 |
Tuesday, December 4, 2007 - 10:00 AM
Site Directed Nucleation and Growth of Ceramic Films on Metallic Surfaces:
Ceramic coating systems require multiple layers of toxic components, or involve deposition and application processes that are hazardous or require high temperatures. The development of a ceramic coating system that mimics a naturally occurring biomineralization process, where deposition of the ceramic material can be controlled under ambient conditions and is environmentally friendly, is quite attractive. The first step in developing this new type of system is to understand how the deposition and biomineralization process occurs in a working biological model. In this case, the model is the Eastern oyster (Crassostrea virginica), and the process is the formation of its calcified outer shell. The different types of oyster cells that are involved and the conditions under which those cells adhere and deposit crystals onto aluminum alloys Al2024 and Al7075, the titanium alloy Ti6Al4V and 316L stainless steel has been studied and characterized. This has been achieved by allowing the hemocyte cells to adhere and deposit crystals onto the metal substrate. In addition to characterizing the conditions necessary for the adhesion and deposition of individual crystals, the oyster model system has been successfully manipulated to allow the deposition of multiple crystals which coat the metal substrate with the ceramic material. Standard methods for microscopic studies of the oysters’ cellular biomineralization and crystalline layer formation mechanisms have been established, yielding evidence that the cellular response is metal-substrate dependent, different types of hemocyte cells are involved in the deposition of crystals, and that deposition occurred on all of the substrates tested.
See more of AFOSR Review I
See more of The 2007 Tri-Service Corrosion Conference (December 3-7, 2007)
See more of The 2007 Tri-Service Corrosion Conference (December 3-7, 2007)