MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AMORPHOUS/CRYSTALLINE DUCTILE LIQUID IMMISCIBLE Fe-Si-B-In ALLOY PRODUCED BY TWO-COMPONENT MELT-SPINNING

The two-component melt-spun (TCMS) Fe71.25Si9.5B14.25In5 alloy was produced from Fe75Si10B15 and Fe67.5Si9B13.5In10 alloys. The microstructure of the TCMS alloy was investigated by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). A tensile test of the alloy resulted in a tensile strength of Rm = 1040 MPa, yield strength Re = 919 MPa, total plastic elongation etot = 3.29%, and traces of plastic deformation on the surface of the Fe-Si-B-In TCMS sample. Microstructural analysis of the amorphous/crystalline composite and tensile sample free surface show the reason for the ductility of the sample in relation to the Fe75Si10B15 alloy

Mechanical properties of Ni-Fe-Cu-P-B alloy produced by two component melt spinning (TCMS)

The aim of this work was to investigate the microstructure and mechanical properties of the two-component melt-spun (TCMS) alloy produced from Ni40Fe40B20 and Ni70Cu10P20 melts. The Ni40Fe40B20, Ni70Cu10P20, Ni55Fe20Cu5P10B10 alloys were arc-melted. Then the alloys were melt-spun in the two different ways i.e.: by casting from a single-chamber crucible and from the two-chamber crucible. All of the above mentioned alloys were processed in the first way and the Ni40Fe40B20 and Ni70Cu10P20 were simultaneously cast on the copper roller from the two-chamber crucible. The microstructure of the alloy was studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) and light microscopy. The mechanical properties were investigated using tensile testing and nanoindentation. The two-component melt-spun (TCMS) amorphous Ni55Fe20Cu5P10B10 alloy present hardness, tensile strength and Young modulus on the significantly higher level than for a single phase amorphous Ni55Fe20Cu5P10B10 alloy and slightly below the corresponding values for the Ni40Fe40B20

INVESTIGATIONS OF MICROSTRUCTURE AND PHASE TRANSFORMATIONS OF Fe71.25Si9.5B14.25In5 ALLOY

The aim of this work was to study the microstructure and high-temperature phase transformations of the Fe71.25Si9.5B14.25In5 alloy. The alloy was remelted in a resistance furnace, and a sequence of melting and crystallization at a range of high temperatures was observed using a mid-wave infrared MWIR camera. The alloy was also investigated by differential thermal analysis (DTA). The microstructure of the alloy was studied using a scanning electron microscope SEM with an energy dispersive spectrometer (EDS). The results show that there is a clear partition into two liquids in the studied alloy. The ingot microstructure presents very strong segregation into the eutectic regions enriched in the Fe-Si-B and In-rich regions

MICROSTRUCTURE AND PHASE COMPOSITION OF THE Ni-Si-B-Ag-BASED PLASMA SPRAY DEPOSIT

The aim of this work is to study the possibility of obtaining an amorphous-crystalline composite starting from Ni-Si-B-based powder grade 1559-40 and silver powder. The process of plasma spray deposition was performed on a water-cooled copper substrate. The cooling rate was assessed using a mid-wave infrared MWIR camera. The microstructure of the deposit was studied using scanning electron microscope SEM with an energy dispersive spectrometer EDS. Phase identification was performed using X-ray diffraction XRD. The studies confirmed an amorphous-crystalline microstructure of the deposits. The predominant constituent of the microstructure was amorphous regions enriched in Ni, Si, and B, while the other constituent was Ag-rich crystalline inclusions identified as a face-centered cubic fcc

Amorphization and liquid state separation in Ni80-2xCuxFexP20 alloys Amorfizacja i podział w stanie ciekłym w stopach Ni80-2xCuxFexP20 /

