Progress in stress-relieving methodologies of ceramic matrix composites/ Ni-based superalloys joints: A review

Ceramic matrix composites (CMCs) are regarded as promising high-temperature materials for industrial applications due to their exceptional properties at elevated temperatures. However, their limited manufacturability restricts their capability to be produced as complex, large-scale structural components. Ni-based superalloys are well-known for their outstanding performance under high-temperature conditions. The integration of these two material types to create hybrid components can significantly broaden their applications in engineering. A critical challenge arises from the interfacial residual stresses that develop at the joints of CMCs and Ni-based superalloys, which can severely impair the performance of the hybrid components. The mechanisms behind the formation of residual stress in CMCs/Ni-based superalloys joints are reviewed, including thermal expansion coefficient (CTE) mismatch, thermal gradient difference, and phase transformation, and various methodologies for alleviating these stresses are summarized, including interlayer techniques, composite filler approaches, and interface structure design strategies. Finally, the challenges and future trends in mitigating interfacial stress in CMCs/Ni-based superalloys joints are discussed.