Model composites consisting of Si C fiber embedded inβ-Yb_(2)Si_(2)O_(7) matrix were processed by Spark Plasma Sintering method and the feasibility of tunable Si Cf/Yb_(2)Si_(2)O_(7) interface in Si C-based CMCs were...Model composites consisting of Si C fiber embedded inβ-Yb_(2)Si_(2)O_(7) matrix were processed by Spark Plasma Sintering method and the feasibility of tunable Si Cf/Yb_(2)Si_(2)O_(7) interface in Si C-based CMCs were estimated.Weak and strengthened Si Cf/Yb_(2)Si_(2)O_(7) interfaces were achieved by adjusting sintering temperatures.The indentation crack test and fiber push out experiments clearly demonstrated the different debonding mechanisms in the samples.Weak interfaces sintered at 1200 and 1250℃exhibited crack deflection at interface in indentation test.Their low debond energy at the interface,which were comparable to those of Py C or BN,satisfied the well-recognized interfacial debond and crack deflection criteria for CMCs.The interface was strengthened by atomic bonding in model composite sintered at 1450℃,leading to crack penetrating into Si C fiber and high debond energy.The strong interface may be promising in Si Cf/Si C CMC to withstand higher combustion temperature,because Yb_(2)Si_(2)O_(7) will provide plastic deformation capacity,which would serve as weak interphase for crack deflection and energy dissipation.Therefore,it is possible to design the capability of Si C_(f)/RE_(2)Si_(2)O_(7) interface for different requirements by adjusting interfacial strength or debond energy to reach optimal mechanical fuse mechanism in SiC_(f)/SiC CMC.展开更多
基金supported by the National Key R&D Program of China under Grant No.2017YFB0703201Natural Science Foundation of China under Grant No.51772302CAS International Cooperation Key Program under Grant No.174321KYSB20180008。
文摘Model composites consisting of Si C fiber embedded inβ-Yb_(2)Si_(2)O_(7) matrix were processed by Spark Plasma Sintering method and the feasibility of tunable Si Cf/Yb_(2)Si_(2)O_(7) interface in Si C-based CMCs were estimated.Weak and strengthened Si Cf/Yb_(2)Si_(2)O_(7) interfaces were achieved by adjusting sintering temperatures.The indentation crack test and fiber push out experiments clearly demonstrated the different debonding mechanisms in the samples.Weak interfaces sintered at 1200 and 1250℃exhibited crack deflection at interface in indentation test.Their low debond energy at the interface,which were comparable to those of Py C or BN,satisfied the well-recognized interfacial debond and crack deflection criteria for CMCs.The interface was strengthened by atomic bonding in model composite sintered at 1450℃,leading to crack penetrating into Si C fiber and high debond energy.The strong interface may be promising in Si Cf/Si C CMC to withstand higher combustion temperature,because Yb_(2)Si_(2)O_(7) will provide plastic deformation capacity,which would serve as weak interphase for crack deflection and energy dissipation.Therefore,it is possible to design the capability of Si C_(f)/RE_(2)Si_(2)O_(7) interface for different requirements by adjusting interfacial strength or debond energy to reach optimal mechanical fuse mechanism in SiC_(f)/SiC CMC.
