers regardless of their molecular structure. Using a Cameron–Plint tribometer under contr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3d0457fa1f6748b7311a8619cfc0d0fe
https://doi.org/10.1023/a:1019103521859
https://doi.org/10.1023/a:1019103521859
Autor:
Bruce Schreiber, Shashi K. Sharma, Carl E. Snyder, Lois J. Gschwender, George W. Fultz, Larry S. Helmick
Publikováno v:
Tribology Transactions. 41:78-86
In previous research, high wear of M-50 bearing steel in low humidity air environments was observed for RfO(CF2O)x (CF2CF2O)y(CF2CF2CF2O)zRf base fluid in a reciprocating tribometer. In this work, the effect of humidity on wear was observed with a fo
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7c35d2dd2c0c947d97db94c36f4c1aaf
https://doi.org/10.1080/10402009808983724
https://doi.org/10.1080/10402009808983724
Publikováno v:
Tribology Letters. 4:287-292
It has previously been shown using 19F nuclear magnetic resonance (NMR) spectroscopy that a linear perfluoropolyalkyl ether (PFPAE) fluid undergoes decomposition by a disproportionation reaction mechanism to form acid fluorides when heated in the pre
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::83289e92b241fcb8f9eb0f20e31bf6b1
https://doi.org/10.1023/a:1019144314165
https://doi.org/10.1023/a:1019144314165
Publikováno v:
Tribology Letters. 3:113-119
Tribology experiments under controlled humidity were conductedusing a Cameron-Plint tribometer with an M-50 cylinder slidingon an M-50 flat specimen in the presence of a linearperfluoropolyalkylether fluid. The tests were conducted at 100,70, 59, 10,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5c2dca8d08304ec1ca79ce14c237fe24
https://doi.org/10.1023/a:1019191913314
https://doi.org/10.1023/a:1019191913314
Autor:
Lois J. Gschwender, Larry S. Helmick, Jim C. Liang, George W. Fultz, Shashi K. Sharma, Carl E. Snyder
Publikováno v:
Tribology Transactions. 40:393-402
A reciprocating tribometer and four-ball tribometer were used under controlled environmental conditions to determine the wear behavior of bearing steels with a linear perfluoropolyalkylether (PFPAE) lubricant which does not contain difluoroacetal gro
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9b2cfaf3b808de178b3e30d6af57d6e0
https://doi.org/10.1080/10402009708983673
https://doi.org/10.1080/10402009708983673
Autor:
Larry S. Helmick, Jim C. Liang
Publikováno v:
Tribology Transactions. 39:705-709
The tribochemistry of a linear perfluoropolyalkylether (PFPAE) resulting from sliding friction experiments was investigated by FTIR spectroscopy. The experiments were conducted on a Cameron-Plint tribometer under boundary lubrication conditions in a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b78d227efc0a7e8e7b7843ba10cf61c5
https://doi.org/10.1080/10402009608983586
https://doi.org/10.1080/10402009608983586
Publikováno v:
Tribology Transactions. 38:571-576
Two commercial poly(hexafluoropropene oxide) fluids were thermally pretreated at 343 C in pure oxygen. IR and nuclear magnetic resonance(NMR) spectra indicate that this pretreatment was effective in removing hydrogen end-capped impurities. A decrease
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f1f85950a958132902e2991216fccea8
https://doi.org/10.1080/10402009508983444
https://doi.org/10.1080/10402009508983444
Publikováno v:
Journal of Synthetic Lubrication. 11:111-119
Tribological characteristics of three PFPE's (Fomblin Z, Demnum, and Krytox) were studied under high vacuum using a four-ball apparatus with 440C steel specimens. Fomblin Z and Demnum exhibited initial scuffing-like high friction whereas Krytox did n
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1a61ea51bd3057f0167e094e772fe7eb
https://doi.org/10.1002/jsl.3000110204
https://doi.org/10.1002/jsl.3000110204
Autor:
Larry S. Helmick, William R. Jones
Publikováno v:
Tribology Transactions. 33:519-528
A computerized tensimeter and experimental procedure for determination of the thermal decomposition temperature (T sub d) of perfluoro alkylethers were developed and tested. Both the apparatus and the procedure are described in detail. Results of tes
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::8da025b81cc5255fe63b0c2a4ce8c0ac
https://doi.org/10.1080/10402009008981984
https://doi.org/10.1080/10402009008981984