Several Techniques for One-Dimensional Strain Shock Consolidation of Multiple Samples

Abstract

We explored three methods of shock wave powder consolidation which retain the one-dimensional nature of a plane shock wave and allow multiple samples to be consolidated. The first technique uses a porous sintered metal cylinder as a shock fixture. The sintered material is chosen to match as closely as possible the solid density and compressibility of the powder to be investigated. The second method does not require a compatible porous material. A cylindrical target cavity is separated into multiple regions by thin sheet metal dividers. The dividers are of the same scale thickness as the powder size to retain a one dimensional condition in most of the compact. The third method may be the most interesting technologically. A powder media of near impedance match to the material under study is selected which resists bonding under the shock conditions to be used. Pressed greens of the material to be consolidated are then embedded in this pressure -transmitting media. The greens are then shocked along with the 'non-stick' media. In our experiment, a discontinuously reinforced metal matrix composite (MMC) was shock consolidated to near net shape by this method. Ti powder was mixed with SiC powder, pressed into a green with corners and radii, and embedded in fine zirconia powder. The shock wave generated by a 304 stainless steel flyer plate accelerated to 1.0 km/ s fully consolidated the MMC without bonding the zirconia. The compact was recovered with well defined corners and flat surfaces.