Investigation of element profiles, defects, зhase composition and physical and mechanical properties of superhard coatings Ti-Hf-Si-N

This paper investigates the microstructure, physical, chemical and mechanical of superhard nanocomposite of Ti-Hf-Si-N. The coatings were grown by C-PVD method. Profiles of elements and vacancy-type defects (S-parameter measurements of the Doppler broadening of the annihilation peak DBAP) in the studied coatings were investigated. Defined and calculated the elastic modulus E, hardness H, friction, adhesion. Wear rate was determined as a function of the bias potential supplied to the substrate and the pressure in the chamber. The developed coatings have hardness of 37.8 to 48 GPa, the friction coefficient of 0.48 to 0.15, the grain size of the solid solution from 3.9 to 10.8 nm (depending on deposition conditions). It was found that positrons are trapped by defects at the junction of three or more nanograins interfaces. In some cases, there was formed two phases in coatings: a solid solution (Ti, Hf)N with different volume content of Hf in a solid solution, and an amorphous phase α-Si3N4 (the layer between the nanograins). When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3395

Structure and Properties of Nanostructured (Ti-Hf-Zr-V-Nb)N Coatings

Nanostructured coatings of (Ti-Zr-Hf-V-Nb)N were obtained by the Cathodic Arc Vapor Deposition (CAVD) method. To investigate these coatings, a number of complementary methods of elemental and structural analysis were used, namely, slow positron beam (SPB), proton microbeam (PIXE),micro- and nanoelectron beam(EDS and SEManalyses), and X-ray difraction method (XRD), including method of ““alpha-sin2ψ” measurement of a stress-strain state (X-ray strain measurement). Additionally, the texture of coatings before and ater annealing up to 873K (for time of annealing �= 30min) was also investigated. It was shown that increasing of stress-strain state in the coating during deposition increases the resistance to oxidation at high temperatures of annealing. It was also found that the redistribution of elements and defects, as well as their alignment (segregation), appeared due to thermally stimulated difusion. It is also connected with the process of spinodal segregation near grain boundaries and interfaces around the grains and subgrains. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3393

Дослідження впливу на мікроструктуру нанокомпозитного AlN-TiB[2]-TiSi[2] високотемпературного відпалу та імплантації

Розвиток сучасної промисловості та аерокосмічної галузі потребує створення нових та удосконалення вже існуючих матеріалів, що дозволяють реалізовувати процеси різання та обробки при високих температурах, швидкостях та великих питомих навантаженнях. Ці задачі можна вирішити методом утворення поверхневих структур з детермінованими властивостями

Simulation study of effects, operating temperature and layer thickness on thin film cigs solar cell performance

SCAPS- program is designed basically for the simulation and studying the properties of photonic devices. We explored the important controllable design parameters affecting the performance of the hetero junction solar cells, as operating temperature that we noticed increasing in J-V characteristics by increasing T. The effect of thickness of each layer on the performance of the cell was studied, an increasing of J-V characteristics with increasing p-layer. In the numerical example, 3 m absorber layer and CdS layer 0.05 m, ZnO layer 0.1 m, works the best for given doping density, if we change the optimum value, the efficiency can reach to 17.72 % with FF 83.88 %, Voc 0.725 Volt, Jsc 29.07 mA/cm2 at 300 K, in this case, we have come out the optimum parameters to achieve the best performance of this type of cell, and then to made comparison with practical CIGS cell. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2305

Radiation Resistance of high-entropy nanostructured (Ti, Hf, Zr, V, Nb)N coatings

The influence of high-fluence ion irradiation of nanostructured (Ti, Hf, Zr, V, Nb)N coatings is revealed for the first time. The energy of irradiating helium ions is equal to 500 keV, and their fluence falls into the interval 5 × 1016–3 × 1017 ions/cm2 . The performance of the coatings in a nuclear reactor is simulated by conducting post-irradiation thermal annealing at 773 K for 15 min. The elemental composition, structure, morphology, and strength properties of the (Ti, Hf, Zr, V, Nb)N coatings are studied before and after irradiation. No considerable structural and phase modifications in the coatings are found after irradiation, except for the fact that crystallites in the coatings drastically reduce in size to less than 10 nm. Nor does the atomic composition of the coatings change. It is shown that the microhardness of the coatings depends on the fluence of irradiating ions nonlinearly. It can be argued that the (Ti, Hf, Zr, V, Nb)N coatings are radiationresistant and hence promising for claddings of fuel elements in nuclear reactors

