Explosive compaction and low-temperature sintering of alumina nanopowders

Abstract

Physical aspects of explosive compaction of alumina nanopowders with different phase compositions are studied experimentally. Physical processes that occur during consolidation of nanoparticles under pulsed loading are considered. Conditions of retaining of the material nanostructure after compaction and subsequent low-temperature sintering are determined. Physicomechanical properties of explosive compacts and ceramics on the basis of these compacts are studied. A ceramic material characterized by a nanostructure (grain size of ≈200 nm) and high values of density (97% of the theoretical value) and microhardness (up to 23.5 GPa) is obtained.

Characterization of fine-grained W–10wt.% Cu composite fabricated by hot-shock consolidation

“…Due to the rapid cooling rates of 10 9 K/s, the melting of particle is limited to the surface while the interior of particle remains relatively cool [17,18]. These inherent properties make the SC method suitable for consolidation of metastable powders, such as nano-sized and amorphous powders, where the consolidated bulks can retain its initial particle size with a density nearly full [19,20]. However, in the case of brittle materials, such as ceramic and refractory powders, it is difficult to achieve full density due to the cracks generated by tensile stresses and thermal residual stresses under the rapid cooling rate.…”

Development of the Process of Pseudo-Ligatures Manufacturing from Aluminum and Nickel Powders for the Modification of Alloys

“…When the compacting pressure increases, the density of briquettes and the degree of deformation of the powder particles also increase. [12]. Subsequent heating leads to tension relaxation due to prerecrystallization and recrystallization processes.…”