Mechanical properties of dry-pressed powder compacts: Case study on alumina nanoparticles

Youngs modulus and fracture toughness of dry-pressed powder compacts of nanocrystalline alumina powders have been determined for different relative densities and average grain size. The powder with a grain size of 40 nm yielded a maximum Youngs modulus of 15 GPa and a peak fracture toughness of 0.12 MPa .m1/2. These high values are rationalized using a model based on contact flattening between particle spheres, which allows a discussion of the influence of grain size and particle packing on the mechanical properties of green bodies.