The article presents the results of research on the software adaptive system for managing the transportation of heavy loads through the automated weight and size control in order to minimize the ...adverse impact of motor vehicles on the roads by creating an information center for managing heavy loads, identifying factors at all stages of the transportation process, searching for an optimal solution for every stage, automating the heavy load transportation planning process and reducing the impact on roads.
This paper reports the results of experiments on superplastic forming (SPF) and pressure welding (PW) performed with sheets of nano- and submicro-crystalline Ti–6Al–4V alloy. The decrease in the mean ...grain size of Ti–6Al–4V alloy sheets from 0.4 to 0.2
μm allows the decrease of the SPF temperature from 750 to 600
°C and the fabrication of cylindrical samples with appropriate shape, bending radius and thickness distribution. Due to the low temperature superplasticity flow stress, sound solid state joint (SSJ) for nanostructured Ti–6Al–4V alloy was obtained at 600
°C. The decrease of the mean grain size to nano- and submicro-crystalline sizes allows the application of the “low temperature superplasticity” for processing hollow components out of Ti–6Al–4V alloy by combining SPF and PW.
This paper reports on investigations of the solid state formability and weldability of Ti-6Al-4V titanium alloy sheet with submicrocrystalline structure (grain size 0·5 and 0·8 μm) under superplastic ...conditions at temperatures of 700 and 800°C. It has been established that the submicrocrystalline condition of the sheet material reduces the temperature of superplastic forming (SPF) by 200°C and of diffusion bonding (DB) by 100°C, compared to the conventional superplastic forming Ti-6Al-4V material with microcrystalline structure (grain size 3 μm). Unlike commercially available sheet, the submicron grained sheet is characterised by isotropic formability. Submicrocrystalline processed Ti-6Al-4V sheet can be successfully used in SPF/DB technology. The temperature range of superplastic forming can be between 700 and 800°C, and diffusion bonding at 800°C.
A Ti–6Al–4V alloy sheet with a submicrocrystalline structure (grain size of 0.3
μm) was produced by multistep isothermal forging followed by flat rolling at temperatures below 650°C. The sheet showed ...a very strong basal texture and isotropic properties in the sheet plane. Room temperature yield strength, ultimate tensile strength, and fatigue limit of the sheet were 1.2–1.3 times higher than that of sheet with micron-sized grains. Sheet with the submicrocrystalline structure showed superplastic properties at temperatures 650–750°C. A complex hollow structure was produced from the sheet by diffusion bonding/superplastic forming at temperatures 750–800°C. The structure had high microstructural homogeneity and high quality of diffusion bonding.
PrF
3
and LaF
3
nanoparticles were synthesized by the hydrothermal method. The size distribution of these nanoparticles in the colloidal solution produced was studied by photon correlation ...spectroscopy. The mean diameter of the nanoparticles was 42 ± 1 nm. During the study of the toxicity of the nanoparticles, the mixture of a colloidal solution of the nanoparticles with cells to be studied was irradiated by 30-mW continuous lasers at wavelengths of 532 and 473 nm. The concentration of salmonella cells in normal saline was 10
6
cell/mL, while that of nanoparticles was 0.1 g/L. The cell survival percentage was 39, 34, and 20% for the irradiation times of 5, 10, and 15 min, respectively, at an optimal laser radiation power density of 0.4 W/cm at a wavelength of 532 nm. It was ascertained that LaF
3
nanoparticles do not possess the property of photoinduced toxicity and the apoptosing effect. Moreover, the property of photoinduced toxicity is not shared by microparticles, in contrast to nanoparticles.
The superplastic forming process of the VT6 titanium alloy three‐layered hollow structures with goffered filler are investigated. Based on the results of experimental studies and on the results of ...finite element modeling, we determine rational parameters of the process such as gas pressure increase rate, when superplastic flow condition is satisfied for ribs, and the processing time is minimal.
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