ABSTRACT
Interface fracture toughness of bulk bi-materials has been evaluated on the basis of the fracture mechanics concept (described in Chapter 2), where the conventional experimental methods have been established at the practical level in laboratories [e.g., Rice, 1988; Hutchinson and Suo, 1992; Evans and Dalgleish, 1992]. But evaluating the interface toughness between submicron-or nanometer-thick films and between the films and the substrate presents difficulties because the fabricating and loading such small specimens is restrictive. Although many testing techniques have been proposed [e.g., Evans et al., 1999; Volinsky et al., 2002; Nied, 2003; Thouless, 1994; Lane, 2003], we do not have universal method yet. This section briefly reviews the proposed methods. Table 4.1 summarizes the advantages and disadvantages of each from the standpoint of the applicability of fracture mechanics and the feasibility of sample preparation and handling.
