Plasticity mechanics
In this research line there are two work directions:
- Mathematical modeling of the plastic deformation processes and interpretation of the mechanical behavior of the mechanic-rheological properties of materials in different structure states and under different exploitation conditions.
- Development and examination of the technological capabilities of new methods for cold volumetric deformation – discrete extrusion, non-mandrel pressing, elastoplastic treatment.
These methods are characterized by the achievement of ultrahigh degrees of deformation and by the possibility to elaborate highly effective technologies for producing longitudinal cavity profiles and products made of multicomponent materials with different physical-mechanical properties.
Statistical theory of plasticity is developed and on its basis a number of theoretical and theoretical-experimental algorithms are suggested as well as unique experimental plants for determination of the material mechanical behavior in a wide range of operational conditions. For these conditions respective strength criteria are formulated and experimentally proved and mechanic-mathematical models are developed that reflect the rheological properties of the deformed media. Mathematical models are suggested which describe the mechanical behavior of the metals for a wide variety of structure states (obtained as a result of plastic treatment in the range from conventional to ultrahigh degrees of deformation and after subsequent heat treatments in different conditions).
There are developed and investigated the technological possibilities of new methods for cold volumetric deformation (elastoplastic treatment, discrete extrusion, non-mandrel pressing), characterized by the capability to achieve ultrahigh degrees of plastic deformation. The theoretical bases of these methods are elaborated and in connection with their realization unique specialized machines, devices and tool equipment are designed. Technologies are developed for production of longitudinal cavity profiles and for composite materials and products representing structural material complexes which contain both solid and fluid components.
Innovation technologies are elaborated for production of contact nozzles for electric arc welding of ferrous and non ferrous metals by electrode wire, in protective gas medium (MIG-TIG) and submerged arc welding.
The nozzles are manufactured by modern technology, with invariable diameter of the welding wire opening along all the length and they guarantee stable welding conditions and high quality of the weld seam. The technology guarantees high hardness, wear resistance and long life of the nozzles at low process.
The contact nozzles can be made with no limitation concerning configurations and dimensions which provides possibility to meet the customer requirements independently of the type of the welding equipment that is available.
Together with the conventional designs of welding contact nozzle there is also offered a patent defended innovation solution providing better characteristics than the currently existing world standard – contact nozzle with triangular cross section of the inside opening.
Plastic deformation
In the field of the technological bases of the plastic deformation there are investigated the effects of the deformation parameters on the structure formation and the improvement of the metal materials properties. The investigations on the behavior of volumetric construction metal materials under intensive plastic deformations (multistage extrusion) with the purpose to produce sub-microcrystalline and nano-materials are at initial step.
- Methods are developed for using the parameters of similarity to solve problems in plastic deformation of metal materials with application in the rolling processes.
- Results are obtained for the plastic behavior of new and conventional materials in conditions of hot and semi-hot plastic deformation.
- On the basis of large-scale investigations a wide range of results are obtained for the plastic behavior of new low alloyed high strength microalloyed steels of grades 10Г2САФ, 17Г2САФ and 23Г2САФ, of new nitrogen stainless, high speed and die steels, providing possibility to design and model the plastic deformation processes.
- The plastic deformation processes are examined in deep drawing of thin sheet materials with pressing, combined deep drawing with thinning as well as multipass drawing. New data are obtained about the effect of the plastic deformation parameters on the structure formation and the properties of some ferrous and non ferrous metals – ship steels, new lead alloys, aluminum alloys.
- Investigations are performed and results obtained for the effect of different degrees of deformation on the deformability and properties of casting aluminum alloy А356 in rolling.
- Investigations are performed and results obtained for the effect of the technological parameters of the liquid metal crystallization, rolling in the billet mill and all stages of seamless steel pipes production on the quality and causes for defects of the pipes. Two supplements in the standard ГСТУ 3-0009-2000 are suggested.
- Multistage deformation technology is developed for compaction of nanostructure alloys from initial powder and tape materials as well as for production of microcrystalline structure composite alloys. The technology is applied for production of ingots and parts with real dimensions of high strength А1-Fе-V-Si alloys intended mainly for machine building as replacement for some titanium alloys in the aircraft construction operating both at normal and higher temperatures. The product presented is made of aluminum alloy of microcrystalline structure characterized by absolute structure homogeneity (therefore the mechanical properties) along all axes. In theoretical aspect a system of criteria is developed which permit to define the type of the deformation processes going during high temperature deformation of nanostructure alloys. This will assist the selection of optimum temperature-rate and deformation conditions for plastic treatment of this type of materials.
