TiC/metal nacrous structures and their fracture toughness increase

Abstract

Multilayers of TiC and a series of metals have been fabricated by ion beam sputtering deposition to simulate nacre. The individual layer thickness varies from 1 to 10 nm, and the total thickness of the multilayers is about 1 μm. Transmission electron microscopy (TEM), low-angle x-ray diffraction (LXRD), and high-resolution electron microscopy (HREM) show their periodicity and lattice images. A particular method is devised to evaluate the relative toughness of this artificial pearlite. It is shown that the toughness of these nanocomposite materials can be tremendously improved. A maximum of toughness appears at a certain modulation. Metals with high plasticity such as Al and Cu can produce a particularly spectacular effect on increasing the toughness of these multilayers.