Abstract
Cylindrical single crystals of nickel were prepared and their thermal expansion and Young’s modulus were measured over the temperature range of 0°∼500°C by a dilatometer and by means of an electrostatic type vibrator-controlled oscillator system, respectively. Then, from the measured values, the elastic parameters Sij, Young’s modulus for three principal directions of single crystals and for a polycrystal of nickel were calculated. It has been known that there is a similar temperature dependence of Young’s moduli in the three principal directions and of Young’s modulus of a nickel polycrystal, and the calculated values of Young’s modulus for a polycrystal agree well with the measured values of the annealed polycrystal specimen. The calculated Young’s moduli at 20°C are 1.21×1012, 2.04×1012, 2.62×1012 and 1.90×1012 dyn/cm2 for the directions of ⟨100⟩, ⟨110⟩, ⟨111⟩ of the single crystals and for a polycrystal, respectively. The crystal anisotropy E⟨111⟩⁄E⟨100⟩ of the nickel single crystals at 20° and 150°C are 2.17 and 2.49, respectively.
