On the ability of polymers to self-lubrication in metal – polymer friction pairs

Results of comparative research of wear resistance of polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), ultrahigh molecular weight polyethylene (UHMWPE) and polyamide 6 (PA6) in friction pairs with 18Kh2N4МА, 08Kh18N10Т and 40Kh13 are presented. Self-lubricating ability of polymers was determined by the contact pressure value corresponding to the upper border of the diapason, in which the effect of stabilization of linear wear intensity values and by the length of this diapason along the axis of loads is shown. Carbon steel 45 was used as a base steel in the comparison. PEEK, UHMWPE and PA6 friction pairs show higher values of intensity of linear wear but decrease in ability to self-lubrication. However in friction pair PTFE – steel 18Kh2N4МА with the prevailing content of nickel (about 4%), expansion of a range of stabilization of linear wear intensity is observed. In friction pairs PTFE with steel 40Kh13, containing a considerable percentage of chrome (13%), in absence of nickel, and with steel 18Kh2N4МА containing a complex of nickel and chrome (10% and 18%, respectively), the least wear resistance and ability to self-lubrication of polymer are marked. Temperatures on polymer tribocontact corresponding to ranges of wear stabilization loadings in researched friction pairs are determined.