L. V. Artyukh

Titanium-Boride Eutectic Materials: Phase Equilibria and Constitution of Alloys in the Ti-rich Portion of the Ti-V-B System

Phase equilibria and constitution of alloys were experimentally investigated in the Ti-TiB-(Ti_o 5V_o 5)BTi_4oV-6o region using metallography (optical microscopy and SEM/EPMA), differential thermal analysis (DTA), and X-ray diffraction (XRD). The phase diagram in the • melting (solidification) temperature range has been constructed as solidus and liquidus surfaces projections and a vertical section at 9 at.% B. The V alloying was found to decrease melting temperatures from 1500 °C for the binary (Ti) + TiB eutectic to 1430 °C for the ternary invariant equilibrium Le <-» (Tio.63Vo.37) + (Ti0.74V0 26)B and then to increase them. At that, the composition of (ßTi,V) + (Ti,V)B monovariant eutectic becomes richer in boron, from 7.07.5 at.% Β in the Ti-B binary to about 8.5 at.% Β at 40 at.% V. The V contents in metal and boride phases after partition are comparable. Vanadium sharply decreases the α <-> β transition temperature, so that at ~10 to -15 at.% V as-cast arc melted alloys are multiphase and at -20 at.% V practically completed ß-stabilization is observed.

New high-temperature heat-resistant alloys on the basis of the Cr–Ti–C system

Abstract The outlook is good for the structure and mechanical properties of eutectic alloy Cr–Ti–C in the temperature range from 200 to 1200°C as high-temperature material has shown. The possibilities of increasing high-temperature strength of Cr–Ti–C alloy by alloying with iron, scandium, lanthanum, molybdenum, and rhenium are discussed.

Phase equilibria in the ternary system Sc−Cr−C at subsolidus temperatures

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.

Structure and properties of multicomponent eutectic alloys based on chromium and titanium carbide

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 Cr79Ti12C9 doubles the Vickers hardness at 1000°C (to approximately 2000 MPa), and simultaneous introduction of molybdenum and rhenium (the alloy Cr51Mo8Re20Ti12C9) raises the hardness to 3000–3500 MPa.

Phase Equilibria in the Cu–Ti–Zr System at 750°C. II. The Isothermal Section with Copper Content from 50 to 100 at.%

Optical and scanning electron microscopy, electron microprobe analysis, and X-ray diffraction are employed to examine alloys in the Cu–Ti–Zr ternary system, annealed at 750°C, with copper content from 0 to 50 at.%. A partial isothermal section of the phase diagram is constructed at 750°C in the composition range in question. The existence of a continuous series of solid solutions between CuTi2 and CuZr2 isostructural compounds (γ phase, MoSi2 type) is confirmed. The homogeneity ranges of Cu2TiZr ternary compound (τ1, MgZn2 type) and β-(Ti, Zr), (CuTi) (CuTi type), and CuZr (CsCl type) solid solutions are determined.

Continuous series of solid solutions of carbides with the NaCl structure in the ternary systems Mo(W)-MeIV, V-C

Conclusions1.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.2.Experimental evidence in support of this contention was obtained in a study of the structures, produced by quenching from subsolidus temperatures, of ternary alloys containing Ti, Zr, Hf, and V, which had not been investigated before (at these temperatures).