Alumina–Nickel Composite Processed via Co‐Assembly Using Freeze‐Casting and Spark Plasma Sintering

Abstract

A metal–ceramic composite comprised of ≈82 vol% alumina (Al 2 O 3 ) and ≈18 vol% nickel (Ni) is fabricated via co‐assembly of alumina micro‐platelets with Ni particles using the freeze‐casting process followed by the spark plasma sintering (SPS). The SPS processing with a custom‐designed temperature‐pressure history result in formation of elongated Ni phase between the lamellar‐ceramic phase. Results of the mechanical characterization shows that inclusion of Ni improves the flexural strength of the composite by more than 47% compared to the lamellar ceramic. Additionally, the crack initiation (K IC ) and crack growth toughness increase by 20% and 47%, respectively. The inclusion of softer Ni phase does not compromise the indentation modulus and indentation hardness of the composite compared to the pure ceramic.