| ABSTRACT: | ULTRASONIC VELOCITY MEASUREMENTS IN ALUMINA-ZIRCONIA CERAMIC
COMPOSITE SYSTEM
H. Carreon, J. Zarate, and G. Barrera
Instituto de Investigaciones Metalurgicas, Edif. "U" Ciudad Universitaria, Morelia, Mexico
Among new structural materials, composites are attractive because they combine the properties of two o
more materials. As an important example, in alumina-zirconia ceramic composite system, the incorporation
of ‡-Al2O3 into stabilized zirconia increased significantly the mechanical and thermal properties. In this
work an alumina-zirconia ceramic composite have been prepared with different ‡-Al2O3 contents from 10
to 95 wt% in order to investigate the enhancement in mechanical properties of this composite. The different
composition were monitored by precise ultrasonic velocity measurements. In order to find out the factors
affecting the variation in wave velocity, the ceramic composite have been characterized by X-ray
diffraction measurements and scanning electron microscopy. It was found that the ultrasound velocity
changed considerably with respect to the ceramic composite composition. Mainly, we studied the behavior
of the physical material property hardness, an important parameter of the ceramic composite mechanical
properties, with respect to the variation in the longitudinal and shear wave velocities. Shear wave velocities
exhibited a stronger interaction with microstructural and sub-structural features as compared to that of
longitudinal waves. In particular, this phenomema was observed for the highest ‡-Al2O3 content composite.
Interestingly, an excellent correlation between ultrasonic velocity measurements and ceramic composites
hardness was observed.
|