Mechanical properties of (U,Ce)O2 with and without Nd or Zr

The mechanical properties of (U 0.8− x Ce 0.2 M x )O 2 [M: Nd (0≤ x ≤0.13) or Zr (0≤ x ≤0.06)] were studied. The longitudinal and shear sound velocities were measured by an ultrasonic pulse–echo method at room temperature, which enabled us to evaluate the elastic properties and Debye temperature. The microhardness measurement was performed at room temperature using a micro-Vickers hardness tester. The elastic moduli such as Young’s modulus and shear modulus decrease with increasing M atoms content. The values of micro-Vickers hardness and yield stress also decrease with increasing M atoms content.