Increase in Reliability of Metal Articles with Impulse Current Effect

Investigation in duration effect of powerful electric current impulses on variation process of some properties of steels 40 and 45 and titanium alloy VT1-0 working in the high-cycle fatigue regimes was performed and nature of such an effect was detected in the research. By measuring the ultrasonic speed it was shown that electric current effect results in increase in reliability of articles

Increase in Reliability of Metal Articles with Impulse Current Effect

Investigation in duration effect of powerful electric current impulses on variation process of some properties of steels 40 and 45 and titanium alloy VT1-0 working in the high-cycle fatigue regimes was performed and nature of such an effect was detected in the research. By measuring the ultrasonic speed it was shown that electric current effect results in increase in reliability of articles

Mathematical Modelling Stress Distribution in a Metallic Plate with an Asymmetrical Notch

The paper is focused on analyzing σх, σy, τхy, arising in a steel plate with stress raisers when alternate bend fatigue. The research based on the finite-element method is carried out by software ANSYS. Stress distribution is studied in two planes

Structural and phase changes under electropulse treatment of fatigue-loaded titanium alloy VT1-0

The effect of electropulse treatment (EPT) of titanium alloy VT1-0 on the change of its fatigue life, structure and phase composition has been investigated. The study has shown that EPT improves the fatigue life by 1.3 times. Methods of TEM were used to analyze changes of the structure and phase composition of samples subjected to EPT and endurance testing. In the process of fatigue tests involving cantilever bending, a grain and sub-grain structure is formed in the surface of commercially pure titanium. The study has disclosed that the surface layer of the material has a multi-phase structure. Nano-crystal grains are formed by α-titanium. Oxide phase of titanium has been revealed, which is located along the crystallite boundaries of α-titanium. Particles of oxide phase have been identified exclusively in the top nano-structured layer. In the rest of the sample there are no particles of this phase. EPT causes dimensional changes of oxide phase particles and many-fold dimensional changes of crystallites in the surface layer. Owing to this treatment there are less internal stress concentrators in the surface layer of the material, which results, therefore, in cut down on probable spots of crack origination. Keywords: Titanium alloy, Electropulse treatment, Microstructure, Phase composition, Fatigue strengt