Plastic Deformation in Alumina by Explosive Shock Loading

Spherical alumina powder, composed of α-Al₂O₃ and transitional alumina phases, was compacted by explosive shock loading with maximum pressures of 13 to 26 GPa and a maximum adiabatic temperature rise of ∼400°C. A final density >90% of theoretical was achieved. The powder densified primarily by plastic deformation, with only occasional particle fracture. Transmission electron microscopy showed dislocation densities of at least 10¹¹ cm⁻² in all phases and extensive twinning in transitional alumina phases.