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Effect of femtosecond laser processing on mechanical properties of plates made of submicrocrystalline VT1-0 titanium alloy is studied using active deformation and fatigue testing involving cantilever bending.

The paper presents the experimental results on thermomechanical stability of the structure and the evolution of microstructure of the type ВТ1-0 nanostructured titanium. The cyclic tests are performed within the temperature range of 30–350°С.

The effect of nanoporosity and the highly dispersed carbide particles that form during screw and lengthwise rolling of VT1-0 titanium on its mechanical and, partly, thermal stability characteristics is revealed and analyzed.

The thermomechanical stability of nanostructured (NS) commercially pure titanium is studied in the temperature range of 20–600°C using the method of dynamic mechanical analysis. It has been found that the maxima observed in the temperature dependence of the loss angle tangent (t = 350–600°C for the analyzed cyclic loading frequencies of 0.33–10 Hz) are of relaxation nature. The measured activation energies of microplastic deformation are close to the corresponding literary data on the experimental activation energies of the grain-boundary sliding under the studied conditions. The thermomechanical stability of NS VT1-0 titanium for medical application has been experimentally estimated up to 1.2 × 106 cycles of loading with cantilever bending at t = 100°C, which is substantially higher than the operating temperature (t = 37°C).

The structure and mechanical properties of nanostructured titanium VT1-0 derived using an ingenious method which combines helical and longitudinal rolling are studied in comparison with the properties of commercial titanium alloys VT6 and VT16, as well as VT1-0 in a coarse-grained state. The mechanical properties of these materials are studied using quasi-static tensile and torsion tests (including finished products, i.e., implants for osteosynthesis), as well as fatigue tests. It is shown that the use of the developed method of severe plastic deformation is an efficient mode for the formation of a high-strength nanostructured state in titanium VT1-0, which exhibits sensitivity to stress concentrators under cyclic loading that is characteristic of titanium alloys and an extremely high reserve of torsional plasticity.

Fundamental propositions of the well-known method of programmed strengthening of crystalline solids are described. It is shown that when mechanical (deformation) and thermal (tempering, annealing, and aging) actions are combined, the loading rate is determined by the rate of diffusion and microshear processes of relaxation of internal stresses in regions of defect accumulation and by the formation of stable complexes as a result of directional diffusion of point defects.

The processes occurring in chromium-nickel steel 08Kh18N10T due to strain aging are studied. The tensile mechanical properties are determined. Relaxation tests and metallographic and x-ray diffraction analyses are performed. The internal energy state of the steel is estimated with the help of acoustic emission.