Influence of structural macrodefects of alumina on nonlinearity of resonant mechanic oscillations

Abstract

Nonlinear elastic behavior of porous alumina containing from 4 to 16% (vol.) polyethylene glycol binder sintered at 1623 to 1848 К under condition of mechanical resonance with aim to estimate of presence of crack-like structural macrodefects is studied. The dependences of Young's modulus and nonlinearity parameter C_N that characterized influence of amplitude of oscillations on their resonant frequency, on porosity were studied. The presence of crack-like defects, in addition to porosity and pore shape, was found to be a factor of influence on Young's modulus value. The correlation between crack density and nonlinearity parameter C_N was found while no definite relation was observed between C_N and porosity.