氮化硅陶瓷涡轮转子可靠性问题是制约废气涡轮增压器发展的主要瓶颈。课题利用动态试验观察与静态裂纹扩展阻力和抗热震性测量相结合的手段，拟定预制裂纹扩展量测量和超速超温实验方案，对氮化硼纳米管(BNNT)增韧补强氮化硅陶瓷涡轮的离心应力、振动应力和热应力的耦合下微观结构的演变损伤规律和性能的不可逆循环累积衰减机制展开研究，提出"反棘轮行为"概念，重点阐述BNNT近场的应力屏蔽和缓冲对消除裂纹萌生和减少裂纹扩展的反棘轮效应，阐明BNNT的反棘轮行为对消减结构演变损伤和抑制性能累积衰减的作用机制。通过涡轮叶片温度场和应力场的模拟仿真及数值分析和数理统计与计算，构建动态模拟实验条件下非稳态脉冲气流冲击的涡轮叶片抵御断裂和热力冲击损伤的循环累积反棘轮本构模型，揭示反棘轮行为对抑制性能衰退、减缓演化损伤的规律，澄清BNNT增韧补强机理，为其在非稳态热力耦合作用下的可靠性使用提供理论基础支撑。

Reliability of turbine rotor fabricated by silicon nitride ceramic is a major bottleneck restricting the development of the exhaust gas turbocharger.Using the research methods as dynamic tests combining with static crack propagation resistance and thermal shock resistance measurement,and applying the experimental scheme as prefabricated crack propagation measurement, overspeeding and over temperaturing test, the reliability of turbine fabricated by Si3N4 ceramics toughened and reinforced BNNT is being studied.And the negative ratchetting behavior concept was put forward. The negative ratchetting effect of BNNT which can reduce microstructure evolution damage and restrain performance cumulative deterioration was studied. By stress shielding and buffering near field of BNNT, the crack initiation is eliminated and the crack propagation is reduced.Through simulating the temperature field and stress field of the turbine blade and numerical analysis as well as mathematical statistics calculation, the negative ratchetting constitutive model of turbine blade against fracture and thermal shock damage of unsteady pulse air impact will be established. These will reveal the negative ratchetting behavior to the regular pattern of suppressing on performance recession and slowing damage evolution, clarify BNNT toughening mechanism and provide a theoretical basis of support for its reliability in non-steady-state thermal coupling.