Effect of the Structural State and Oxide Coating on the Mechanostability of VT1-0 Titanium upon Its Cyclic Loading

Physics of the Solid State - The fatigue properties of a submicrocrystalline titanium are shown to be substantially higher than those of a coarse-grained state. A deposition of an oxide coating...     

Influence of barocryodeformation conditions on the properties of VT1-0 titanium alloy

The hydrogen content, mechanical characteristics, and acoustic emission parameters of VT1-0 commercial titanium alloy subjected to barocryodeformation are measured at 300 and 77 K and at 77 K with counterpressure. A correlation between the acoustic parameters and the hydrogen content is found under all barocryodeformation conditions.     

Dielectric Losses in Hydrogen-Saturated VT1-0 Titanium Induced by Eddy Current Propagation

Technical Physics - Dielectric loss tangent tanδ in hydrogen-saturated VT1-0 titanium has been studied in the hydrogen concentration range 190–2000 ppm and eddy current frequency...     

Strain-Induced Surface Roughening in Polycrystalline VT1-0 Titanium Specimens under Uniaxial Tension

Surface roughening in uniaxially tensile specimens of commercially pure titanium VT1-0 has been investigated using electron backscatter diffraction, optical and atomic force microscopy, and numerical simulation. It is shown that intragranular slip leads to the rotation of surface grains, due to which the grain surface is inclined and a terrace is formed at the interface with neighboring grains. The effect of the crystallographic grain orientation on the grain shape change and the degree of grain rotation occurring under constrained plastic deformation is demonstrated.     

Hydrogen accumulation and distribution during the saturation of a VT1-0 titanium alloy by an electrolytic method and from a gas atmosphere

The accumulation, distribution, and thermally stimulated release of hydrogen in a VT1-0 titanium alloy during electrolytic saturation and gas-phase saturation are studied. After electrolytic saturation, a 0.4-μm-thick surface layer consisting of δ hydrides with a binding energy of 108 kJ/mol forms in the alloy. The hydride dissociation after electrolytic saturation in heating occurs in the temperature range 320–370°C. After saturation from a gas atmosphere, δ hydrides with a binding energy of 102 kJ/mol form throughout the alloy volume. The dissociation of the hydrides formed during gas-phase saturation in heating occurs in the temperature range 520–530°C. A further increase in the temperature is accompanied by the transformation of titanium from the α into the β modification. At 690–720°C, the phase transformation is completed, and another hydrogen desorption peak appears in a thermally stimulated hydrogen desorption spectrum.     

Influence of Annealing on the Structure and Mechanical Properties of Ultrafine-Grained VT22 Titanium Alloy

Russian Physics Journal - Studies of the evolution of the structural-phase state and changes in the mechanical properties of the ultrafine-grained alloy VТ22 after annealing in the...     

氮流量在高氢氛围中对富硅氮化硅薄膜材料结构及其发光特性的影响

采用等离子体增强化学气相沉积技术,以N₂掺入到SiH₄和H₂的沉积方式,分别在玻璃和N型单晶硅片(100)衬底上制备富硅氮化硅薄膜。通过紫外-可见光吸收光谱、傅里叶变换红外吸收光谱(FTIR光谱)、拉曼光谱和光致发光谱(PL谱)分别表征掺氮硅薄膜材料的带隙、结构及其发光特性的变化。结果表明：在氢气的氛围中,随着氮气流量的增加,氢原子能够对薄膜缺陷起到抑制作用,并使较低的SiH₄/N₂流量比下呈现富硅态,但却不利于硅团簇的形成。随着氮原子的掺入,Si—N键的含量增大,带隙增大,薄膜内微结构的无序度也增大,薄膜出现了硅与氮缺陷相关的缺陷态发光;随着氮原子进一步增加,出现了带尾态发光,进一步讨论了发光与结构之间的关联。这些结果有助于采用PECVD制备富硅氮化硅对材料发光与结构特性的优化。     

Influence of barocryodeformation on the hydrogen concentration and acoustic emission in VT1-0 commercial titanium

The concentration of hydrogen with different binding energies and acoustic emission initiated by indentation in VT1-0 commercial titanium in the initial state and after barocryodeformation are measured. The acoustic parameters are found to correlate with the hydrogen concentration in the material.     

