International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Titanium Ti-6-4 alloy coated with Ni-base material was obtained via Blended Elemental Powder Metallurgy approach by sintering a mixture of laminated powders. Microstructure and phase composition of obtained laminated material were studied, and formation of Ti2Ni phase and multicomponent phase (Ti, Ni, Al, V, C) with E93 crystal cell of space group 227: Fd-3m was established. The intermetallic melt deeply permeated into the Ti-6-4 material at sintering temperature (1250°C) higher than Ti2Ni melting point (942°C), and a dense gradient structure formed. The microstructure, phase composition and properties of obtained gradient material are discussed in detail.

X-ray diffraction analysis studies the formation of a stress-strain state of single-crystal composites LaB6-TiB2 obtained under identical conditions by crucible-free float zone melting (FZM). The composites were obtained using monocrystalline LaB6 substrate seeds with <100>, <110> and <111> orientations. It is shown that indentation-induced deformation in the composite materials obtained by FZM is distinct from the deformation expected in their equilibrium state. This difference arises in part from residual thermal strains in both phases of the composites in a FZM -grown state. Interplay between residual thermal deformations and external mechanical deformation results in a complex distribution of dilatational strain in the LaB6 matrix and TiB2 fibers and differs in composites of different orientations. Reversal sign of the stress-strain state (e.g., alternating tensile/compressive/tensile in central part of the cross-section area) is observed predominantly in the matrix LAB6 and the TiB2 fibers of the composite with the orientation <111>. In the composite with the orientation <100>, this change in the deformation sign was not observed. The size and spread of cracks after indentation-induced deformation shows a decrease in microhardness in FZM -grown composites of <111> significantly more (40%) than in composites with a orientation of <100> (10%) compared with an equilibrium state.