Compressibility of Nickel

T. W. Richards gave β=0.00000043 for the average compressibility of nickel at 20° between 100 and 500 megabars press.; L. H. Adams gave β=0.00000054, and for dβ/dp, -0.0(11)4; R. F. Mehl gave β=0.000000495; and P. W. Bridgman gave β=0.000000516 up to 12,000 kgrms. press, per sq. cm. The low result obtained by T. W. Richards is attributed to the internal strains introduced by the heavy forging which was found necessary to eliminate flaws in the metal. P. W. Bridgman observed for commercial nickel rods, at 30°, δv/v₀ = -0.000000525p + 0.0₁₁21p² and, at 75°, δv/v₀ = -0.000000528p + 0.0₁₁21p²; and for drawn wire of the purified metal, at 30°, δv/v₀=-0.000000529p+0.0₁₁21p² and, at 75°, δv/v₀ = -0.000000535p+0.0₁₁21p². T. W. Richards gave 508 kilomegabars. J. P. Andrews, E. Gruneisen, S. Ratnowsky, and A. Press discussed the relation between the coeff. of thermal expansion, the at. vol., and the isothermal compressibility; and F. Bergfeld, the relations between compression and tension when the nickel is considered as a liquid of great tenacity.

R. F. Mehl gave 508 kilomegabars for the internal pressure of nickel, and 1890 kgrms. per sq. mm. for the maximum disruptive internal pressure. I. Traube, and J. H. Hildebrand and co-workers calculated relative values for the internal press, of the elements. R. von Dallwitz-Wegner gave 315,558 to 357,140 atm. for the cohesive pressure of nickel at 0°, and 212,020 to 301,948 atm. at 100°. M. Born and O. F. Bollnow calculated the cohesive force between the atoms in the space- lattice to be 3.6×10¹¹ dynes per sq. cm.