Using the ultrasonic waves for studying thermal and elastic properties as a function of porosity in sintered ceramic

Abstract EN

Ultrasonic pulse echo measurements on porous alumina a،؛ ceramic material ^'؛th porosities ranging from (20-40) % showed effect of volume fraction of porosity on both thermal and elastic properties.

A quadratic relationships, by using a least squares method, is deduced for the dependence of the shear velocity, longitudinal velocity, shear modulus, Young’s modulus, bulk modulus.

Poisson’s ratio, Debye temperature, specific heat, and thermal conductivity on the total poro$ity.

By these relationships, the thermal and clastic properties results of pore-free alumina were calculated.

The elastic properties results of ceramic decrease substantially with increasing porosity, except Poisson’s ratio which is the constant.

Debye temperature and thermal conductivity ^ecrease too substantially with increase of porosity, while specific heat increases.