ABSTRACT The thermal expansion mismatch between sapphire and Ti‐6Al‐4V (TC4) alloy has traditionally limited the shear strength of ceramic‐metal joints to ≤ 170 MPa. In this study, active brazing with Ag‐35.25Cu‐1.75Ti (wt%) leads to the formation of a dual‐function microstructure, wherein uniformly dispersed submicron Ti 3 (Cu,Al) 3 O particles embedded in a ductile Ag‐Cu matrix contribute to both Orowan strengthening and reduction in the coefficient of thermal expansion (CTE). Simultaneously, a thin Ti 3 (Cu,Al) 3 O reaction layer forms a coherent interface with sapphire. This tailored microstructure results in an unprecedented shear strength of 218.3 MPa, marking a 29% improvement over previous records. By combining fine‐particle reinforcement, a coherent reaction layer, and mitigation of residual stresses, this approach offers a promising strategy for developing high‐strength ceramic‐metal joints.
Liu et al. (Wed,) studied this question.