Jacek Krawczyk

University of Silesia in Katowice · Institute of Materials Engineering

The distributions of the lattice parameter of the γ′-phase (aγ′) and angular components of the primary crystal orientation along the lines parallel to the main axis of the single-crystalline CMSX 4-cored turbine blades were studied. The studies were carried out on the regions of the blades located far from the selector and its continuer extension (...

The γ′ lattice parameter aγ′ and the α angle defining the primary crystal orientation of the single-crystalline cored turbine blades made of CMSX-4 superalloy were measured in the areas located near the selector situated asymmetrically, considering the top view of the blade. The distributions of the aγ′ and the α angle were determined along the lin...

The dendritic structure and the distribution of the γ′‑phase lattice parameter (aγ′) along selected lines of the longitudinal section in a model single-crystalline blade made of CMSX-4® nickel-based superalloy were studied. It was established that there is a correlation between the value of the aγ′ and the predomination of initial or ending fragmen...

Single-crystalline cored CMSX-4 blades obtained at a withdrawal rate of 3 mm/min by the vertical Bridgman method were analyzed. The dendritic structure and crystal orientation near the cooling bores of the blades were studied through Scanning Electron Microscopy, the X-ray diffraction measurements of α and β angular components of the primary crysta...

The areas located near the cooling bores of single-crystalline cored turbine blades made of nickel-based CMSX-4 superalloy were studied. The blades were solidified by the vertical Bridgman technique in the industrial ALD furnace. Longitudinal sections of the blades were studied by Scanning Electron Microscopy, X-ray diffraction topography, X-ray di...

The roots of cored single-crystalline turbine blades made of a nickel-based CMSX-4 superalloy were studied. The casts were solidified by the vertical Bridgman method in an industrial ALD furnace using the spiral selector and selector continuer situated asymmetrically in the blade root transverse section. Scanning electron microscopy, the Laue diffr...

In the present study, the dendrites deflection mechanism from the mold walls were subjected to verification regarding its heat-treated turbine rotor blades. The number of macroscopic low-angle boundaries created on the cross-section of the blades’ airfoil near the tip was experimentally determined and compared to the number of low-angle boundaries...

The variation of the crystal orientation and the dendrite array generated in the root of the single-crystalline (SX) turbine blades made of CMSX-4 superalloy were studied. The blades with an axial orientation of the [001] type were solidified by the industrial Bridgman technique using a spiral selector at a withdrawal rate of 3 mm/min. The analysis...

The thin-walled airfoil areas of as-cast single-crystalline turbine blades made of CMSX-4 superalloy were studied. The blades were produced by the industrial Bridgman technique at withdrawal rates of 2, 3 and 4 mm/min. The angle between the [001] crystallographic direction and blade axis, related to the primary orientation, was defined by the Ω-sca...

An analysis of the defects in the vicinity of the selector–root connection plane occurring during the creation of single-crystalline turbine blades made of CMSX-6 Ni-based superalloy was performed. X-ray diffraction topography, scanning electron microscopy, and positron annihilation lifetime spectroscopy were used. Comparing the area of undisturbed...

Single-crystalline superalloy CMSX-4 is studied in the as-cast state and after heat treatment, with material being taken from turbine blade castings. The effect of the heat treatment on the defect structure of the root area near the selector/root connection is emphasized. Multiscale analysis is performed to correlate results obtained by X-ray topog...

The as-cast single-crystalline turbine blades made of CMSX-4 superalloy were studied. The blades were obtained by the Bridgman technique at a withdrawal rate of 5mm/min. The as-cast samples were prepared by cutting the blade root with a fragment of selector. The dendritic structure of obtained samples was studied by Scanning Electron Microscopy. Th...

The single crystal turbine blades of aircraft engine were obtained by directional solidification of Ni-based superalloy via Bridgman technique at withdrawal rate of 5 mm/min. The CMSX-4 industrial alloy were used for crystallization. After crystallization the blades were subjected to heat treatment. The Laue diffraction, X-ray diffraction topograph...

The single crystal turbine blades made of CMSX-4 nickel-based superalloy were studied. The turbine blades were obtained by the Bridgman technique with withdrawal rate of 5 mm/min. The samples, cut-off from root part of blades and containing the fragment of the selector, were studied. The effect of selector geometry on the dendrites growth and defec...

The microstructure of as-cast cored turbine blades roots, made of the single-crystal CMSX-4 nickel-based superalloy was investigated. Analysed blades were obtained by directional solidification technique in the industrial ALD Bridgman induction furnace. The investigations of the microstructure of blades roots were performed using SEM and X-ray tech...

The growth morphology and arrangement of tungsten and β-phase (Al (Fe, Cu)) in Al‑Cu‑Fe‑W alloy were analyzed. The composition of Al65Cu20Fe14W1 (at.%) was used for preparation of ingots containing the icosahedral quasicrystalline phase.The ingots were obtained in a two-stage process. At the first stage the induction melting of the elements and pre...

The composites were obtained by the Bridgman method through solidification of Al61Cu27Fe12 alloy (numbers indicate at.%). The microstructure of composites with crystal matrix and quasicrystal reinforcement was studied. The crystalline β-phase was the matrix and the quasicrystaline i-phase was the reinforcement of obtained composites. The shape and...

