Insights into microstructural formation of pulse plasma semisolid to liquid processing of Al ₂ O ₃ –ZrO ₂ eutectic ceramics

Abstract

Abstract This present work concentrated on a novel one‐step pulse discharge plasma melting method, directly from a powder mixture of nano‐sized Al 2 O 3 –ZrO 2 (Y 2 O 3 ) to in situ fabricate Al 2 O 3 –ZrO 2 binary eutectic in a short processing time. A continuous transition from submicro‐sized polycrystalline to non‐equilibrium eutectic was traced based on pulse discharge plasma semisolid to liquid processing. The uniform colony microstructure with an average inter‐lamellar or inter‐rod spacing of ~200 nm was obtained at a growth rate of ~275 μm/s, and the inter‐lamellar or inter‐rod spacing was a good fit for the inverse‐square‐root dependence of the growth rate as λ a = 3.32 × v −1/2 .