Seminar 3/30/2011 - Prof. Sanjay Sampath, Stony Brook University: On the bio-mimetic response of plasma sprayed ceramics
Professor Sanjay Sampath
Center for Thermal Spray Research Materials Science and Engineering
Stony Brook University
Layered, brick and mortar-structures observed in natural systems such as Nacre (mother of pearl) have been a subject to intense research enquiry due to their novel mechanical properties, most importantly a combination of strength and toughness. These properties are attributed to both the microstructural architecture (brick and mortar) and the constituent elements (organic-inorganic hybrid composites). It has long been appreciated that inorganic layered materials produced by successive impact of molten droplets via plasma spray inherently generate a "brick-wall" microstructure. The spray formed deposits created by assembly of micron-sized molten particles/splats in many ways can be considered synthetic analogues of nacre, at least upon visual inspection.
Recent studies have shown that plasma sprayed ceramics also display similarities in mechanical properties as that of Nacre, including non-linear elasticity, anelasticity and some elements of enhanced toughening. Noteworthy is that these novel properties are seen even in the absence of any organic matter at the interfaces. As with natural systems, there is anecdotal evidence that these characteristics may impart strain tolerance in thermo-structural coatings (e.g., thermal barrier coatings) and the properties are tunable via process and material manipulation. Furthermore, the plasma sprayed layered ceramic coatings also serve as templates for synthesis of organic-inorganic hybrid composites similar to nacre. That is to say, there is potential for the incorporation of organic material between the micron-scale "bricks" for further enhancement of mechanical behavior.
This presentation will discuss recent observations on the deformation behavior of plasma sprayed ceramics and highlight their similarities with modeled predictions for nacre. Preliminary results on the synthesis of biomimetic nacre like composites that incorporate organic material will also be presented.
Location: Bowen Hall Atrium
Date/Time: 03/30/11 at 12:00 pm - 03/30/11 at 1:00 pm
Category: PRISM/PCCM Seminar Series