We studied surface decorations of faceted icosahedral Al-Cu-Fe and decagonal Al-Cu-Co single quasicrystals by the scanning electron microscopy using primary and secondary electrons. Both types of single quasicrystals exhibited decorations on their facets, however the character of the decorations was totally different. Three kinds of decorations has...

The microstructure of Al65Cu20Fe14 (numbers indicate at.%) alloy doped with 1 at.% of W was studied. The selected alloy composition should allow to obtain the quasicrystalline icosahedral phase after solidification process. The bulk samples were obtained in two stages. At first, the synthesis of alloy through premelting of component elements in ind...

The composites of Al61Cu27Fe12 alloys containing quasicrystalline and crystalline phases (CQ composites) were obtained by the Bridgman method. The morphology of composites crystallized with different solidification rates was studied. The solidification rate influence on fibrous reinforcement morphology was analyzed. The microsections for analysis w...

The composites of Al-Cu-Fe alloys with fibrous reinforcement, containing quasicrystals, e.i. crystal-quasicrystal composites (CQ composites) were studied. The composites were obtained in situ by the Bridgman method. The plate-like samples were studied by tensile test performed up to rupture. Tensile fracture surface of composite and reinforcement f...

The composite based on Al-Cu-Co alloy system obtained by directional solidification was characterized. T matrix phase of Al0.72Cu0.27Co0.01 and D reinforcement phase of Al0.64Cu0.2Co0.16 were identified by X-ray powder diffraction (XRD). The composite was also analyzed by light optical microscope followed by scanning and transmission electron micro...

Microstructure of terminal area of Al65Cu32.9Co2.1 ingots (numbers indicate at.%), obtained via directional solidification was studied. Scanning Electron Microscopy, Transmission Electron Microscopy and X-ray powder diffraction were applied. Point microanalysis by Scanning Electron Microscope was used for examination of chemical compositions of all...

The microstructure of Co0.75Ni0.25Si2 solid solution, obtained by two different techniques was studied. The solidification processes were conducted using Bridgman and Czochralski methods. The processes were conducted under atmospheric pressure and in the helium atmosphere. Various pulling down (Bridgman method) and pulling up (Czochralski method) r...

Microstructure of terminal area of Al 65 Cu 32.9 Co 2.1 ingots (numbers indicate at.%), obtained via directional solidification was studied. Scanning Electron Microscopy, Transmission Electron Microscopy and X-ray powder diffraction were applied. Point microanalysis by Scanning Electron Microscope was used for examination of chemical compositions o...

Quasicrystalline as well as crystalline faceted single grains of four phases were obtained during directional crystallisation of an Al–Cu–Fe alloy by the Bridgman technique. The monoclinic λ phase, Al13(Cu, Fe)4, dominating at high temperatures formed single-crystal lamellae 0.5 mm to 1 mm thick. A second type of attractive morphological form exhib...

Morphological details and chemical composition of whisker-like crystals (W-LCs) were studied. The W-LCs were grown on Al2O3 substrate as a result of evaporation of Al65Cu26Co9 alloy. Morphologically diverse W-LCs formed groups in the shape of brushes. The two-phase nature of W-LCs was revealed. The W-LCs consisted of an intermetallic on the Al matr...

Fibre-reinforced composites were produced by the modification of the static horizontal Bridgman method. The single-crystalline composite matrix consisted of the tetragonal T phase (Al72Cu27Co1). Decagonal quasi-crystal D phase (Al64Cu20Co16) was the reinforcement in the form of fibres parallel to the solidification direction. These fibres were surr...

The microstructure of a composite containing a quasicrystal phase, i.e. so-called crystal–quasicrystal (CQ) composite, was studied. The CQ composite was obtained by the Bridgman method via solidification of Al61Cu27Fe12 alloy (numbers indicate at%). The process was conducted at a pull out rate of v = 0.07 mm/min. The average temperature gradient in...

The columnar composites obtained "in situ" through solidification of Al(61)Cu(27)Fe(12) alloy by the Bridgman method were studied. It has been verified that the matrix consisted of cubic single crystal beta phase and the reinforcement of icosahedral quasicrystal psi phase and monoclinic crystal lambda phase, which have the form of rods. This kind o...

Crystal-quasicrystal columnar composites (CQ composites) of Al-Cu-Fe alloy subject to tensile strain at room temperature were studied by the reflective X-ray topography. In those composites singlecrystalline beta phase occurred as the matrix and rods consisting of quasicrystalline psi phase and crystalline lambda phase as the reinforcement. X-ray t...

The subject of the study is the composite material of CoSi2-Si eutectic composition. The influence of crystallization speed on microstructure was examined. The ingots were obtained using Bridgman method. Three different pulling down speeds of crucibles with melted charges were applied. The prepared samples were subjected to metallographic, X-ray, T...

The main goal of paper was obtaining of solid solution Co1-xFexSi2 crystals from liquid phase by Bridgman method. There are presented features and quality parameters of obtained ingots. It was found that the substitutional solid solution Co1-xFexSi2 crystals can be obtained only for x = 1at.% Fe.

The main goal of paper was obtaining of solid solution Co 1-xFexSi2 crystals from liquid phase by Bridgman method. There are presented features and quality parameters of obtained ingots. It was found that the substitutional solid solution Co 1-xFexSi2 crystals can be obtained only for x = 1at.%Fe.