Papers by Author: Oleg Girin

Abstract: The further evidence is presented for the phenomenon existence of the electrochemical phase formation of metals and alloys through the stage of the overcooled liquid state. An idea is proposed about the possible occurrence of wave-like shapes on the surface of metal deposits, electrodepositing under weak force impact. First it was predicted and then revealed experimentally, a wave-like vibration of a solidifying surface of the metal being electrodeposited in the form of ripples or choppiness under the weak force impact in parallel to the crystallization front. A mathematical model has been obtained describing the liquid state behaviour of metals being electrodeposited under the impact of centrifugal force on the annular plate. The generalized Maxwell model was used as the basic rheological equation of a state. The difference between the results obtained is testified when considering Newtonian and non-Newtonian (power-law) liquid. The software blocks for solving the obtained mathematical model, based on the MathCAD package, have been developed.

Abstract: On the basis of the discovered phenomenon of phase and structure formation of metallic materials being electrodeposited through a stage of liquid state it was predicted and experimentally proved the following: a) formation of intermediate phases in the form of intermetallides in electrodeposited metallic alloys during the electrochemical crystallization of a liquid phase of two metals of different valences; b) formation of intermediate phases with complex crystal lattices in the form of carbides during solidification of a liquid phase of a transition metal alloyed with carbon; and c) formation of eutectics in electrodeposited metallic alloys as a result of decomposition of a liquid phase into two separate solid phases during its solidification. Intermetallides Cu5Zn8 and Cu6Sn5 in electrodeposited alloys of Cu-Zn and Cu-Sn systems, carbides Fe3C and Cr3C2 in electrodeposited iron and chromium alloyed with carbon, and eutectics in electrodeposited alloys of Sn-Zn and Pb-Cu systems were found.

Abstract: It has been found that during the electrodeposition of metallic material a supercooled metallic liquid is being formed that is solidified at the deposition temperature in the form of a crystalline or amorphous phase. These phase transformations are proved by the existence in the electrodeposited metals of metastable structures that correspond to: the amorphous structure of the solidified metallic liquid, the highly defective crystalline structure of the metal quenched from the liquid state, and the intermediate modifications that had appeared during the fast crystallization of the liquid phase of the polymorphous metal. On the basis of this phenomenon there have been developed the technologies for producing of protective texturally-composite tin electrocoat, nanostructurally-texturally-composite chromium electrocoat, and amorphous composite chromium electrocoat on canned-food steel sheet.