Structural Changes and Diffusion in the Zone of Contact Deformation of Copper Alloys Under Friction.

Calculation of diagrams of components of residual stress tensor arising in the surface layer of a tribomaterial under sliding friction is used to formulate ideas about the role of the medium in creating a plasticizing and strengthening triboeffect. The characteristics of the structural state of the surface layers of brasses, aluminum and tin bronzes during their friction against steel in surface-active lubricants are presented. The conditions for achieving minimum power losses to friction and wear are determined. The role of local diffusion phenomena in quasi-spinodal phase transitions observed in surface micro-volumes of copper alloys during their contact deformation is revealed. It is shown that among industrial copper alloys, brass of the L90 type, aluminum bronzes BrA5, BrA7, and tin bronzes BrOF4-0.25, BrOF6,5-0,15 have the greatest wear resistance in surface-active lubricants. Examples of implementation of the phenomenon of selective transfer in friction pairs are given. Recommendations are developed for its use in friction units of machines and devices. [ABSTRACT FROM AUTHOR]