lprocesses during friction of copper powder, which is the basis of many antifriction materials, on ceramic coatings applied to steel. The coating's base consisted of oxides (Table I) possessing a high resistance to wear and to corrosion. The coatings were applied by plasma spraying (plasma-forming gas -- argon) on to steel 07KhI6N6 (HRC = 36-38). To increase the bonding strength of the coating with the base, and reduce the chances of cracking during friction heating, a sublayer of powdered nichrome PKh20N80 [7] was first sprayed on to the steel. The ceramic coating 300 ~m thick was ground with diamond wheels using lubricant-coolin g to i00 ~m. The roughness and microhardness data are shown in Table I. Specimens were pressed from PMS-I copper powder and sintered in hydrogen at 820~ for 1 h. To reduce the blank's porosity they were pressed again and repeatedly sintered at 900~ for 1 h. The porosity was 7.4-7.9%. Friction and wear tests were made on a rig designed by the Institute of Physics Problems, Academy of Sciences of the Ukrainian SSR [9] in face-friction Conditions using three specimens and a disc with a coefficient of mutual overlap of 0.15, and a load of 0.i MPa. Specimens were cylindrical, height and diameter 15 mm. The sliding rate was altered in stages from ii to 22 and 40 m/sec, and the tests were continued for 1800, 600, and 180 sec respectively. The linear wear and frictional force were recorded. The average temperature of the friction surface was measured with a chromel-copper thermocouple placed at about 0.5 mm from it. Before the tests the surfaces of the specimen and coatings were carefully degreased with ethyl alcohol. A complex method was used to study the physicochemical processes of friction; this included the scanning electron microscope, Auger-spectroscopy*, x-ray structural analysis, and reflexion electrography#. The Auger spectra were obtained on the JAMP-10S spectrometer with a probe diameter of 5 and i00 pan. In the Auger spectrometer column the friction surface was etched by a mean of argon ions, removing a layer of material at a rate of about 2 nm/min. The electronographic studies were made on the I~-i00 instrument with an accelerating voltage of i00 kV. The phase composition of the friction surface was studied on the DRON-2 diffractometer in Cu-K~-radiation. The diffraction lines for copper were recorded as points, and the expansion was determined by approximation. The standard consisted of copper obtained by sintering PMS-I powder in hydrogen at 900~ for 2 h. To compare the levels of the residual elastic stresses we investigated cast copper grade MoB after rolling on rollers 180 mm in diameter, with compressions during one pass of 10-15% (total compression 40%). With a sliding rate of ii m/sec the relationships between the friction coefficient and test time, for all pairs, are complicated. They can tentatively be divided into three parts: on the first (less than I0 min) the friction coefficient has a low value (0.13-0.25); on