Radiation Resistance of high-entropy nanostructured (Ti, Hf, Zr, V, Nb)N coatings

The influence of high-fluence ion irradiation of nanostructured (Ti, Hf, Zr, V, Nb)N coatings is revealed for the first time. The energy of irradiating helium ions is equal to 500 keV, and their fluence falls into the interval 5 × 1016–3 × 1017 ions/cm2 . The performance of the coatings in a nuclear reactor is simulated by conducting post-irradiation thermal annealing at 773 K for 15 min. The elemental composition, structure, morphology, and strength properties of the (Ti, Hf, Zr, V, Nb)N coatings are studied before and after irradiation. No considerable structural and phase modifications in the coatings are found after irradiation, except for the fact that crystallites in the coatings drastically reduce in size to less than 10 nm. Nor does the atomic composition of the coatings change. It is shown that the microhardness of the coatings depends on the fluence of irradiating ions nonlinearly. It can be argued that the (Ti, Hf, Zr, V, Nb)N coatings are radiationresistant and hence promising for claddings of fuel elements in nuclear reactors

First-Principles Quantum Molecular Dynamics Study of TixZr1-xN(111)/SiNy Heterosrtructures

Heterostructures with 1 monolayer of Si3N4-like Si2N3 interfacial layer between five monolayers thick B1-TixZr1-xN(111), x 1.0, 0.6, 0.4 and 0.0, slabs were investigated by means of first-principles quantum molecular dynamics and structure optimization procedure using the Quantum ESPRESSO code. Slabs consisting of stoichiometric TiN and ZrN and random, as well as segregated B1-TixZr1-xN(111) solutions were considered. The calculations of the B1-TixZr1-xN solid solutions as well as of the heterostructures showed that the pseudo-binary TiN-ZrN system exhibits a miscibility gap. The segregated heterostructures in which the Zr atoms surround the SiyNz interface were found to be most stable. For the Zr-rich heterostructures, the total energy of the random solid solution was lower compared to that of the segregated one, whereas for the Ti-rich heterostructures the opposite tendency was observed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3518

Protection of specimens against friction and wear using titanium-based multicomponent nanocomposite coatings: A review

A review of the experimental results of studying multicomponent nanocomposite protective coatings of various chemical compositions (TiAlCrYN, TiAlSiBN, TiAlSiCuN, CrTiAlSiN, and TiHfSiN/NbN/Al2O3) developed in recent years is presented. An analysis of the available data on the chemical composition, hardness, oxidation resistance, thermal stability, friction, wear, adhesion strength, and corrosion properties of nanocomposite coatings with high physicomechanical characteristics is carried out. The application of the nanocomposite coatings in industry is exemplified using the performance characteristics of drills made from a high speed steel covered with a multicomponent protective coating

The Effect of γ-irradiation on the Structural and Physical Properties of CdSe Thin Films

Thin film of CdSe has been deposited on to clean glass substrate by using CBD technique at room temperature. The samples are irradiated by γ-ray with various doses (25,50,100,150) rad. These films are characterized by XRD, which indicated that as-deposited CdSe layers and irradiated films at 25 & 50 rad of γ- ray grew in cubic phase having preferred orientation along (111) plane in c-direction. Further the irradiated films at 100 & 150 rad of γ- ray show polycrystalline in nature and with a mixture of cubic along with hexagonal structures. Optical absorption spectra of these thin films have been recorded using spectrophotometer. The energy band gap has been determined using these spectra. It is found that energy band gap of CdSe film is 2.09 eV and it is increased as increasing γ- ray irradiation does. The electrical conductivity measurements gave a decrease in conductivity with the increase of γ- irradiation does. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3531