Microstructure, Phase Composition, Physical and Mechanical Properties of Titanium Alloy VT23 Hot-Extruded Tube

Macro-, microstructural, fine structure, phase composition, texture and complex of physical and mechanical properties in titanium alloy VT23 (Ti-5.5Al-4.7V-2.5Mo-1.1Cr-0.7Fe, wt. %) tube were studded by the macroanalysis, optical and transmission microscopy, X-ray phase analysis, durometry and microindentation methods. A close relationship between the structural-textural-phase state formed during the extrusion and the obtained level of strength, plastic, durometric properties and the contact modulus of elasticity in a hot-extruded tube has been established.

Formation of Nanostructure and Tool Wear during Cutting Treatment of Titanium Alloy

Methods of the optical metallography, TEM, SEM-technique, tests for hardness and wear resistance are used to investigated the structural - phase transformation in metal blanks from alloy VT23 at cutting treatment in an interval of speeds 2...120 m/min are given. The patterns of interaction of dynamic plastic deformation and destructions on macro-, meso-, micro-and nanolevels are determined. It is shown that the formation in metal blank of modulated high-tensile secondary nanostructures promotes a heightening of a protective wearproofity of treated metal blank, but cutting edge, lowering a wearproofity, of the cutting tool.

Improving of Mechanical Properties of Titanium Alloy VT23 due to Impact-Oscillatory Loading and the Use of Carbon Nano-Solution

Improvement in the mechanical properties of sheet two-phase high-strength titanium alloy VT23 due to impact-oscillatory loading and the use of carbon nanosolutions at room temperature was tested experimentally. It was shown that in addition to obtaining a significant increase in the initial plastic deformation of the alloy, it is possible to strengthen the surface layers of the alloy by a factor of 8.4% at a time via the impulse introduction of energy into the alloy and the use of carbon nanosolutions. Using X-ray photoelectron spectroscopy (XPS), it was first found that strengthening of the surface layers of the titanium alloy at a given load, in line with using a carbon nanosolution, leads to the formation of a mixture of titanium oxide and titanium carbide or oxycarbide of type TiO2−xCx on the surface.

Impact of Dynamic Non-Equilibrium Processes on Fracture Mechanisms of High-Strength Titanium Alloy VT23

The complex analysis of fractures of high-strength titanium alloy VT23 was performed at the macro- and microlevels, and the basic patterns of fracture under static stretching and after the realization of dynamic non-equilibrium processes caused by impact-oscillatory loading and subsequent static stretching were revealed. The morphological regularities in the formation of dimples of tearing and alloy stratification at the macro level were established with the help of 3-D profilometry. The micromechanisms of fracture were numerically characterized by the methods of optical-digital analysis, in particular, by highlighting the bound areas, which are the objects of interest—the dimples of tearing. The analysis of the surface of ductile tearing under different loading conditions at the microlevel was performed by analyzing the parameter distribution patterns of the dimples found on it.

Modes of hardening of a high-strength (α+β)-titanium alloy VT23 for use in aeronautical engineering

New modes of thermal hardening of various semi-finished products made from high-strength titanium alloy VT23 are recommended, and the mechanical and special properties obtained as a result of their research are given.