Advanced Materials Processing
This invention can be used to produce relatively low cost advanced materials with superior properties.
University researchers have developed a method called In Situ Variable Equal Channel Angular Pressing (VECAP) - a system and method for producing ultra-fine grain and nanocrystalline materials with a desired gradient in microstructure. Conventional ECAP has involved the use of an extrusion die with a fixed angle that is typically in the range of 140 to 90 degrees. The present invention involves a die system in which this angle is varied during the extrusion process and possibly between extrusion passes. The major benefits are: (1) unique ability to produce materials with extremely low porosity at relatively low temperatures with a gradient in grain size that can fall within nanoscale dimensions; (2) unique ability to initiate the ECAP process at relatively low ram stress using a high die angle and then continuing the extrusion with a desired lower angle; and (3) rapid adjustment of the die angle between extrusion passes without the need for and cost of fabricating a different die for each potentially useful die angle.
Tech ID/UC Case 18800/2006-055-0 Related Cases 2006-055-0
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