Influence of Thermal Treatment on the Structure, Physical and Mechanical Properties of Nanostructured Coatings (Ti, Hf, Nb, Si)N Deposited by C-PVD Method

The paper describes the nanostructured coatings produced by C-PVD method at various deposition conditions. Samples with thickness of 2, 3 mm and diameter 10, 42 mm were constructed of steel 0.55 % Fe, 0.45 % C with polished surface. The samples were tested by XRD (small angle X-Ray diffraction), SEM with EDX, AFM, scratch – tester REVETEST, tests of wear resistance and acoustic emission, nanoindenter before annealing. It was discovered that the size of nanograins varied from 3,3 nm to 8 nm by annealing at 500°, 800° and 1000°C. By dint of μ- PIXE were discovered the segregation process of impurities at the junctions of interfaces and at nanograin boundaries. Moreover as a result of the thermal annealing hardness of coatings increased on 18- 20 %. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3523

Preparation, Structural and Optical Characterization of ZnO/Ag Thin Film by CVD

Zinc Oxide thin films doped with Ag have been synthesized by CVD technique. By increasing the dopant from 0 to 10 % Ag in ZnO thin films were found to lead to pronounced changes in their morphology. From optical properties the band gap energy of pure ZnO thin film was 3.25 eV, with the increasing of Ag doping from 1 to 10% it is not affected. X-ray diffraction has shown that the maximum intensity peak corresponds to the (101) predominant orientation for ZnO and ZnO:Ag. SEM images show that more crystalline behavior by increasing the doping. EDXA analysis showed that the structure of ZnO film contains Zn and O elements and Ag, Cu, Si for doping at 10 % Ag

Analysis of the Influence of Deposition Conditions on the Structure of the Coating Nb-Al-N

Nanocomposite Nb-Al-N films prepared by magnetron sputtering have been studied. It has been found that, in the films, there are two stable crystalline structural states, namely, NbNz and B1-Nb1 – xAlxNyO1 – y, and an amorphous like component related to aluminum oxynitride upon reactive magnetron sputtering. The substructure characteristics are sensitive to the current supplied to an Al target and related to the Knoop nanohardness and hardness, which change within in the ranges of 29-33.5 and 46-48 GPa, respectively. Ab initio calculations for the NbNz and Nb2AlN phases and NbN / AlN heterostructures have been performed to interpret the obtained results for the first time

Structure and Properties NbN and Nb-Si-N Deposited by Magnetron Sputtering

NbN and Nb-Si-N films were deposited by magnetron sputtering the Nb and Si targets on silicon wafers at various bias voltage, Us. The films were investigated by an atomic force microscope (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nanoindentation. The deposited films were annealed to establish their thermal stability. The NbN films were nanostructured, and the Nb-Si-N films had a nanocomposite structure, and represented an aggregation of δ-NbNx nanocrystallites embedded into the amorphous Si3N4 tissue (nc-δ-NbNx/a-Si3N4)

Multilayer and high-entropy alloy-based protective coatings for solving the issue of critical raw materials in the aerospace industry

Aerospace is an actively developing industry that continuously requires the implementation of modern technologies. The rapid growth in new vehicle production demands much support. Hence, the problem of resources with complicated supply and distribution is always of current interest. These critical raw materials (CRMs) are involved in almost all areas of aerospace manufacturing and service. An efficient and profitable solution to the problem of critical materials can be found in protective coatings, especially in such advanced concepts as multilayer and high-entropy alloy (HEA)-based coatings. In this paper, we study both ways of manufacturing effective coatings. We have shown that multilayer CrN/MoN coatings with exceptional toughness and hardness could find promising applications in the aerospace industry. The developed strategy for the novel materials screening based on the prediction of their properties has been demonstrated on the example of the refractory HEA-based coatings. A brief state of the art of the EU critical raw materials and their place in the aerospace/defence industry has been given.The study has been partially supported and funded by the Ukrainian state budget via the project “Improved Physical and Mechanical Properties of Multilayer Protective Coatings Based on High Entropy Alloy Nitrides” (project № 0120U100475

Systematic review and meta-analysis of randomized clinical trials comparing efficacy and safety outcomes of insulin glargine with NPH insulin, premixed insulin preparations or with insulin detemir in type 2 diabetes mellitus

