The Au–Pb system has been redetermined using dta, metallography and X-ray techniques. The compounds Au2 Pb, AuPb2 and AuPb3 are generated by peritectic reactions at 434° , 253° and 221.5°C respectively. AuPb3 and Pb form a eutectic at 84.8 at% Pb and 212°C. It is confirmed that Au2 Pb is stable down to at least 200°C.

The In–Sn system has been redetermined using dta, metallography and X-ray diffraction techniques. It is confirmed that the B and y intermediate 8hases are formed by peritectic reactions, at 141.0° and 222.6°C respectively. β and γ form a eutectic at 47.4 at% Sn and 119°C. The kink in the γ–phase solidus proposed by Heumann and Alpaut is not confirmed.

Alloys from the Ni–rich corner of the Ni–Al–Zr system have potential for use in high temperature, high strength applications. Such applications require a detailed knowledge of the high temperature phase equilibria.

In the case of the Ni–Al–Zr system no isothermal sections have been published although the existence of a monovariant eutectic valley between Ni3Al and Ni7Zr2 has been established. An experimental determination of the phase equilibria in this system is being carried out using quantitative electron microprobe analysis (JEOL JSM–U3), xray diffraction and optical metallography. Partial isothermal sections are being determined for 1373K (1100°C) and 1273K (1000°C) and the resulting phase equilibria compared to that in the Ni–Al–Hf system determined previously.

In a recent review of the published literature on this system it was concluded that there is a lack of experimental data in this system particularly in regions of the system with less than 75 atomic per cent of each one of the components (1). In order to provide some consistent data over a substantial range of composition an experimental determination of the phase equilibria at 1173K and from 0–50 atomic % Al is being carried out. The main experimental technique being used is quantitative electron microprobe analysis (JEOL 733) by wavelength dispersive x-ray spectrometry. In addition, x-ray diffraction is being used to establish the structures of phases present and optical metallography of cast structures to determine the fields of primary crystallization. In addition to establishing the phase equilibria at this temperature the composition range for the existence of the AlNi2Ti phase is being determined. The results thus far are compared with previous experimental data and calculated isothermal sections (2).

A portion of the Cu-Pb-Sn ternary diagram was determined experimentally. The investigation was concentrated on the high Pb corner and, to a lesser extent of alloys from Sn to the binary Pb-Sn eutectic. The experimental techniques used were thermal analysis, metallography, and electron microprobe analysis. A new technique for determining liquidus temperatures was used. For the high Pb region the proposed ternary eutectic at 0.06 Cu 0.02% SnPb (all compositions are in weight %) was not observed. For most alloys the primary crystallization phase was Cu3Sn. It was shown that Cu6Sn5 exists in the solid state; for high Sn alloys, it was observed that the addition of Pb reduced the decomposition temperature of Cu6Sn5. A ternary eutectic reaction near the binary Pb-Sn eutectic was confirmed, and the temperature of the ternary eutectic was 1°K below that of the binary eutectic. Liquidus temperatures as well as other reactions detected by thermal analysis will be presented.

It is well known that the morphology of primary and eutectic silicon resulting from solidification is sensitive to minor impurity additions: “modification” by alkali and alkaline earth metals is common foundry practice and the use of strontium is of recent and current interest because its effect is retained in liquid metal for relatively long times. The mechanism for modification remains obscure and is not necessarily the same from one elemental addition to the next, but it is essential to separate the equilibrium and kinetic influences if the phenomenon is to be better understood. Accordingly, the liquidus surface and eutectic reactions have been located in the relevant part of the Al-Si-Sr system by careful thermal analysis and the results correlated with the microstructure. Comparison is made with the parallel behavior of alkali metal additions.

The microstructure of alloys undergoing a monotectic reaction, Liquid I ⇆ Solid I + Liquid II, is related to the height of the liquid miscibility gap, upper consolute temperature, TC, relative to that of the monotectic horizontal at TM. It has been shown in the system Cu-Pb-Al that a transition in microstructure occurs as the temperature interval, Tc-TM, changes with composition. In order to observe the structural change directly in a transparent material, it has been necessary to determine the liquidus surface for the system succinnonitrile(S)-ethanol(E)-glycerol(G). In this system monotectic reactions in the binary S-E and S-G systems are joined by a monovariant valley and a structural transition occurs at approximately 85.6 wt. % S, 7.5 wt. % E, 6.9 wt. % G, at a ratio of 48:52 = G:E.

The six T5-Tl0 metal alloy phase diagrams containing Pd or Pt have now all been established. The alloy phases occurring in these systems are tabulated and reviewed here with respect to their structures.

PHAB is intended to be a complete bibliographic file of the phase diagram data papers pertaining to the experimental determination, evaluation and calculation of phase diagrams of binary, ternary and higher-order alloy systems. Metastable as well as stable equilibrium data, crystal structure, thermodynamic and high pressure data are included. The database will provide a service to the scientific community as well as serving the ASM/NBS Data Program for Alloy Phase Diagrams. The PHAB Database will serve as a source of data to the other activities and outputs of the Program, including alloy system evaluations, the Bulletin of Alloy Phase Diagrams and bound volumes of evaluated phase diagrams. as well as other databases.