An in-situ investigation on the critical phase transformation stress of tetragonal zirconia polycrystalline ceramics
An in-situ investigation on the critical phase transformation stress of tetragonal zirconia polycrystalline ceramics
复制标题
四方氧化锆多晶陶瓷临界相变应力的原位研究
DOI：
10.1007/bf00356258
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发表时间：
1996
影响因子：
4.5
通讯作者：
S. Horibe
中科院分区：
文献类型：
--
作者：
L. Pan;S. Horibe
这项工作使用原位 X 射线衍射技术重新评估了普遍接受的四方氧化锆多晶 (TZP) 陶瓷的“应力诱导相变 (SIPT)”概念，该技术通过使用新型应力夹具来促进。在接近样品断裂强度的 700 MPa 应力水平下，无论施加拉伸应力还是压缩应力，几乎没有四方相转变为单斜相。然而，负载四方氧化锆后，(2 0 2)t、(2 2 0)t、(1 1 3)t 和(1 3 1)t 峰的强度与(1 1 1)t 峰相比确实显示出显着变化。在断口中发现了大量的单斜晶相。因此我们推断，对于均质 TZP 陶瓷，临界相变应力接近材料的断裂强度。根据相变前非线性变形的观察，我们认为 TZP 材料可能对增加的外加应力有四步响应。该响应包括： (i) 滞弹性行为，可以用“铁弹性域切换”或其他滞弹性理论来解释； (ii)t→相变； (iii) 微裂纹出现并随后扩大； (iv) 材料的最终断裂和可能的逆转变。
The popularly accepted concept of “stress induced phase transformation (SIPT)” for tetragonal zirconia polycrystalline (TZP) ceramics has been re-evaluated in this work using anin-situX-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)tdid 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→mphase transformation; (iii) microcracks emerging and then growing; (iv) final fracture of the material and a possible reverse transformation.