Low-cost methods for fabrication of aluminum-boron shapes

Deformation processing has not been seriously considered as applicable to composite fabrication, particularly if the filament (e.g., boron) lacks plasticity. When, however, the brittle filament is clad with a ductile matrix such as 6061 Al, the underlying filament is protected from damage even when cold worked severely as in drawing and rolling. These two metal-working processes have been applied successfully to produce seven ply aluminum 50 vol % boron tubes up to 2 in. O.D. by 3 feet in length and flats 1 in. in width by 2 feet in length respectively. Although adequate densification is achieved via drawing and rolling, the former has been given major emphasis. Mechanical properties of rolled and drawn flats and tubes compare favorably with those prepared by static methods. However, the objective of the presentation is to focus on lower processing costs. In specific terms, 2 in. tubes in lengths up to 12 feet can be produced for as little as $150/lb. This is possible only because standard drawbench and carbide dies can be utilized. Furthermore, the major steps including cladding, preform preparation and drawing are conducive to automation.