Elastoplastic properties of a low-modulus titanium-based β alloy

The elastoplastic properties (elastic modulus, amplitude-independent damping ratio, microplastic flow stress) of a Ti-26Nb-7Mo-12Zr titanium β alloy are determined using an acoustic resonance method. The effect of the strain during thermomechanical treatment on the structural features of the micro-crystalline alloy and, hence, its elastoplastic properties is analyzed.     

The Influence of Mechanical Treatment on the Surface Relief of a Fe77Ni1Si9B13 Metal Glass

Physics of the Solid State - The micro- and nanoreliefs of the loaded surfaces of a Fe77Ni1Si9B13 metal glass are probed via scanning tunneling and atomic force microscopies, scanning electron...     

Evolution of a Defect Structure during Creep Tests of Ultrafine-Grained Metals and Alloys Produced by Severe Plastic Deformation

Physics of the Solid State - The structural factors that lead to a decrease in the mechanostability of ultrafine-grained (UFG) metals and alloys during creep tests at increased temperatures have...     

Mechanical properties and structural features of nanocrystalline titanium produced by cryorolling

A broad spectrum of physicomechanical properties of the VT1-0 nanocrystalline titanium produced by cryomechanical fragmentation of the grain structure using rolling at a temperature close to liquid-nitrogen temperature has been studied. It has been found that the mechanism of grain refinement is associated with grain fragmentation by twins. Exactly the twin nature of internal interfaces (crystallite boundaries) provides the thermal and structural stability of nanocrystalline titanium produced by cryomechanical grain fragmentation in the temperature range to ～500 K. It has been assumed that the observed decrease in the titanium density due to cryorolling is associated with a number of factors (high density of introduced dislocations, nanopore formation, and changes in titanium lattice parameters).     

Kinetics of defect accumulation and duality of the weller curve in gigacycle fatigue of metals

We propose a model describing the kinetics of accumulation of defects under cyclic loading in metals. Analysis of experimental data on the initial defect distribution and of the role of the free surface of the sample in straining makes it possible to explain the features of generation of fatigue cracks in the bulk, which is typical of the gigacycle fatigue regime at a low stress level. The duality of the Weller curve in the gigacycle fatigue regime is attributed to the emergence of a fine-grain region in the form of a dissipative peaking structure in the defect ensemble.     

Defect structure and thermomechanical stability of nano- and microcrystalline titanium obtained by different methods of intense plastic deformation

Mechanical stability under prolonged loading and thermostability under annealing have been studied for nano- and microcrystalline titanium obtained by different methods of intense plastic deformation. The effect of nanoporosity and the fraction of high angle boundaries formed due to intense plastic deformation has been revealed and analyzed. It has been established that, depending on the loading or the annealing temperature, thermomechanical stability of titanium can be affected, apart from the above structural characteristics, by either twin grain boundaries or titanium-carbide disperse particles.     

Internal friction,Young’s modulus,and electrical resistivity of submicrocrystalline titanium

The variation of the internal friction, Young’s modulus, and electrical resistivity of two grades of polycrystalline titanium (VT1-0 and Grade 4) in the area of low temperatures (100–300 K) as depending on the initial structure and subsequent severe plastic deformation converting the material into the submicrocrystalline structural state in relation to the grain size is studied. The maximum of the internal friction is detected in submicrocrystalline titanium, which is interpreted as a Bordoni peak. All the studied characteristics are sensitive indicators for a nonequilibrium state of the grain boundaries after the deformation. The effect of the initial structure of the metal on its properties after the severe deformation is revealed.     

A Study of the Influence of Irradiation of Carbon Diamond-Like Coatings with Nanosecond Laser Pulses on Their Structural-Phase Composition and Tribological Properties

Russian Physics Journal - Using the methods of Raman spectroscopy, optical metallography and scanning electron microscopy, combined with the measurements of tribological characteristics, special...     

Mechanical properties,density, and defect structure of VT1-0 titanium after intense plastic deformation due to screw and longitudinal rollings

The influence of screw rolling combined with standard methods of mechanothermal treatment on the homogeneity of the forming submicrocrystalline structure, density, and mechanical performance of VT1-0 commercial titanium is studied. It is shown that such a treatment carried out within optimal temperature and strain rate intervals (special deformation conditions) causes minor softening of the material and can be effectively used to form a homogeneous submicrocrystalline structure with high strength and elastoplastic properties.