Аннотация:The influence of adding diamond nanoparticles on linear and non-linear elastic properties of the Al-based alloy B95 was experimentally studied. The second-order elastic constants (SOECs) in samples of the B95-alloy and the B95/nanodiamond (B95/nd) composite were determined from measurements of the densities and velocities of longitudinal and shear elastic waves. The study of nonlinear elastic properties of the B95 and B95/nd samples was conducted in two ways: third order elastic constants (TOECs) were measured by Thurston-Brugger method and the nonlinear elastic parameters were measured by spectral method. Relative comparison of the TOECs data for B95/nd composite with the data for the starting B95-alloy is made and discussed.