V. G. Khoruzhaya

Solidus surface of the Ti-Ru-Ir system

ConclusionsThe interaction of the components in the Ti-Ru-Ir system at the subsolidus temperatures was examined. Intermediate phases differing from those existing in the limiting binary systems were not detected. The equiatomic phases TiRu and TiIr which are isostructural at high temperatures form a continuous series of the solid solutions. The solubility of ruthenium in TiIr3 reaches 27%, and in Ti3Ir ruthenium does not dissolve. The solidus surface of the system contains three isothermal planes whose temperatures (2220, 1920, 1465‡C) decrease with increasing ruthenium and titanium content of the alloys. The lowest solidus temperature of the Ti-Ru-Ir system is the melting point of the 〈Β-Ti〉 + Ti3Ir binary eutectic of the Ti-Ir system (1460‡C).

The structure of alloys and the phase equilibrium diagram of the Zr-Ru-Ir system. V. Plan of crystallization of alloys of the Zr-ZrRu-ZrIr partial system

This paper presents a plan of the reactions occurring in crystallization of alloys of the Zr-ZrRu-ZrIR partial system and the phase composition and structural constituents of as-cast alloys of the system. A correct and full confirmation of the certainty of the phase equilibria established in the Zr-ZrRu-ZrIR system was the result of differential thermal analysis made on specimens selected from the most complex areas of crystallization of the alloys and annealed at 1000 C after preliminary homogenization of them at higher temperatures.

Structure of the alloys and the phase equilibrium diagram of the Zr-Ru-Ir system. IV. The projection of the solidus surface of the partial system Zr-ZrRu-ZrIr

The results of an investigation of the solidus surface of the second partial system of the ternary Zr-Ru-Ir-Zr-ZrRu-ZrIr system are presented. In the Zr-Ir system there exist four intermediate phases. For investigating the phase equilibria in the Zr-ZrRu-ZrIr system, alloys of 36 compositions were prepared by arc melting in argon. Under arc melting conditions, the majority of the alloys crystallized in a very nonequlibrium condition, as the result of which in the latter stage of the process they contained a relatively low-melting constituent. The alloys were investigated in the cast and annealed conditions by metallographic, hardness, x-ray diffraction, local x-ray spectral, and differential analyses. Temperature of the start of melting was determined by the Pirani-Altertum method. Illustrations show the isothermal section of the Zr-ZrRu-ZrIr system. In accordance with the solidus temperatures only four of the alloys investigated are found in the solid state while at 1200/sup 0/C only the alloys lying close to the isothermal plane of the solidus surface at 1175/sup 0/C remain in the liquid state.

Structure of alloys and diagram of phase equilibria of the Zr-Ru-Ir System. III. Isothermal sections of the Ru-ZrRu-ZrIr-Ir system

The authors take data from an investigation of alloys annealed successively at temperatures of 1900 and 1600 degrees C for 10117 h and use them to construct isothermal sections of the RuZrRu-ZrIr-Ir system. They conclude that in the ternary system the iridium addition will stabilize the lambda, phase and a change of phase equilibria linked with its decomposition will occur at temperatures below 1285 degrees C.

Structure of alloys and diagram of phase equilibria of the Zr-Ru-Ir system. II. Solidification pattern of alloys of the partial system Ru-ZrRu-ZrIr-Ir

The authors constructed the solidification diagram of alloys of the partial system Ru-ZrRu-ZrIr-Ir using data on the structure of alloys in the as-cast condition, yielded from metallographic examinations, microhardness determinations, and x-ray phase analyses together with results of an investigation of the solidus surface of the system. No ternary compounds were detected in the system. In accordance with the four three-phase regions found on the solidus surface, in the Ru-ZrRu-ZrIr-Ir system there are four invariant equilibria involving the participation of liquid, each of which is an equilibrium of the peritectic type. Their temperatures fall toward the Zr-Ru side of the composition triangle.