The toughening of alumina with nickel inclusions

TLDR: In this article, the authors investigated the mechanical properties and oxidation resistance of Al2O3/Ni composites and demonstrated that dissolved oxygen in the nickel increases the yield strength of nickel and enhances the toughness of the composite.

Abstract: Brittle solids can be toughened by the introduction of ductile metallic inclusions. In the present study, the mechanical properties and oxidation resistance of Al2O3/Ni composites are investigated. The oxidation resistance of the ceramic/metal composite (8 × 10−11 g2 cm−4 s−1 at 1300° C) is comparable to that of many silicon nitrides. The fracture toughness of the composite containing 13 vol.% nickel is twice that of alumina alone. The square of the toughness enhancement for composites containing various amounts of nickel exhibits a linear relationship with the product of volume fraction and inclusion size, as predicted in theoretical models. For the alumina/nickel composite system, it is demonstrated that dissolved oxygen in the nickel increases the yield strength of nickel and enhances the toughness of the composite.