The objective of this project is to design a tool for moderate cross section reduction of
bars that are deformed within a channel slider tool that is used for equal channel angular
extrusion (ECAE). The bars that are deformed via ECAE have an initial square cross
section with a nominal value of 1.00 in2 and aspect ratios (length/width) ranging
between 4 and 6. A systems engineering design methodology is used to generate a topbottom
approach in the development of the tool's design. This includes defining a need
statement, which is the "Need for an area reduction extrusion tool to replace the current
practices of machining ECAE processed billets". The system functions and requirements
are defined next and used to generate three concepts that are compared to select the
winning concept for further refinement. Major components of the selected tool are: a
container, ram, base plate, punch plate, four die-inserts, four wedges and four flange
locks. For materials, such as copper (C10100) and aluminum (Al6061-T6), that can be
processed by this tool, the upper bound extrusion pressure, which is derived by limit
analysis, is set at 192 ksi. The upper bound extrusion pressure is constrained by the
buckling limit of the ram, which is 202 ksi. The maximum wall stress experienced by the
container is 113 ksi. For materials with the same cross section and dimensions, fixed end
conditions of the Ram support larger bucking loads when compared to other end
conditions such as rounded ends or rounded-fixed ends. With the application of the
upper bound method, an increase in the extrusion ratio of the tool causes a corresponding
rise in the optimal cone angle of the die further translating to a rise in the extrusion
pressure.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/4880 |
| Date | 25 April 2007 |
| Creators | Onipede, Bolarinwa O. |
| Contributors | HARTWIG, KARL T. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 4382017 bytes, electronic, application/pdf, born digital |
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