In forming processes contact friction significantly influence metal flow, stress-strain state and process parameters. Furthermore, tribological conditions influence workpiece surface quality and its dimensional precision. This paper presents research results of the influence of contact friction coefficient on a workpiece surface quality in ring upsetting by flat plates. Workpiece surface roughn...

Lubricating greases are colloid disperse systems consisting of a base oil and a thickener (additional additives). The lubricant is modeled as a tribological system, and the reaction of a fluid friction stress is investigated. The energetic situation of the volume element is analyzed and the system entropy described. The description of the structural degradation and the used entropy was realized...

Current theories assume that the amphiphilicity of biological membranes is always preserved. We observed that two hydrogen-bonding lipid layers in contact can spontaneously and reversibly lose their amphiphilic structure and turn into an assembly of oily complexes. This result opens a new angle for understanding the reorganization of lipids during membrane fusion, since similar complexes could ...

in the past 30 years, electroless nickel (en) plating has grown to such proportions that these coatingsand their applications are now found underground, in outer space, and in a myriad of areas inbetween. moreover, in order to further improve the mechanical and tribological properties of thenickel-phosphorous (ni-p) coatings, ni-p/ptfe composite coatings can be obtained, which provideseven grea...

A series of sebacic acid esters containing mercaptobenzothiazole and dialkylenedithiocarbamate, which are potential environmentally friendly lubricating grease additives, were synthesized. The tribological properties as lubricating additives in Li-soap greases were evaluated using a 4-ball tester and SRV tester. The results show that the series of sebasic acid esters with dioctyldithiocarbamate...

Literature review indicates that a large amount of failures are caused by abnormal wear of the diesel engine components. It is therefore essential to monitor the engine condition using the tribological information. Although the wear debris analysis has been proven to be effective for condition monitoring and fault diagnosis (CMFD) of diesel engines, limited work has been done to address the rem...