LAUSR

We study the tribological properties of materials used as electrocontact inserts of the tram pantographs in couples with M1copper of the contact wires of power electric circuits. As promising materials for the pantograph insert, we considered the composites based on the MAX phases of Ti3AlC2, (Ti, Nb)3AlC2, and Ti2AlC and also on TiC and Al2O3. The highest wear resistance was detected for composites with a content of the MAX phase of structural modification 312 equal to 85–95%. The wear of these materials after 5 km of their operation under a contact stress of 0.25 MPa (which corresponds to the operating conditions) turns out to be 20 times lower than for the aluminum alloy used in the Ukraine for the production of pantograph inserts. The wear resistance of M1 copper also depends on the phase constitution of the material of inserts: in couples with composites based on 95% Ti3AlC2 + 5% TiC or 85% (Ti, Nb)3AlC2 + 10% TiC + 5% Al2O3, it was 4–5 times higher than in contact with aluminum alloy.