Elasticity Constants of Single Crystals of Nickel-Copper Alloys

Single crystals of Ni-Cu alloys were prepared by the Bridgman method of slow solidification, and Young\u27s moduli were measured at room temperature by a new microscopic method. From the measured values, Young\u27s moduli for the principal orientations were derived. Young\u27s modulus in[100]direction decreases at first with the addition of copper to nickel, reaches the minimum at about 10, the maximum at about 25 per cent copper, and then decreases with further increasing content of copper. The behavior of Young\u27s modulus in[110]direction is similar to that of E_, while in[111]direction it decreases monotonously. The three principal elastic coefficients S_, S_ and S_ were determined by using the data of compressibility for polycrystals of Ni, Cu and a Ni-Cu alloy containing 45 per cent of copper. Futhermore, the principal rigidity moduli were derived