Influence of Active Elements of a Machining Medium on Electronic Structure and the Mechanism of Deformation of Surface Layers of Metal at Friction
V. V. Tykhonovych, V. M. Uvarov
G.V. Kurdyumov Institute for Metal Physics, NAS of Ukraine, 36 Academician Vernadsky Blvd., UA-03142 Kyiv, Ukraine
Received: 12.01.2011. Download: PDF
The article presents the results of complex studies of changes in local chemical composition and structural—phase transformations within the areas of contact interaction of steels in sliding in different environments. As shown, the deformation of the metal surface layers during a friction in air leads to saturation of the boundary areas of structural fragments with the carbon atoms, which are in octahedrical interstices of b.c.c. The carbon atoms form strong covalent bonds with the surrounding metal atoms and reduce the mobility of atoms at the boundaries. This one contributes to deformation hardening of surface layers of metal rubbing in the air and prevents its stratification under the surface friction. Plastic deformation of the surface layers of metal during a friction within the water leads to saturation of the boundary areas of structural fragments with oxygen atoms, which form the metastable atomic Fe—O—C clusters. These clusters and metal atoms of the crystal lattice separate regions with low electron density, which are the result of limited participation of valence electrons in the formation of covalent bonds between the metal atoms and the atoms of clusters. Aggregation of atomic Fe—O—C clusters at the boundaries of structural fragments leads to their displacement of one with respect to another at the low transverse shift stresses and contributes to the transition of a metal of the interacting asperities into the new structurally unstable state, in which it is involved in the hydrodynamic flow without the loss of continuity. This one leads to the formation of nanostructured wear-resistant layers on the surfaces of friction of bodies in water.
Keywords: plastic deformation, distribution of impurity atoms, electron structure, atomic clusters, friction.
PACS: 62.20.Qp, 62.25.-g, 68.37.Lp, 73.20.-r, 81.07.Bc, 81.16.Rf, 81.40.Pq
Citation: V. V. Tykhonovych and V. M. Uvarov, Influence of Active Elements of a Machining Medium on Electronic Structure and the Mechanism of Deformation of Surface Layers of Metal at Friction, Usp. Fiz. Met., 12, No. 2: 209—239 (2011) (in Russian), doi: 10.15407/ufm.12.02.209