Ceramics – Life Cycle Design

Zr tubes before final pilgering step
Zr tubes before final pilgering step

Ceramics are coming in of much use today in many advanced materials applications owing in part to their abundance as a resource.

As we continue to demand ever more in terms of performance from an ever increasing range of products available to us, understanding of the degrading effects and of fatigue in particular and developing solutions to them is ever taking on more significance to materials designers and engineers and in more particular in this case for ceramics.

We see Zirconium used by itself or as a cladding materials in bio implants, nuclear installation and many other ceramics like gallium are coming in good in electronics applications. Ceramics can be immensely stable and have varying mechanical, electrical, thermal and magnetic properties the reason for their increased use in advanced materials applications. Multferroic materials (many of which are transition metals or otherwise ceramics) for example exhibit immense scientific and practical usefulness because of their ability to combine several ferroic properties.

Using ceramics however requires understanding their degradation and failure processes that sometimes have to be assessed by real-time monitoring in their performance environments such as when used as a coating for thermal conductivity or as we see Zirconium alloys in Nuclear Applications.

This understanding has to build knowledge on ceramic crack initiation and propagation driving forces and failure modes under the cyclic thermal loads, harsh chemical conditions, and demanding mechanical performance. It’s therefore important to appreciate the optimum properties for the performance environment such as high temperature, mechanical loads or any other conditions that could set off creep or fatigue leading to cracking, fracture and failure.

Thermal conductivity increase and coating degradation due to sintering and phase changes are known to be detrimental to ceramics performance used in coatings for example. In these coatings exposed to thermal cycling the coating failure modes are known to be primarily coating delamination crack growth that leads to eventual buckling spallation.

There is a need to characterize the coating thermal fatigue behaviour and temperature limit, in order to potentially take full advantage of the current coating capability of the material.

We help projects with building knowledge of Fundamental Thermal Barrier Coatings materials properties including deformation, cyclic fatigue, creep and fracture and characterise them