Accession Number : AD0704043

Title :   METHOD FOR DETERMINING THE CRITICAL TEMPERATURE OF APPEARANCE OF A BOUNDARY LUBRICATING FILM,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Klimov,K. I. ; Kichkin,G. I.

Report Date : 21 JAN 1970

Pagination or Media Count : 12

Abstract : A new method for determining critical temperature (disorientation) of a boundary lubricant film is described. It is based on a method the reverse of that used previously, which starts from friction with a complete film, followed by transition to friction with a totally destroyed film. In the present method, friction at an unlubricated interface changes to surface friction. The four-ball friction machine designed by V. P. Paylov is used in the experiments. The friction coefficient is recorded by a photo-registering camera. The run is started with thoroughly rinsed, dry balls, followed by gradual lubrication. Graphic representation shows a sharp drop in friction coefficient at the point of boundary lubricant film formation. This drop becomes less sharp with rising test temperature and no jump is observed in the curve when the critical temperature is reached. The critical temperature for hydrocarbon lubricants is directly proportional to molecular weight and test product viscosity. An equation gives the relationship between average molecular weight and critical temperature. Prior methods give false results because the deteriorated lubricant film represents a different chemical composition than the starting material due to breakdown and oxidation. (Author)

Descriptors :   (*LUBRICATION, TRANSITION TEMPERATURE), BOUNDARY LAYER, OILS, FRICTION, FILMS, USSR

Subject Categories : Lubricants and Hydraulic Fluids

Distribution Statement : APPROVED FOR PUBLIC RELEASE