Accession Number : ADA568642


Title :   Uncovering the Physical Basis Connecting Environment and Tribological Performance of Ultrananocrystalline Diamond


Corporate Author : NATIONAL CHUNG CHENG UNIV CHIAYI (TAIWAN)


Personal Author(s) : Jeng, Yeau-Ren


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a568642.pdf


Report Date : 05 Oct 2012


Pagination or Media Count : 48


Abstract : In the first year of this project, the researchers studied the nano-scale mechanical and tribological properties of ultrananocrystalline diamond (UNCD), which is a thin-film material known to have extremely high strength and excellent tribological properties, namely low friction, adhesion, and wear, at macroscopic scales. They have successfully grown UNCD films in house and characterized their composition and structure. They measured the surface chemical properties of these samples as well as commercial UNCD samples from their collaborator, Advanced Diamond Technologies, Inc. These measurements demonstrate the expected carbon-rich composition but with measureable amounts of surface-bound contaminants. They also performed TEM observations to investigate the grain structure of commercial UNCD films, verifying a nanoscale grain size. Finally, collaborators from U. Pennsylvania visited NCCU in June 2012. They worked together on an in-situ TEM nanoindentation methodology and obtained preliminary results characterizing the adhesion and wear behavior of computational nano-scale UNCD asperities, verifying extremely low wear particularly in comparison to Si.


Descriptors :   *DIAMONDS , *GRAIN STRUCTURES(METALLURGY) , *THIN FILMS , COMPARISON , ENVIRONMENTS , FRICTION , GRAIN SIZE , HIGH STRENGTH , JOINING , MATERIALS , METHODOLOGY , MODELS , PHYSICAL PROPERTIES , SAMPLING , SIMULATION , SURFACE CHEMISTRY , SURFACE PROPERTIES , TAIWAN , TRIBOLOGY , WEAR


Subject Categories : Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE