FORMATION OF WEAR-RESISTANT SURFACE STRUCTURES AND THEIR DAMAGE MECHANUSM IN FRICTION WITH LUBRICANT MODIFIED BY ULTRADISPERSED DIAMOND-GRAPHITE ADDTITIVES (PART 2: DAMAGE MODEL)

摘要

A physical model of the damage of friction member materials lubricated with oil modified by ultradispersed diamond-graphite additives is proposed on the basis of linear failure mechanics. It has been shown in the first part of the study that the modification of lubricant with ultradispersed diamond-graphite additives (UDDG) accelerates essentially the running-in of friction pairs under light contact pressures. Under heavy contact pressures (P{sub}a = 20-30 MPa) the efficiency of lubricant modification with UDDG additives depends on the initial hardnesses of the mated materials. In friction of hardened steel 45 against hardened steel UDDG additives intensify damage processes at microlevel and accelerate transition to severe wear. In view of this it is of interest to interpret the experimental data obtained in [1] in terms of linear failure mechanics.