Room temperature mechanical properties of polycrystalline YbAl3, a promising low temperature thermoelectric material

► Room temperature Young's, shear, bulk moduli, Poisson's ratio measured for YbAl3. ► Volume fraction porosities, P, from 0.030 < P < 0.233, polycrystalline YbAl3. ► P dependence of properties similar for specimens densified by hot pressing, PECS. ► Fracture toughness from 1.1 to 1.6 MPa m1/2, hardness 6.81 GPa (P = 0.030). ► Intermediate valence of Yb ion may make theoretical modulus calculations difficult.