摘要:

AbstractThis paper reports on the method and preliminary results of a significant modification of the Noack volatility test. This modification permits collection and examination of the volatile products as well as of the residue. The analysis of such volatiles by chromatography and spectroscopy revealed surprising information that is especially relevant in the face of increasingly difficult automotive and heavy duty engine emission limitations. The data also showed very close agreement with the Unified Test Method for the Noack Volatility Test now covered by CEC L‐40‐T‐87. Important to operators, the authors' modified Noack apparatus avoids the use of the toxic Wood's Metal of the earlier Noack appa

ISSN:1354-4063    

DOI:10.1002/tt.3020010102

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractCircular point contact EHD pressure distributions were investigated under various operating conditions using a thin film piezo‐resistive pressure transducer. A series of controlled experiments, in which the active element of the transducer is positioned at various contact cross‐sections, was carried out. The results are analysed and presented in the form of isobars. The pressure distribution closely describes the Hertzian pressure profile with a secondary pressure peak appearing prior to and near the exit constrict

ISSN:1354-4063    

DOI:10.1002/tt.3020010103

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractFactors affecting the mechanical stability of polyalkylmethacrylate type additives are comparatively examined for different shear degradation test methods and routine engine service, taking into account rheological and size exclusion chromatography data. The shear test methods are assessed regarding the MWD of the degraded additives.The extent of degradation of macromolecular additives and the molecular weight distribution (MWD) of the degraded products depend on the nature and extent of shear stress, average molecular weight, MWD, chemical structure, nature of the base oil and temperature. The shape of the MWD of the sonicated and automotive service subject additives was found to be similar, unlike that of the additives sheared by the diesel injector method. These are narrower and more dependent on the initial MWD of the additive, especially in the case of the additives with broader MWD. A shear test that better correlates with service has to take into account not only the control of shear stress, by appropriate calibration, but also a suitable degradation mechanism.

ISSN:1354-4063    

DOI:10.1002/tt.3020010104

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020010105

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe tribology laboratories described here are part of the Bundesanstalt für Materialforschung und ‐prüfung (Federal Institute for Materials Research and Testing), known as

ISSN:1354-4063    

DOI:10.1002/tt.3020010106

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020010107

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020010108

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020010109

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020010101

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY