Experimental and Theoretical Studies of Distribution of Vacancy Clusters in Depth of Material Irradiated by High-Energy Particles

Non-destructive method of positron depth sensing of the radiation defects in solids was proposed and implemented. The depth distribution of vacancy clusters in molybdenum irradiated by protons with energy of 30 MeV was found based on the experimental data. Theoretical calculations of this value were made and sufficient agreement between calculations and experiment was obtained

Computer simulation radiation damages in condensed matters

As part of the cascade-probability method were calculated the energy spectra of primary knocked-out atoms and the concentration of radiation-induced defects in a number of metals irradiated by electrons. As follows from the formulas, the number of Frenkel pairs at a given depth depends on three variables having certain physical meaning: firstly, C[d] (E[a] h) is proportional to the average energy of the considered depth of the PKA (if it is higher, than the greater number of atoms it will displace); secondly is inversely proportional to the path length [lambda]2 for the formation of the PKA (if [lambda][1] is higher than is the smaller the probability of interaction) and thirdly is inversely proportional to E[d]. In this case calculations are in satisfactory agreement with the experimental data (for example, copper and aluminum)

Computer simulation and study of the IR spectra of irradiated polymer materials

Within the framework of MDDP the calculations of IR spectra have been performed for the initial polyethylene terephthalate (PET) and its state with the cation which satisfactorily describing experimental data. The calculations were made using the MDDP (modified neglect of diatomic differential overlap), implemented in the program MOPAC 2012. A feature of the method is that the overlap integrals are replaced by the [delta]-function, single-site Coulomb and exchange integrals are calculated by atomic parameters Slater-Condon. In recent years the studies of the structure and physico-chemical properties of polyethylene terephthalate and composites made on it basis have got the intensive development. Comparison of calculations with experimental data gives their satisfactory agreement

Catastrophic models of materials destruction

The effect of concentration and type of fillers on mechanical properties of composite material based on polyimide were studied. Polyethylene terephthalate (PET, polyester), polycarbonate (PCAR) and montmorillonite (MM) were used as the fillers. The samples were prepared by mechanically blending the polyimide-based lacquer solutions with different concentrations of the second component. The concentration of filler and its class, especially their internal structure and technology of synthesis determine features of physical and mechanical properties of obtained materials. Models of catastrophic failure of material satisfactorily describe the main features depending on tension ct from deformation e

Investigation of Mechanical Properties of Polyimide- Polyethyl-eneterephthalate System

The study of the physico-mechanical properties of new composite materials based on polyimide (PI) and polyethyleneterephthalate (PET) was carried out. Dependences of σ from ε for different concentrations of the second component and irradiation doses were measured. The experimental data are described satisfactorily by the exponential cascadeprobabilistic model

Development of technology and investigation of structure and properties of composites on the basis of shungit and polymer resins

The technology for manufacturing of composites based on polymer (epoxy) resins and shungites was developed by using of the electron irradiation and experienced samples with different percentages of the components a) 90 and 10 %, b) 70 and 30 %, c) 50 and 50 %, were manufactured respectively. It was carried out the series of experimental studies of the structure and properties of the obtained materials, including the atomic force microscope images were obtained and Raman spectra of these composites were measured and their analysis was per-formed

Effect of thermomechanical impacts on the deformation of thin polyimide films at uniaxial tension

Thermomechanical studies of the dependence of deformation on time (t) and temperature (T) for various static stresses in polyimide under uniaxial tension were carried out. Temporal deformation curves for static stresses in the range from 75 to 110 MPa consist of two stages: 1 - increase; 2 - exit to saturation, which is associated with a change in the nature of structural transformations of macromolecules, due to the action of the static stresses. An increase in temperature and voltage leads to an increase in the dependence e (Т). This is due to the intensification of the processes of structuring macromolecules with increasing temperature and are supplemented by processes of breaking bonds between macromolecules, which increase the strain rate. Experimental data are described in terms of exponential and linear models

Computer simulation and study of the IR spectra of irradiated polymer materials

Within the framework of MDDP the calculations of IR spectra have been performed for the initial polyethylene terephthalate (PET) and its state with the cation which satisfactorily describing experimental data. The calculations were made using the MDDP (modified neglect of diatomic differential overlap), implemented in the program MOPAC 2012. A feature of the method is that the overlap integrals are replaced by the [delta]-function, single-site Coulomb and exchange integrals are calculated by atomic parameters Slater-Condon. In recent years the studies of the structure and physico-chemical properties of polyethylene terephthalate and composites made on it basis have got the intensive development. Comparison of calculations with experimental data gives their satisfactory agreement

Study of the influence of the electron irradiation dose on the deformation of Mylar films taking into account the processes of destruction and crosslinking

Experimental studies of the dependence of the deformation [epsilon] on the dose of electron irradiation D taking into account the processes of destruction and crosslinking for films of the Mylar type have been carried out. It was obtained that the dependence of [epsilon] on D for the process of cross-linking is described by a linear and destruction by an exponential function

Study of the influence of the electron irradiation dose on the deformation of Mylar films taking into account the processes of destruction and crosslinking

Experimental studies of the dependence of the deformation [epsilon] on the dose of electron irradiation D taking into account the processes of destruction and crosslinking for films of the Mylar type have been carried out. It was obtained that the dependence of [epsilon] on D for the process of cross-linking is described by a linear and destruction by an exponential function