Simulation of nacre with TiC/metal multilayers and a study of their toughness

Multilayers of TiC and a series of metals have been prepared by ion beam sputtering deposition to simulate nacre. The individual layer thickness varies from 1 to 10 nm, and the thickness of the films is about 1 micron. TEM, LXRD and HREM show their periodicity and lattice images. A particular method is devised to evaluate the relative toughness of these artificial pearlite structures. It is shown that the toughness of these nanocomposite materials can be tremendously improved. A maximum of toughness appears at certain modulation. Metals with high plasticity such as Al and Cu can produce particularly spectacular effect on increasing the toughness of these multilayers.