Shock consolidation: Microstructurally-based analysis and computational modeling

Journal Article · Fri May 28 04:00:00 EDT 1999 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00083-X· OSTI ID:357927

Meyers, M A; Benson, D J ^[1]; Olevsky, E A ^[2]

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1. Univ. of California, San Diego, La Jolla, CA (United States). Dept. of Applied Mechanics and Engineering Sciences
2. San Diego State Univ., CA (United States). Dept. of Mechanical Engineering

The most important microstructural processes involved in shock consolidations are identified and discussed; the energy dissipated by a shock wave as it traverses a powder is assessed. The basic microstructural phenomena are illustrated for a metal (nickel-based superalloy), an intermetallic compound (rapidly solidified Ti{sub 3}Al), and ceramics (silicon carbide). Interparticle melting, vorticity, voids, and particle fracture are observed and the plastic deformation patterns are identified. Various energy dissipation processes are estimated: plastic deformation, interparticle friction, microkinetic energy, and defect generation. An analytical expression is developed for the energy requirement to shock consolidate a powder as a function of strength, size, porosity, and temperature, based on a prescribed interparticle melting layer. This formulation enables the prediction of pressures required to shock consolidate materials; results of calculations for the superalloy and silicon carbide as a function of particle size and porosity are represented. The fracture of ceramic particles under shock compression is discussed. Tensile stresses are generated during compaction that may lead to fracture. It is shown that the activation of flaws occurs at tensile reflected pulses that are a decreasing fraction of the compressive pulse, as the powder strength increases. These analytical results are compared to numerical solutions obtained by modeling the compaction of a discrete set of particles with an Eulerian finite element program. These results confirm the increasing difficulty encountered in shock consolidating harder materials, and point out three possible solutions: (a) reduction of initial particle size; (b) reduction of shock energy; (c) post-shock thermal treatment.

• OSTI ID: 357927
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 7 Vol. 47; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPACTING
ENERGY LOSSES
FRACTURES
MATERIALS
MATHEMATICAL MODELS
MELTING
MICROSTRUCTURE
POWDERS
SHOCK WAVES
VOIDS