A tough nut to crack

  title={A tough nut to crack},
  author={J. Jennings and N. H. Macmillan},
  journal={Journal of Materials Science},
A study of the microstructure and mechanical properties of macadamia nutshells reveals these to behave like an “isotropic wood.” Their dry density is ∼ 1.3×103kgm−3, their Vickers hardness is 180±30 MPa, their fracture strength is 25 to 80 MPa and their fracture toughness is 1 to 2MPam1/2. Their Young's modulus probably lies nearer the highest (6GPa) than the lowest (2GPa) of the present measurements and their work of fracture lies in the range 100 to 1000 Jm−2. None of the mechanical… Expand
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