Multicomponent alloys based on Ni–Ti system known as high-temperature corrosion-resistant materials that have an attractive combination of mechanical, chemical and physical properties and are used as structural materials and functional diversification purposes. The ternary alloys of the Ni–Ti–Zr system attract attention, in particular, due to their ability to crystallize in an amorphous state at relatively low cooling rates, that is, they have the ability to form so-called bulk amorphous alloys. Literature data concern phase equilibria in the ternary system are rather limited. The system was studied in temperature interval from 700 °С to the liquidus surface in the concentration range from 0 to 50% (at.) Ni by Eremenko with co-authors (1988-1992). There is the only work in the solid / liquid equilibria region with a nickel content of more than 50 % (at.) – Liu X.J. et al (2015) – isothermal sections at 1000 and 1200 °С, that does not give an idea about crystallization processes. Besides in our previous work the solidus surface projection was constructed. In present work we present the results about the phase equilibria in the melting / crystallization region in the concentration range from 75 to 100 % (at.) Ni. The arc-melting alloys were studied by scanning electron microscopy with electron probe microanalysis (SEM / EPMA) and differential thermal analysis (DTA). Based on the results of the experimental study the liquidus surface projection and the melting diagram of the ternary one Ni–Ti–Zr system in the region Ni–Ni3Ti–Ni7Zr2 are constructed. The liquidus surface consists of four fields of primary crystallization – solid solutions of ⟨Ni⟩, ⟨Ni3Ti⟩, ⟨Ni5Zr⟩ and ⟨Ni7Zr2⟩. The liquidus temperature decreases from the bounding binary systems to the ternary one to a minimum at 1182 °С at the point Ni84.5Ti7.9Zr7.6 of the ternary eutectics composition LЕ1 ↔ ⟨Ni⟩ + ⟨Ni3Ti⟩ + ⟨Ni5Zr⟩. The invariant point coordinates on liquidus surface were established: LU1 + ⟨Ni7Zr2⟩ ↔ ⟨Ni5Zr⟩ + ⟨Ni3Ti2⟩ – Ni83.0Ti8.5Zr8.5, 1190 °С; lе3 ↔ Ni + Ni5Zr – Ni87.4Ti4.5Zr8.1, 1187 °С; lе2 ↔ Ni3Ti + Ni7Zr2 – Ni76.3Ti13.2Zr10.5, 1288 °С.

Alloys of the ternary Ni–Ti–Zr system containing 50 to 100 at.% Ni that were annealed at subsolidus temperatures were examined by scanning electron microscopy, electron microprobe analysis, and differential thermal analysis. The solidus surface was constructed in this composition range. A new ternary phase of composition Ni69.2Ti12.5Zr18.3 was found.

Alloys of the ternary Cu–Ti–Zr system with 50–100 at.% Cu, annealed at 750°C, are studied by scanning electron microscopy, electron microprobe analysis, and X-ray diffraction. The isothermal section at 750°C is constructed in this composition range. A new hexagonal ternary phase of composition Cu63.5Ti14.5Zr22 is found.

Alloys of the Ti-Si-B system in the Ti5Si3 vicinity melted in an arc furnace from pure components were studied after annealing at 1850 °C for 3 h by means of XRD analysis, scanning electron microscopy with electron probe microanalysis (SEM/WDS), and 11B solid state nuclear magnetic resonance (NMR). The phase based on Ti5Si3 (D88 crystal structure of the Mn5Si3 or Hf5CuSn3 type), Ti5Si4 silicide (Sm5Ge4 crystal structure type) and TiB2 diboride were identified in the alloys. The NMR spectra contained two well-separated narrow peaks (at δ = 9 and δ = 274 ppm; Δν = 18 and Δν = 14 kHz) related to the B atoms located in the crystal lattices of TiB2 and solid solution based on Ti5Si3 respectively, which stand out against a broad peak (δ = 150 ppm, Δν = 120 kHz) from B atoms which lack for a long-range order environment. The 11B spectra were used to determine boron contents in the constituents. The B content of the Ti5Si3-based phase determined from the integral intensity of proper narrow peaks is in agreement with SEM/WDS data (both about 5 at.%).

