ISSN:0954-0075    

DOI:10.1002/ls.3010100302

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractThe effect of the molecular structure of basic nitrogen compounds on the lubricating properties of sulphurised olefin has been investigated using a Timken tester. X‐ray Photoelectron Spectroscopy (XPS) and Energy Dispersive X‐ray Analysis (EDAX) were used to study the chemical states of sulphur and nitrogen on the rubbed surfaces and the reaction rates of sulphur and iron separately. It was found that the antiwear and friction reduction properties of sulphurised olefin are greatly influenced by the different molecular structures of the basic nitrogen compounds. A composite additive package containing basic nitrogen compounds with sulphurised olefin can produce either synergistic or antagonistic effects, due to the influence of the different molecular structures of the basic nitrogen compounds. XPS analysis revealed that a tribochemical protective film containing nitrogen and sulphur was formed on the rubbed surface. EDAX analysis indicated that the reaction rates between elemental sulphur and iron were influenced by the different molecular structures of the basic nitrogen compounds. It was found that the apparent reaction rates of elemental sulphur and iron are related to the tribological characteristics of the additive pack

ISSN:0954-0075    

DOI:10.1002/ls.3010100303

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractThis paper reviews the chemistry, mechanisms, and interactions of antiwear and extreme‐pressure additives used to supplement the performance of lubricants. Some examples with respect to their application are also give

ISSN:0954-0075    

DOI:10.1002/ls.3010100304

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractThe synthesis of four oil‐soluble rare earth complexes of diethylammonium lanthanide tetrakis(diethyldithiocarbamate) (ReDTC) is described. The tribological properties of these rare earth complexes as additives in lubricating oil have been evaluated using a four‐ball machine. The results show that these novel complexes have excellent extreme‐pressure properties and selective antiwear properties in lubricating oil. The action mechanism of the rare earth complexes as additives in lubricating oil was investigated using X‐ray photoelectron spectroscop

ISSN:0954-0075    

DOI:10.1002/ls.3010100305

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractThe influence of temperature on the rheological characteristics of lubricants has been investigated by analysing the viscosity‐temperature relationship and energy equation of lubricants. The constitutive equation, which describes the non‐Newtonian properties of lubricants caused by thermal effects, is founded and coupled with equations of continuity and momentum of the fluid to calculate the load‐carrying capacity in hydrodynamic lubrication. The numerical solutions show that lubricants have ultimate shear strength as a result of the non‐Newtonian effect of temperature, which leads to the oil film having limiting load‐carrying capacity. The mechanism of film failure in hydro‐dynamic lubrication is also studied preliminarily in

ISSN:0954-0075    

DOI:10.1002/ls.3010100306

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractFriction and wear tests of Si3N4against cast iron were carried out using a ring‐on‐block tester lubricated by emulsion. To provide a comparison with emulsion, distilled water was also used as a lubricant in the tests. The results show that emulsion can prevent the formation of an SiO2·2H2O film on the iron surface. Although the friction coefficient of Si3N4/ iron pairs in emulsion is much greater than in distilled water, the wear of Si3N4in emulsion is

ISSN:0954-0075    

DOI:10.1002/ls.3010100307

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractViscosity modifiers are one of the most important components of multi‐viscosity grade lubricants. In use, the lubricant heats up and the ingredients degrade and deplete. In an attempt to understand the thermal and thermal‐oxidative behaviour of viscosity modifiers, we have studied the effects of heat in both inert and oxidative atmospheres. The paper describes the degradation of a styrene‐isoprene viscosity modifier studied with differential scanning calorimetry (DSC). Most of the kinetic parameters can be obtained by the application of Kissinger, Ozawa, and Augis and Bennett's simple expressions, which are special cases of Elder's formulations. The values of order, heat of degradation, and activation energy were +1.25, +1149 J·m, and 175 kJ·mole for thermal degradation in a nitrogen atmosphere, and +1.50, −6321 J·m, and 57 kJ·m for thermal‐oxidative degradation in air. The information concerning the degradation of the viscosity modifying polymers can be useful in selecting the correct polymers for envisage

ISSN:0954-0075    

DOI:10.1002/ls.3010100308

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

ISSN:0954-0075    

DOI:10.1002/ls.3010100301

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY