The investigation of electronic properties of Ti-based alloys

Abstract

Abstract. The self-consistent band structure calculations of the ordered and disordered intermetallic titaniumbased alloys were performed using full-potential linearized augmented plane wave (FLAPW) method and Korringa-Khon-Rostoker -coherent potential approximation (KKR-CPA) The electronic structure of the (001) surfaces are also calculated. The alteration of the electronic properties in the three TiMe series (Me=Fe, Co. Ni. Ru, Rli, Pd, Os, Ir, Pt) are discussed in the dependence of a number of valence electrons. The changes of the electronic structure during martensitic transformation, with disordering and alloying are analyzed. The calculated emission, absorption, electron energy loss spectra and optical properties are found to be in good agreement with experiment.

Physical metallurgy of Ti–Ni-based shape memory alloys

“…A number of first-principles calculations or electronic calculations [203,210,83,218,220] are devoted to explain the parent phase instability in terms of certain electronic effect. The 1/3 phonon dip and its temperature dependence for Ti-Ni was reproduced by Zhao and Harmon [203] by considering the electron-phonon coupling of nested electronic states on the Fermi surface.…”

First-principles study to explore the possibility of inducing martensitic transformation in ordered B2 TiRu phase by alloying with Pd

“…10,11,16 This highly stable B2 phase behaviour is also found in other transition metals belonging to group VIII of the periodic table of elements. [16][17][18][19] Upon comprehensive study of the Ti-Ru system, Murray 20 reported that the equiatomic TiRu binary compound crystallizes in the B2type crystal structure with space group Pm-3m of an ordered body centered cubic (BCC) CsCl-type. 17,18,21 This B2 phase is a sole high temperature intermetallic phase of the TiRu system with lattice parameter ranging from 3.06 to 3.076 Å, and it undergoes congruent melting at 2130°C.…”

“…[16][17][18][19] Upon comprehensive study of the Ti-Ru system, Murray 20 reported that the equiatomic TiRu binary compound crystallizes in the B2type crystal structure with space group Pm-3m of an ordered body centered cubic (BCC) CsCl-type. 17,18,21 This B2 phase is a sole high temperature intermetallic phase of the TiRu system with lattice parameter ranging from 3.06 to 3.076 Å, and it undergoes congruent melting at 2130°C. CsCl-type titanium intermetallic compounds are currently the most attractive hydrogen storage materials.…”

Ab-initio techniques, VASP and CASTEP, are used to investigate the electronic properties of B2 compounds formed between Ti and group VIII elements - a comparative study

“…The above-mentioned Group IV transition metals form Cesium-Chloride (CsCl) intermetallic compounds with Group VIIIB and IB transition metals due to limited mutual solubility during solidification [8,9]. These compounds crystallize congruently from liquid to an ordered B2 which is a high-temperature austenite phase at compositions close to 50:50 atomic percentage (at.…”

“…%). Due to their high melting points, some of these compounds (such as Ti50Ru50, Ti50Os50 and Ti50Fe50) are mostly referred to as refractory intermetallics [8,9,10]. Typically, most of these B2 compounds become unstable and undergo martensitic transformation to crystal structures of lower symmetry at lower temperatures [1,11,12].…”