All alloys of the type of $\beta$-brass decrease their concentration range in the disordered state as the temperature is lowered. The original theory of Jones is shown to be inadequate, and the observed variation with temperature of the phase boundaries is shown to follow directly from the assumption that the $\beta$-phase has a slightly lower characteristic temperature than the neighboring phases.

Beta-brass has an extremely high elastic anisotropy. This property is in part a result of an anomalously low value of $\frac{(C_{11}-C_{12})}{2}$, which is shown to be interpretable in terms of lattice type and inter-ionic interactions. This interpretation also explains the positive value of the temperature coefficient of $E_{100}$.

• Received 6 March 1947

DOI:https://doi.org/10.1103/PhysRev.71.846