BERMEJO: Understanding fracture in textured layered ceramics: from macro to micro scale
Channel: Chair of Structural and Functional Ceramics
Date: 2022-06-03

[Title]
Understanding fracture in textured layered ceramics: from macro to micro scale

[Authors]
Raul BERMEJO

[Event]
97th DKG Annual Meeting - Ceramics 2022
Monday, 7th March 2022

[Abstract]
Embedding textured alumina layers has been established as a novel design strategy to enhance the fracture resistance in ceramic laminates. It has been demonstrated that tuning the location of “protective layers within a ceramic multilayer architecture can increase its fracture resistance by five times (from 3.5 to 17 MPam1/2) relative to constituent bulk ceramic layers, while retaining high strength (500 MPa). The use of tailored residual stresses in embedded layers can act as an effective barrier to the propagation of cracks from surface flaws (e.g. under bending or thermal shock loading), providing the material with a minimum design strength, below which no failure occurs. Moreover, by orienting (texturing) the grain structure, similar to the organized microstructure found in natural systems such as nacre, crack propagation can be controlled within the textured ceramic layers. In this work, the benefit of textured microstructure against contact loading will be demonstrated and compared to equiaxed microstructures. The potential of using embedded textured layers to mitigate Herztian contact damage will also be addressed. Recent findings on the fracture resistance of grain boundaries between textured grains will shed light on understanding the fracture process of textured layered ceramics, which should be explored in light of novel processing techniques such as additive manufacturing.