The effect of silicon, germanium, tin (X), and aluminum on the structure, physicochemical and mechanical properties of Ti-B-X and Ti-Al-B (5 and 7.5 at.% B) ternary and Ti-Al-B-X and Ti-Zr-Al-B (9 at.% Al and 5 at.% B; 8.5 at.% Al and 7.5 at.% B) quaternary alloys is studied by metallography, scanning electron microscopy (SEM), X-ray diffraction, differential thermal analysis (DTA), microhardness measurements, Vickers hardness measurements (from room temperature to 900°C), bending tests (room temperature), and compression tests (from room temperature to 700°C). The alloys are melted in an arc furnace from pure materials. Doping with p-elements (Al, Si, Ge, and Sn) does not change the specific titanium-boride eutectic structure in the two-phase (Ti) + TiB field. The doping additions hardly change the chemical composition of the eutectic and only decrease the boron content by 1–2 at.%. The Al, Si, Ge, and Sn (p-elements) are not soluble in TiB titanium borides and completely concentrate in the metal matrix in two-phase (Ti) + TiB alloys. The temperature of incipient sharp softening is shown to be exclusively connected with the matrix composition. It is determined that p-elements increase the hardness and strength of titanium-boride eutectic alloys in the entire temperature range of interest and increase the temperature of incipient sharp softening from 500 to 600-650°C.

Phase equilibria in the Ti-TiB2-Ti5Ge3 region of the Ti-Ge-B system are experimentally investigated at melting/solidification temperatures using x-ray diffraction, metallography, EMPA, and differential thermal analysis. The phase diagram is presented as projections of solidus and liquidus surfaces and a vertical section at 7.5 at.% B.

The structure of Ti-Nb-B alloys that are cast and annealed at subsolidus temperatures and at 1400°C is experimentally analyzed (x-ray diffraction, metallography, and electron probe microanalysis), and so are temperatures of their phase transformations (differential thermal analysis and pyrometry). No ternary phases are found in the alloys. Projections of solidus and liquidus surfaces, an isothermal section at 1400°C, and a vertical section at 7.5 at.% B are constructed. A reaction scheme is proposed for alloy crystallization.

Phase equilibria in the Ti–TiB–Ti 3 Sn region of the Ti–Sn–B system were experimentally investigated in the melting (solidification) temperature range using metallography (including EPMA), XRD, DTA, and pyrometry. The phase diagram is presented as solidus and liquidus surfaces projections and a vertical section through the 7.5 at.% B. The Sn alloying was found to have a profound hardening effect on the eutectic titanium-boride alloys.

Alloy properties and phase constitutions for ternary Ti-Al-B and Ti-B-X, quaternary Ti-10 at.% Al-B-X (where X = Si, Ge, Sn, Zr, V, or Nb) and some multi-component alloys were investigated on alloys prepared by arc melting. As cast and annealed samples were studied by metallography, electron probe microanalysis, XRD, DTA, Vickers hardness at temperatures up to 800degreesC, and compression and bend tests. Phase equilibria in the Ti-rich portions of the systems were studied in the two-phase (Ti) + (TiB) and conjugate three-phase fields. Based on the experimental data obtained, contributions of alloying additions to the mechanical properties are estimated and discussed for eutectic alloys.

The phase equilibria in the Sc–Zr–C system were investigated for the first time using metallography, differential thermal analysis (DTA), X-ray powder patterns (XRD), and electron probe microanalysis (EPMA). The projections of the solidus and liquidus surfaces were constructed. A continuous solid solution was found to form between isomorphous (NaCl-type) carbides of scandium and zirconium. As the thermodynamically most stable phase, the δ-NaCl-type phase is in equilibrium with all the phases that exist at subsolidus temperatures. The microhardness of this phase at the carbon-rich boundary of the homogeneity range decreases monotonously from 2970kgmm−2 for ZrC1−x to 1100kgmm−2 for ScC1−x. There are two four-phase incongruent-type equilibria with participation of the liquid phase: L+δ+β-Sc4C3⇄Sc3C4 (1810°C) and L+δ⇄Sc3C4+C (1737°C).

