This research focuses on the stability of three metastableβ titanium alloys – Ti-10V-1Fe-3Al (T i −1013), Ti-10V-2Cr-3Al (T i −102Cr 3) and Ti-10V-2Fe-3Al-B (T i −1023B). In the first stage of the work, new β+ (α+β) heat treatment schemes were designed on the basis of Thermo-Calc® simulations and previous research work and carried out to such an extent that the β phase stability is tuned to the...

This work focuses on the macroscopic behaviour of a large family of first-order phase transitions, including thermoelastic martensitic transformations, which are practically insensitive to thermal fluctuations and need to be driven by an external field. The Random Field Ising Model at T = 0 is used to carry out a detailed study of the dynamics and thermodynamics of this family of fluctuationles...

We study a fully inertial discrete model of a martensitic phase transition which takes into account interactions of first and second nearest neighbors. Although the model is Hamiltonian at the microscale^ it generates a nontrivial macroscopic relation between the velocity of the martensitic phase boundary and the conjugate configurational force. The apparent dissipation is due to the induced ra...

A variational problem arising as a model in martensitic phase transformation including surface energy is studied. It explains the complex, multi-dimensional pattern of twin branching which is often observed in a martensitic phase near the austenite interface. We prove that a Lavrentiev phenomenon can occur if the domain is a rectangle. We show that this phenomenon disappears under arbitrarily s...

The shape memory effect and superelasticity are usually found in alloys exhibiting spontaneous martensitic transformation. Thus it is hard to imagine that such interesting effects can appear in a system without a martensitic transformation. In this Letter we show shape memory and the superelasticity effect in a nonmartensitic Ti48.5Ni51.5 alloy, which has no martensitic transformation but under...

A phase-field theory of transformations between martensitic variants and multiple twinning within martensitic variants is developed for large strains and lattice rotations. It resolves numerous existing problems. The model, which involves just one order parameter for the description of each variant-variant transformation and multiple twinnings within each martensitic variant, allows one to pres...

in this paper, effect of hydrogen diffusion on 2.25cr-1mo steel with ferritic-bainitic and martensitic microstructure has been investigated. hydrogen embrittlement of this steel was investigated by doing experimental such as delayed fracture and slow strain rate tests. result of this research was showed that the steel with martensitic  microstructure strongly affected by hydrogen diffusion and ...

In this chapter the theoretical basics important to understand all aspects of this work are presented. Theoretical concepts that are import for single chapters only are presented accordingly. In the first section, fundamental properties of the martensitic transformation are introduced. The concept of phase compatibility is introduced in the following section. In the last section, the influences...