Peculiar elastic behavior of Ti–Nb–Ta–Zr single crystals

The single-crystal elastic moduli Cij and their pressure derivatives dCij/dP have been measured ultrasonically at 25 degrees C for six Ti-V-Cr, eight Nb-Mo and seven Ta-W solid solutions. The rigid-band model for the alloy electronic structure is known to work fairly well for these BCC metals in predicting the density of states at the Fermi energy and related properties. The results of this study show that changes in the composition dependence of the Cij and dCij/dP appear to be related to specific topological changes in the Fermi surface which occur as the electron population varies in the rigid-band model. The relationship between the bandstructure and the Cij is discussed and a qualitative explanation is given for the correlations between the moduli and the Fermi surface and for some of the differences between the three alloy series.

https://iopscience.iop.org/article/10.1088/0305-4608/9/5/006/pdf

Pressure derivatives of the elastic moduli of BCC Ti-V-Cr, Nb-Mo and Ta-W alloys

Elasticity effects on the microstructure of alloys containing coherent precipitates

Solid-solution strengthening in refractory high entropy alloys

The single-crystal elastic moduli of chromium have been measured ultrasonically to 5 kbar and from 80 to 700K. In the paramagnetic phase the shear moduli are found to be approximately linear functions of pressure and temperature for pressures and temperatures above the Neel transition line. At atmospheric pressure, the compressional modulus C11 increases with temperature above TN up to a maximum at about 475K, and then decreases and becomes a linear function of T above 550K.C11 is not a linear function P for temperatures up to 473K. The results for paramagnetic chromium are combined with previous results on Ti-V and V-Cr alloys to discuss the relationship of the elastic properties to the electronic bandstructure of these alloys.

http://iopscience.iop.org/article/10.1088/0305-4608/9/11/008/pdf

Elastic moduli of paramagnetic chromium and Ti-V-Cr alloys

The adiabatic elastic constants have been determined for quenched single crystals of niobium‐zirconium alloys of the following nominal compositions: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 70 at.% Zr. The c11, c12, and c44 constants as well as the shear constant C′= (1/2) (c11−c12) and the bulk modulus are given between 4.2 and 300 K. We observe for the whole range of compositions an anomalous temperature behavior for c44 similar to that found in pure Nb, but here the amplitude of the effect disappears progressively with increasing Zr concentration. The Debye temperatures were computed from the constants at 4.2 K.

M. Peter

Papers

Elastic constants of the bcc phase in niobium-zirconium alloys between 4.2 and 300 K