Kinetic regularities of high-temperature interaction of titanium alloys with oxygen-medium
Journal Title: Український журнал із машинобудування і матеріалознавства - Year 2018, Vol 4, Issue 2
Abstract
Titanium alloys are widely used in various aerospace, marine, chemical industries, medical, and military applications because these alloys have high specific strength, high Young’s modulus, and excellent corrosion resistance. In particular, when a lot of organic composite materials such as carbon fibre-reinforced plastics (CFRP) are applied to aircraft components to decrease the weight reduction, titanium materials are also used because their thermal coefficient of expansion is similar to that of CFRP and titanium is not subject to damage by galvanic corrosion in contact with CFRP materials. Oxygen can dissolve in titanium to form an interstitial solid solution in a large amount (34 at.% in alpha titanium), it shows a strong hardness and mechanical strengthening on titanium matrix. Therefore, instead of expensive rare metals such as vanadium (V), oxygen (O) is usually used as a attractive interstitial solid solution strengthening element. Results of experimental investigations of the influence of a oxygen-containing gaseous medium on the kinetics of interaction of titanium alloys of different structural classes (α-, pseudo-α, (α+β)) are presented in this paper. It is established that under the same conditions of saturation (T, τ, P) the hardened layers of various parameters (H, l) are formed on the titanium alloys. The monophase α-titanium alloys VT1-0, VT5 and pseudo-α-alloy ОТ4-1 are the most sensitive to the conditions of gas-saturation: gain of surface hardness and its gradient in the hardened layer increases sufficiently. With increasing of β-phase (OT4®VT16) changing of the parameters of CTT has less influence on the hardness of surface layer, but the depth of the hardened zone is being increased with increasing of the temperature and exposure time.
Authors and Affiliations
Vasyl Trush
Propagation of Plane Elastic-Tough-Plastic Waves in the Material with Yield Delay
The use of electromechanical model of ideal elastic-tough-plastic material with yield delay while investigating the propagation of plane one-dimensional waves is being considered. The materials being investigated possess...
Theoretical foundations for the development of experimental equipment for determining the load capacity of speed change devices
The article gives the theoretical base for construction of equipment for experimental research of static, kinematic and dynamic characteristics of devices for speed change by epicyclic gear trains with closed circuit hyd...
Application of wear-resistant coating by electrospark alloying method using an eutectic electrode material
Analysis of the literature database connected with the usage of an electro-spark alloying (ESA) for tool hardening has been carried out in the article. Necessity of developing a new tungstenless electrode materials with...
Calculation of wave fields in a layered half-space with absorption based on the Thomson-Haskell method
This article is devoted to the development of calculation method of seismic waves on the free surface of a horizontally-layered half-space, which are perturbed by local sources. Previous obtained relations for scalar pot...
Substantiation of inertial, stiffness and excitation parameters of vibratory lapping machine with linear oscillations of laps
Problem statement. Designing and manufacturing of efficient resonant vibratory lapping machines with linear oscillations of laps demand an accurate and detailed calculation of parameters of their elastic systems and elec...