Resintering behavior of alumina compact on the route of controlled fracture forming

The resintering behavior of swaged Al₂O₃ up to 98% reduction in area was investigated to discuss the intense cold-working effect in the green state. The relative density of resintered Al₂O₃ could be improved to be close to 99% theoretical density at 1573 K for 1 h, and negligibly small grain growth was observed when the relative density became less than 97.5%. Grain boundary diffusion was considered to be a dominant mechanism for resintering the swaged Al₂O₃ by calculating the activation energy. The negligibly small grain growth was attributed to the homogeneous microstructure in the green state attained by the controlled fracture forming.