"21340" . "Str\u00E1sk\u00FD, J." . . . "Mu\u0161\u00E1lek, R." . "\u010Capek, Ji\u0159\u00ED" . . "I" . . . "Study of microstructure, hardness and residual stresses in FeB and Fe2B ultrahard layers" . "3"^^ . "Boriding; surface hardening; iron borides; tooth-shaped microstructure; residual stresses"@en . . . . . "Study of microstructure, hardness and residual stresses in FeB and Fe2B ultrahard layers"@en . "RIV/68407700:21340/14:00227861!RIV15-MSM-21340___" . . . "Pala, Zden\u011Bk" . . "Boriding is a comparatively simple method of achieving ultra-hard surface on metals via thermo-chemical diffusion-based mechanism. For irons, the resulting surface hardness can be in the vicinity of 2000 HVN and, in particular, two distinct crystalline phases, i.e. tetragonal Fe2B, which has three polymorphs with space groups I-4/mcm or I-42m, and orthorhombic FeB (Pbnm) originate in the surface layer penetrated by boron ions. The spatial layout of the phases is usually such that the more brittle FeB is on the surface and the needles in deeper layers are grains of Fe2B. Even though differences in thermal expansion coefficients play an important role, macroscopic residual stresses or their spatial distribution in the altered layer are significant from the viewpoint of the new ultra-hard surface durability. In our contribution, we have studied microstructure, hardness and spatial distributions of both phase composition and residual stresses in samples exhibiting either single phase Fe2B or duplex Fe2B-cum-FeB character. The indispensable knowledge of elastic constants used in stresses calculation from measured deformations by XRD were gained from the refined lattice parameters of both iron borides employing density functional theory implemented in CASTEP software by Material Studio In all studied cases, Fe2B has only minor occurrence of preferred orientation and the evaluated residual stresses have compressive character gradually decreasing from its maximal value on the very surface. However, the pronounced fibre 002 texture of FeB epitomized a hurdle for employment of standard algorithms in XRD stress analysis and called for unorthodox computations which took into account the volume fraction of materi\u00E1l with texture and the texture quantitative characterization by pole figures and ODF." . "[658A5B0B985E]" . . "6"^^ . "Study of microstructure, hardness and residual stresses in FeB and Fe2B ultrahard layers" . "RIV/68407700:21340/14:00227861" . "Boriding is a comparatively simple method of achieving ultra-hard surface on metals via thermo-chemical diffusion-based mechanism. For irons, the resulting surface hardness can be in the vicinity of 2000 HVN and, in particular, two distinct crystalline phases, i.e. tetragonal Fe2B, which has three polymorphs with space groups I-4/mcm or I-42m, and orthorhombic FeB (Pbnm) originate in the surface layer penetrated by boron ions. The spatial layout of the phases is usually such that the more brittle FeB is on the surface and the needles in deeper layers are grains of Fe2B. Even though differences in thermal expansion coefficients play an important role, macroscopic residual stresses or their spatial distribution in the altered layer are significant from the viewpoint of the new ultra-hard surface durability. In our contribution, we have studied microstructure, hardness and spatial distributions of both phase composition and residual stresses in samples exhibiting either single phase Fe2B or duplex Fe2B-cum-FeB character. The indispensable knowledge of elastic constants used in stresses calculation from measured deformations by XRD were gained from the refined lattice parameters of both iron borides employing density functional theory implemented in CASTEP software by Material Studio In all studied cases, Fe2B has only minor occurrence of preferred orientation and the evaluated residual stresses have compressive character gradually decreasing from its maximal value on the very surface. However, the pronounced fibre 002 texture of FeB epitomized a hurdle for employment of standard algorithms in XRD stress analysis and called for unorthodox computations which took into account the volume fraction of materi\u00E1l with texture and the texture quantitative characterization by pole figures and ODF."@en . "Kyncl, Ji\u0159\u00ED" . . "48301" . "Study of microstructure, hardness and residual stresses in FeB and Fe2B ultrahard layers"@en . . . . . "Fojt\u00EDkov\u00E1, Jaroslava" .