AIMS: A variety of basal insulin preparations are used to treat patients with type 2 diabetes mellitus (T2DM). We aimed to summarize scientific evidence on relative efficacy and safety of insulin glargine (IGlar) and other insulins in T2DM. METHODS: A systematic review was carried out in major medical databases up to December 2012. Relevant studies compared efficacy and safety of IGlar, added to oral drugs (OAD) or/and in combination with bolus insulin, with protamine insulin (NPH) or premixed insulin (MIX) in the same regimen, as well as with insulin detemir (IDet), in T2DM. Target HbA1c level without hypoglycemic events was considered the primary endpoint. RESULTS: Twenty eight RCTs involving 12,669 T2DM patients followed for 12–52 weeks were included in quantitative analysis. IGlar + OAD use was associated with higher probability of reaching target HbA1c level without hypoglycemia as compared to NPH + OAD (RR = 1.32 [1.09, 1.59]) or MIX without OAD (RR = 1.61 [1.22, 2.13]) and similar effect as IDet + OAD (RR = 1.07 [0.87, 1.33]) and MIX + OAD (RR = 1.09 [0.86, 1.38]). IGlar + OAD demonstrated significantly lower risk of symptomatic hypoglycemia as compared to NPH + OAD (RR = 0.89 [0.83, 0.96]), MIX + OAD (RR = 0.75 [0.68, 0.83]) and MIX without OAD(RR = 0.75 [0.68, 0.83]), but not with IDet + OAD (RR = 0.99 [0.90, 1.08]). In basal-bolus regimens, IGlar demonstrated similar proportion of T2DM patients achieving target HbA1c as compared to NPH (RR = 1.14 [0.91, 1.44]) but higher than MIX (RR = 1.26 [1.12, 1.42) or IDet (RR = 1.38 [1.11, 1.72]). The risk of severe hypoglycemia was lower in IGlar than in NPH (RR = 0.77 [0.63, 0.94]), with no differences in comparison with MIX (RR = 0.74 [0.46, 1.20]) and IDet (RR = 1.10 [0.54, 2.25]). IGlar + OAD has comparable safety profile to NPH, with less frequent adverse events leading to treatment discontinuation than MIX + OAD (RR = 0.41 [0.22, 0.76]) and IDet + OAD (RR = 0.40 [0.24, 0.69]). Also severe adverse reactions were less common for IGlar + OAD when compared to MIX + OAD (RR = 0.71 [0.52; 0.98]). CONCLUSION: For the majority of examined efficacy and safety outcomes, IGlar use in T2DM patients was superior or non-inferior to the alternative insulin treatment options. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00592-014-0698-4) contains supplementary material, which is available to authorized users

The effect of Al target current on the structure and properties of (Nb2Al)N films with an amorphous AlN phase

Nanocomposite films based on (Nb2Al)N intermetallic nitride have been obtained by the method of magnetron sputtering. Xray diffraction analysis revealed two stable states of the crystalline structure: (i) NbN with low amount (within 5 at %) of dissolved Al in a composition close to (Nb2Al)N and (ii) an amor phous component related to aluminum nitride formed by reactive magnetron sputtering. The substructural characteristics (grain size and microdeformation level) are sensitive to the current via Al target and exhibit correlation with nanohardness and Knoop hardness of the film, which vary within 29–33.5 and 46–48 GPa, respectively

Structure and properties of nanostructured NbN and Nb-Si-N films depending on the conditions of deposition: Experiment and theory

The first results of studying the phase–structural state, properties, sizes of nanograins, hardness, and microstresses in nanocomposite NbN and Nb–Si–N films are given. The investigated films were obtained by the method of the magnetron sputtering of Nb and Si targets onto silicon substrates at different negative potentials at the substrate (from 0 to –70 V), nitrogen pressures PN, and discharge powers at the targets. To determine the thermal stability of the films, they were annealed at 600, 800, and 1000°C in a vacuum.It was revealed for the first time that the NbN films have a twophase nanocomposite structure, which consists of δNbN (NaCl structure type) and α'NbN. The δNbN phase is also formed in Nb–Si–N films, where it is enveloped by an amorphous Si3N4 phase The hardness of the Nb–Si–N films reaches 46 GPa, which cor responds to the level of superhardness, while the hardness of the NbN nanocomposites is somewhat lower, but also very high (34 GPa). The experimental results for the Nb–Si–N films were explained based on the data obtained from the firstprinciples calculations of the NbN/SixNy heterostructures by the molecular dynamics method