Tribological Properties of Coatings Obtained with Electrocontact Welding of Metal Powder Materials

The investigations of tribo mechanical properties of coatings obtained with electrocontact welding of sintered powder materials and powder-polymer fillers of Russian manufacture are presented. It is proved that the introduction of antifriction components (powders of copper or tin) into filler material at a rate of 5-10 % increases the time to joints seizure by 1.5-2 and decreases by 1.5 the friction ratio. The application of powder-polymer and sintered fillers reinforced with metal grid produces a relief on the operating surface of the coating with the areas possessing minimum hardness. They are worn out more intensely and the forming herewith grooves help to keep lubricating oil on the friction surface. For the friction pair operating in abrasive wear conditions with adhesive wear elements, at welding it is recommended to use powder compositions (by weight): 80-90 % – PG-FBX6-2, 10-20 % of copper powder friction ratio (PMS-N); for wear conditions at adhesive wear: 90 % of iron powder (PZHR 3.200.28), 10 % of tin powder (PO-1); for abrasive wear conditions: 70-80 % – PG-FBX6-2, 30-20 % – VK8.