Accession Number : AD0903246

Title :   The Effect of Iodine on the EHD Film and Traction Properties of Hexadecane in Rolling Contact.

Descriptive Note : Final rept.,

Corporate Author : SKF INDUSTRIES INC KING OF PRUSSIA PA RESEARCH LAB

Personal Author(s) : Chiu, Y. P.

Report Date : 20 JUN 1972

Pagination or Media Count : 20

Abstract : Film thickness was observed optically and traction was recorded for the rolling/sliding contact of a 1/2 in. diameter 52100 steel ball of 64 Rc hardness and a glass flat using both pure hexadecane fluid and hexadecane with the addition of 0.00750% iodine by weight at ambient temperature of the order of 76F. The objectives were to determine whether iodine caused (1) a lessening of the maximum traction coefficient in rolling/sliding contact and (2) an associated change in EHD Film forming ability and/or film shape. Color photographs were obtained under loads of 5 and 10 lbs, per ball corresponding to 100,000 to 126,000 PSI maximum Hertz pressure at rolling speeds ranging from 20 to 400 in/sec. Maximum traction coefficient was measured with pure hexadecane and the same fluid with 0.5% and 0.0075% iodine at loads of 5 and 10 lbs. and rolling velocities of 40 and 100 in/sec. Sliding velocity was varied from zero to 20 in sec in these tests to assure that the maximum traction was achieved as a function of sliding speed. A stained track roughly 0.020 in. in width developed on the glass flat when using the iodine solution. Anomalies in the shape of the EHD contacts characterized by lack of roundness and of a horseshoe shaped constriction were noted and are ascribed to this deposit. Sliding tests with 75 ppm iodine solution resulted in a wear track 0.015 in. wide 30 mu-in. deep on the glass flat. Measured traction was somewhat higher with the iodine solution, however audible scratching sounds indicating that glass-metal contact was taking place, make it doubtful that fluid traction alone was being measured.

Descriptors :   *HYDROCARBONS), (*LUBRICANT ADDITIVES, IODINE), (*IODINE, BALL BEARINGS, LUBRICATION, LUBRICANTS, ELASTIC PROPERTIES, FLUID DYNAMICS, HYDRODYNAMICS, FRICTION, SKIN FRICTION, ADDITIVES, FILMS, ROLL, THICKNESS, SLIDING CONTACTS, ELECTROSTATICS, SOLUTIONS(MIXTURES), GLASS, METALS, WEAR RESISTANCE.

Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Lubricants and Hydraulic Fluids

Distribution Statement : APPROVED FOR PUBLIC RELEASE