Effect of Small Preliminary Deformation on the Evolution of Elastoplastic Waves of Shock Compression in Annealed VT1-0 Titanium

The evolution of an elastoplastic waves of shock compression in VT1-0 titanium in the as-annealed state and after preliminary compression is measured. A preliminary strain of 0.6% and the related increase in the dislocation density are found to change the deformation kinetics radically and to decrease the Hugoniot elastic limit. An increase in the preliminary strain from 0.6% to 5.2% only weakly changes the Hugoniot elastic limit and the compression rate in the plastic shock wave. The measurement results are used to plot the strain rate versus the stress at the initial stage of high-rate deformation, and the experimental results are interpreted in terms of dislocation dynamics.     

Correction to: The Structure and Properties of Microcrystalline and Submicrocrystalline Titanium Alloy VT1-0 in the Area of the Electron Beam Welding Seam

Russian Physics Journal - There was a misprint in the first author’s affiliation (V. A. Klimenov). It should read National Research Tomsk Polytechnic University instead of National Research...     

Pulsed plasma-immersion ion implantation of aluminum into VT1-0 titanium

The results from investigating the pulsed plasma-immersion ion implantation of aluminum into VT1-0 titanium are presented. It is shown that variations in the elemental and phase composition of surface layers, their microscopic characteristics, and their mechanical properties as a function of implantation time are not monotonous but follow certain patterns. The possibility of interpreting the obtained data in terms of surface modification by metallic clusters with at least ~100 atoms generated in the gas of metal atoms evaporated from cathode spots is discussed.     

Change of the kinetics of shock-wave deformation and fracture of VT1-0 titanium as a result of annealing

The paper presents the results of measurements of shock-wave compression profiles of VT1-0 titanium samples after rolling and in the annealed state. In the experiments, the pressure of shock compression and distance passed by the wave before emerging to the sample surface were varied. From measurements of the elastic precursor decay and compression rate in a plastic shock wave of different amplitudes, the plastic strain and the corresponding shear stresses in the initial and subsequent stages of high-rate deformation in an elastoplastic shock wave are determined. It is found that the reduction in the dislocation density as a result of annealing reduces the hardness of the material but significantly increases its dynamic yield strengh, corresponding to the strain rate above 10⁴ s^–1. With a reduction in the strain rate, this anomalous difference in the flow stresses is leveled off.     

Effect of the Temperature of Megaplastic Deformation in a Bridgman Chamber on the Formation of Structures and the Physicochemical Properties of Titanium (BT1-0)

The formation of regions corresponding to deformational fragments and dynamically recrystallized grains in the structure of the α-phase after torsion under high hydrostatical pressure at room and cryogenic temperatures is determined by means of transmission electron microscopy. Its applicability to describing defective structures of a two-phase mixture model is shown. In optimizing the results from mechanical and corrosion tests, it is found that two rounds of torsion treatment under hydrostatic pressure is sufficient to obtain the best possible properties.     

Optical and Photoluminescent Properties of a Thin Zinc Oxide Film on a Lithium Tantalate Substrate

Optics and Spectroscopy - The results of a study of the structural, optical, and photoluminescent properties of a thin zinc oxide film on a LiTaO3 substrate have been presented. The results of...     

低温制备二氧化钛纳米薄膜及其光伏性能研究

研究一种易实现的低温合成TiO2薄膜电极的方法。实验采用氨水、盐酸和去离子水分别作为无机粘结剂、无水乙醇作为分散剂来合成TiO2浆料,重点研究了粘结剂/分散剂质量比对薄膜制备的影响。采用合成的TiO2电极进行全固态染料敏化太阳能电池的组装。综合浆料粘稠度测试、薄膜形貌表征以及电池时域/频域光电测试等结果,分析了宏观光伏特性与微观载流子输运机制。最终得到最佳的无机粘结剂/分散剂质量比,相应电池的光电转换效率达到1.45%。