ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The popularly accepted concept of “stress induced phase transformation (SIPT)” for tetragonal zirconia polycrystalline (TZP) ceramics has been re-evaluated in this work using an in-situ X-ray diffraction technique that was facilitated by the use of a novel stressing fixture. At stress levels of 700 MPa, which is close to the sample's rupture strength very little of the tetragonal phase transformed to a monoclinic phase, regardless of whether a tensile or compressive stress was applied. However the intensity of the peak (2 0 2)t, (2 2 0)t, (1 1 3)t, and (1 3 1)t, compared with the peak, (1 1 1)t did display a significant change after the tetragonal zirconia was loaded. In the fractured surface, a large amount of monoclinic phase was discovered. Thus we infer that for a homogenous TZP ceramic, the critical phase transformation stress is close to the material's rupture strength. On the basis of the observation of a non-linear deformation before the phase transformation, we suggest that the TZP material may have a four step response to an increasing applied stress. This response consists of; (i) anelastic behaviour which may be explained by “ferroelastic domain switching” or another anelasticity theory; (ii) t → m phase transformation; (iii) microcracks emerging and then growing; (iv) final fracture of the material and a possible reverse transformation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00356258
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