Accession Number : AD0479698


Title :   FRICTION AND WEAR BEHAVIOR OF SOLID FILMS


Descriptive Note : Annual rept. 31 Dec 1964-31 Dec 1965


Corporate Author : MRIGLOBAL KANSAS CITY MO


Personal Author(s) : Bryant, Paul J ; Gutshall, Paul L


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/479698.pdf


Report Date : Feb 1966


Pagination or Media Count : 33


Abstract : A new friction and wear system is described. The coefficient of friction and the wear rate of a single crystal or a compressed pellet sample may be measured in the same atmosphere as cleavage energy or stress-relaxation experiments are being conducted. This combined ability in one system gives a true basis for correlating data from fundamental measurements and actual frictional tests. The simultaneous experiments may be performed in ultra-high vacuum, or various controlled atmospheres. Sets of data are reported for the friction and wear of graphite in two forms: pyrolytic graphite, and compressed graphite pellets. The two sample forms differ in both the size and relative orientation of their graphite lamellae. Data are compared for both sample forms in six environments: air, vacuum, oxygen, water, methanol and carbon tetrachloride. The effect of each environment was more pronounced on crystalline graphite samples than on pellet samples. The most notable difference is the low wear rate which has been measured for pyrolytic samples in ultra-high vacuum. This absence of 'dusting wear' accompanied by a moderate coefficient of friction for unannealed pyrolytic graphite is very interesting in regard to many possible applications. An optical microscope study of the surfaces resulting from bulk shear of graphite crystals is presented. The majority of new area produced apparently results from unresolved lamellar shear. However, some of the applied shear stress appears to be resolved in cleavage and also dissipated into deformation of the sample. Similar experiments with molybdenite yield a truer shearing action; comparisons are described.


Descriptors :   *GRAPHITE , *LUBRICANTS , *WEAR RESISTANCE , AIR , CARBINOLS , CARBON TETRACHLORIDE , CRYSTAL LATTICES , CRYSTALS , ENVIRONMENTAL TESTS , FRICTION , GRAIN STRUCTURES(METALLURGY) , MICROSCOPY , MOLYBDENUM COMPOUNDS , OXYGEN , SHEAR STRESSES , SINGLE CRYSTALS , SOLIDS , SULFITES , VACUUM , VISUAL INSPECTION , WATER


Subject Categories : Lubricants and Hydraulic Fluids


Distribution Statement : APPROVED FOR PUBLIC RELEASE