Contributions to the Interfacial Adhesion in Co-Sintered Bilayers

摘要

The adhesive strength of co-sintered bilayers is influenced by several factors, including the nature of bonding along the joined interface, residual stresses evolved during processing, and the sintered properties of the individual layers. Here these separate contributions are isolated through careful control of the co-sintering process for W/Al_2O_3 bilayers, and in particular through control of the W-layer properties by using the process of activated sintering. Four-point bending delamination tests are used to evaluate adhesion and strength of the bilayers, and the interfacial fracture mechanics of the system is numerically studied using finite element simulations. Improvements in sintered density are found to increase the adhesive strength of the system only up to a point, beyond which shrinkage mismatch compromises the intrinsic toughness of the interface.