Structural and phase transformations in titanium alloyed with chromium and molybdenum atoms under the action of compression plasma flows

Abstract

The change in structure and phase composition of the surface layer of titanium alloyed with chromium and molybdenum atoms under the action of compression plasma flows with an absorbed energy density of 13–35 J/cm2 is studied. It is established that the alloyed layer with a thickness of up to 27 μm contains α-Ti, α′-Ti, and β-Ti phases whose volume fraction is determined by the concentration of alloying element and parameters of processing. The formation of titanium nitrides is observed in the surface layer. The growth of absorbed energy density results in the reduction of the concentration of alloying element and reduction of the volume fraction of nitrides and β-Ti. The processing by compression plasma flows makes it possible to increase the microhardness of the surface layer by a factor of 2.5 and reduce the friction coefficient by a factor of 4.6.