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Rare-earth (RE) elements, known as “industrial vitamins”, have permeated modern lives, especially in high-tech applications. Although the RE elements possess close chemical similarities and have been treated as “one element” in the periodic table, their characteristics differ from each other. The RE micro-alloying effect is the crux to ameliorate the physicomechanical and thermochemical properties of materials, thereby the study of RE-related phase diagrams becomes indispensable to the design and optimization of RE-containing materials. However, in reality, the knowledge base in this area is considerably scarce compared with that of other commonly-used elements. In this work, the phase equilibria, phase diagrams, phase transformations, and some recent examples of RE-containing materials design are summarized, with which one can predict the RE solubilities, the RE precipitates, as well as the corresponding service behaviors. The attainment of enhanced materials’ properties suggests that the thermodynamic rules extracted from the phase diagrams could serve as fundamental criteria for the successful development of novel RE-containing materials.

We have investigated alloys in the Cr-Mo-Ti-C, Cr-Re-Ti-C, and Cr-Mo-Re-Ti-C systems in the eutectic + crystallization region. We found a four component quasibinary eutectic + with 4–8 at. % molybdenum content with melting point 1630°C. Additions of 3–11 at. % Mo or 5–20 at. % Re to the base eutectic alloy Cr 79 Ti 12 C 9 doubles the Vickers hardness at 1000°C (to approximately 2000 MPa), and simultaneous introduction of molybdenum and rhenium (the alloy Cr 51 Mo 8 Re 20 Ti 12 C 9 ) raises the hardness to 3000–3500 MPa.

Phase equilibria in the ternary system Sc−Cr−C were investigated by metallography, differential thermal analysis, x-ray diffraction, and electron probe microanalysis. A projection of the solidus surface was constructed for the first time. The nature of phase equilibria in the system is defined by the presence of two thermodynamically stable phases based on the compounds Sc2CrC3 (whose existence was confirmed) and ScC1−x. The melting point of the alloys increases with increasing carbon concentration. Compositions in the 〈Cr〉+〈ScC1−x〉+〈Sc〉 range have a minimum melting temperature equal to 1018±2°C, and the maximum melting temperature in the system, 1660±2°C, is found in alloys containing 〈Cr3C2〉+〈Sc2CrC3〉+C.

The phase diagram constitution of the Sc-Ti-C (scandium-titanium-carbon) system was investigated for the first time by metallography, differential thermal analysis (DTA), x-ray powder patterns (XRD), and electron probe microanalysis (EPMA). The projections of solidus and liquidus surfaces were constructed. Continuous series of solid solutions based on isomorphous (NaCl-type) carbides of scandium and titanium were found to form. As the most thermodynamically stable phase, this phase is in equilibrium with all phases of the solidus surface: Sc15C19, βSc4C3 β(Sc, Ti), and graphite. There are two four-phase incongruent-type equilibria with the participation of the liquid phase.

Chemischer InformationsdienstVolume 5, Issue 42 Preparative Inorganic Chemistry ChemInform Abstract: STABILISIERUNG DES HOECHSTEN MOLYBDAENCARBIDS DURCH UEBERGANGSMETALLE DER IV.-VI. GRUPPE DES PERIODENSYSTEMS V. N. EREMENKO, V. N. EREMENKOSearch for more papers by this authorT. YA. VELIKANOVA, T. YA. VELIKANOVASearch for more papers by this authorL. V. ARTYUKH, L. V. ARTYUKHSearch for more papers by this authorS. V. SJABANOVA, S. V. SJABANOVASearch for more papers by this author V. N. EREMENKO, V. N. EREMENKOSearch for more papers by this authorT. YA. VELIKANOVA, T. YA. VELIKANOVASearch for more papers by this authorL. V. ARTYUKH, L. V. ARTYUKHSearch for more papers by this authorS. V. SJABANOVA, S. V. SJABANOVASearch for more papers by this author First published: October 22, 1974 https://doi.org/10.1002/chin.197442056Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume5, Issue42October 22, 1974 RelatedInformation

On the basis of literature data, the conclusion is reached that all W-MeIV,V-C systems can be expected to exhibit continuous intersolubility of carbides with the NaCl structure.