Tyt. z nagłówka.Bibliogr. s. 52-[54].The aim of the work is to study the ability and potential of glass formation in Ni-Fe-Cu-P alloys. A series of alloys were produced in arc furnace (i.e. Ni70Fe5Cu5P20, Ni60Fe10Cu10P20, Ni50Fe15Cu15P20, Ni40Fe20Cu20P20, Ni30Fe25Cu25P20, Ni20Fe30Cu30P20). The primary microstructure of the ingots was studied. The ribbons in as-melt-spun state were characterized by X-ray diffraction (XRD). The Ni70Fe5Cu5P2, Ni60Fe10Cu10P20 melt-spun alloys were found to be amorphous. For higher copper and iron concentrations a crystalline structure was obtained after melt spinning. This correlated with the tendency for the formation of the Fe-based phases enriched in P and Cu-based poorly alloyed phases which resulted in the formation of crystalline microstructure in melt-spun ribbons. For higher concentration of Fe and Cu, microstructures of the alloys contained constituents resultant from a tendency for separation in the liquid state. It is observed that the formation of the crystal line melt-spun ribbons is caused by the attraction of phosphorus by iron and the formation of copper-based fcc phase.Celem pracy było zbadanie podatności na zeszklenie oraz możliwości wytworzenia struktury szklistej w stopach wieloskładnikowych Ni-Fe-Cu-P. W piecu łukowym wytworzono serię stopów (tzn.: Ni70Fe5Cu5P20, Ni60Fe10Cu10P20, Ni50Fe15Cu15P20, Ni40Fe20Cu20P20, Ni30Fe25Cu25P20, Ni20Fe30Cu30P20). Badano strukturę pierwotną wlewków. Taśmy w stanie po odlewaniu na wirujący bęben badano za pomocą dyfrakcji rentgenowskiej. Stwierdzono, że stopy Ni70Fe5Cu5P20, Ni60Fe10Cu10P20 odlewane na wirujący bęben były amorficzne. Dla stopów o wyższych zawartościach miedzi i żelaza po odlewaniu na wirujący walec otrzymano strukturę krystaliczną. Fakt ten można powiązać z tendencją do tworzenia faz na osnowie żelaza wzbogaconych w fosfor oraz zubożonych w pozostałe składniki stopowe faz na osnowie miedzi,które przyczyniły się do tworzenia w odlewanych taśmach mikrostruktury krystalicznej. Dla wyższych zawartości żelaza i miedzi, mikrostruktury stopów zawierały składniki fazowe powstające w efekcie tendencji stopów do podziału fazowego w stanie ciekłym. Zaobserwowano, że tworze nie krystalicznych taśm jest spowodowane przez przyciąganie fosforu przez żelazo oraz tworzenie bogatej w miedź fazy o strukturze regularnej ściennie centrowanej.Dostępny również w formie drukowanej.SŁOWA KLUCZOWE: materiały amorficzne, amorfizacja, dyfrakcja rentgenowska, transmisyjna mikroskopia elektronowa. KEYWORDS: amorphous materials, amorphization, X-ray diffraction, transmission electron microscopy

Preparation, Characterization and Magneto-Optical Properties of Sm-Doped Y₂O₃ Polycrystalline Material

In this paper, physicochemical properties of pure Y2O3 and samarium (Sm)-doped Y2O3 transparent ceramics obtained via arc plasma melting are presented. Yttria powder with a selected molar fraction of Sm was first synthesized by a solid-state reaction method. High transparent yttria ceramics were obtained by arc plasma melting from both the pure and Sm oxide-doped powders. The morphological, chemical and physical properties were investigated by X-ray diffraction and scanning electron microscopy. The optical band gap was calculated from the absorption spectra so as to understand the electronic band structure of the studied materials. Samples indicate a series of luminescence bands in the visible region after excitation by laser light in the range from 210 to 250 nm. Magneto-optical measurements were carried out in the 300–800 nm range at room temperature. It can be seen that a maximum Verdet constant ca. 24.81 deg/T cm was observed for 405 nm and this value decreases with increasing wavelength. The potential usefulness of the polycrystalline material dedicated to optics devices is presented

AMORHIZATION AND LIQUID STATE SEPARATION IN Ni80-2xCuxFexP20 ALLOYS

The aim of the work is to study the ability and potential of glass formation in Ni-Fe-Cu-P alloys. A series of alloys were produced in arc furnace (i.e. Ni70Fe5Cu5P20, Ni60Fe10Cu10P20, Ni50Fe15Cu15P20, Ni40Fe20Cu20P20, Ni30Fe25Cu25P20, Ni20Fe30Cu30P20). The primary microstructure of the ingots was studied. The ribbons  in as-melt-spun state were characterized by X-ray diffraction (XRD). The Ni70Fe5Cu5P20, Ni60Fe10Cu10P20 melt-spun alloys were found to be amorphous. For higher copper and iron concentrations crystalline structure was obtained after melt spinning. This correlated with the tendency for the formation of  the Fe-based phases enriched in P and Cu-based poorly alloyed phases which resulted in formation of crystalline microstructure in melt-spun ribbons. For higher concentration of Fe and Cu, microstructures of the alloys contained constituents resultant from tendency for separation in the liquid state. It is observed that formation of the crystalline melt-spun ribbons is caused by attraction of phosphorus by iron and formation of copper-based fcc phase

Extremely Fast and Cheap Densification of Cu₂S by Induction Melting Method

The aim of this work was to obtain dense Cu2S superionic thermoelectric materials, homogeneous in terms of phase and chemical composition, using a very fast and cheap induction-melting technique. The chemical composition was investigated via scanning electron microscopy (SEM) combined with an energy-dispersive spectroscopy (EDS) method, and the phase composition was established by X-ray diffraction (XRD). The thermoelectric figure of merit ZT was determined on the basis of thermoelectric transport properties, i.e., Seebeck coefficient, electrical and thermal conductivity in the temperature range of 300–923 K. The obtained values of the ZT parameter are comparable with those obtained using the induction hot pressing (IHP) technique and about 30–45% higher in the temperature range of 773–923 K in comparison with Cu2S samples densified with the spark plasma sintering (SPS) technique