M. E. Fine

Low‐Temperature Internal Friction and Elasticity Effects in Vitreous Silica

Near 35°K the internal friction of vitreous silica reaches a peak value which increases with frequency. The temperature curves of the torsion and Youngs moduli are concave upward with minima near 65°K and are independent of frequency. These effects are reversible with temperature. Their cause cannot be the usual type of relaxation process or anything involving diffusion or large amounts of shear.

Elasticity and Thermal Expansion of Germanium Between −195 and 275°C

Youngs moduli (E) of the directions 〈100〉 and 〈111〉 and the shear modulus (G) for 〈100〉 were determined in germanium from −195 to 255, 275, and 140°C, respectively. From these moduli, the elastic parameters, the compressibility, and Poissonss ratio were calculated.The thermal expansion was measured from −196 to 275°C.

Elastic Constants of Germanium between 1.7° and 80°K

The elastic constants of germanium (c11, c12, and c44) increase on cooling and approach constant values for very low temperatures.

Transitions in Chromium

Discontinuous changes of Young’s modulus, internal friction, coefficient of expansion, electrical resistivity, and thermoelectric power are evidence for a transition in chromium near 37°C. Although the X-ray diffraction pattern gives no clue, a difference between the thermal expansivity and the temperature dependence of the lattice parameter suggests a crystallographic change. Young’s modulus data disclosed another transition near—152°C.

Thermal Variation of Young’s Modulus in Some Fe-Ni-Mo Alloys

Young’s modulus and its temperature coefficient were investigated in low coefficient Fe-Ni-Mo alloys under varying conditions of working and annealing. In the, ternary as well as the binary Fe-Ni alloys, the temperature interval of nearly constant Young’s modulus is greatly extended by work hardening. A stress-relief anneal is necessary to stabilize the alloys. Addition of 9 or 10 pct Mo decreases, the sensitivity of the thermal coefficient to variations in nickel by approximately a factor of two. In these, alloys the mean thermal coefficient of modulus for the temperature range —50° to 100°C varies from + 50 to —50 × l0−6 degree C−1 as the nickel varies from 36.5 to 41.5 pct. An alloy containing 9 pct Mo, 38 to 41.5 pct Ni, and balance Fe in the cold-worked condition has a low temperature coefficient of Young’s modulus, substantial magnetic permeability reasonably constant over a limited temperature range, and high strength. The coefficient of modulus can be controlled by controlling the Fe-Ni ratio. A further measure of control can be exercised by varying the straining-annealing procedure. The principal effects of molybdenum on the temperature dependence of modulus are explained by assuming that molybdenum decreases the modification in the interatomic energy-interatomic distance relation from the energy of magnetization.

Young’s modulus and its temperature dependence in 36 to 52 pct nickel-iron alloys

Young’s modulus and its temperature coefficient in 36 to 52 pct Ni-Fe alloys depend upon composition and also the straining-annealing history. Alloys near 42.5 pct Ni, when worked cold and then annealed at 400° or 600°C, have nearly zero mean thermoelastic coefficients between −50° and 100°C. A discussion of the theory is given.