Threshold Stress for Crack Healing of Mullite Reinforced by SiC Whiskers and SiC Particles and Resultant Fatigue Strength at the Healing Temperature
Threshold Stress for Crack Healing of Mullite Reinforced by SiC Whiskers and SiC Particles and Resultant Fatigue Strength at the Healing Temperature
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DOI：
10.1111/j.1551-2916.2007.01726.x
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发表时间：
2007-07
影响因子：
3.9
通讯作者：
Koji Takahashi;K. Uchiide;Y. Kimura;W. Nakao;K. Ando;M. Yokouchi
中科院分区：
文献类型：
--
作者：
Koji Takahashi;K. Uchiide;Y. Kimura;W. Nakao;K. Ando;M. Yokouchi
采用热压法制备了具有良好裂纹愈合能力和力学性能的莫来石/SiC晶须/SiC颗粒多元复合材料，研究了应力作用下的裂纹愈合行为和愈合温度下的疲劳强度。在每个试样上引入一个表面长度为100 μm的半椭圆形表面裂纹。在1473 K下，通过使用三点弯曲应力，在循环或恒定应力下对预裂纹试样进行裂纹愈合，并在1473 K下测量所得的弯曲强度和循环疲劳强度。试样表面的预裂纹在应力作用下也能愈合。裂纹愈合的阈值应力，确定通过评估裂纹愈合的试样在愈合温度为1473 K的强度，为170 MPa的恒定和循环应力，对应于77%的预开裂试样的弯曲强度。在1473 K的愈合温度下，研究了裂纹愈合试样的静态和循环疲劳行为。
A mullite/SiC whisker/SiC particle multi-composite, having excellent crack-healing ability and mechanical properties, was hot pressed in order to investigate the crack-healing behavior under stress and the resultant fatigue strength at the temperature of healing. A semi-elliptical surface crack 100 μm in surface length was introduced on each specimen. The pre-cracked specimens were crack healed under cyclic or constant stress by using a three-point bending stress at 1473 K, and the resultant bending strength and cyclic fatigue strength were measured at 1473 K. The pre-crack on the surface of the specimens could be healed even under stress. The threshold stresses for crack healing, as determined by evaluating the strengths of crack-healed specimens at a healing temperature of 1473 K, were 170 MPa for both constant and cyclic stresses, corresponding to 77% of the bending strength of the pre-cracked specimens. The static and cyclic fatigue behaviors of crack-healed specimens were also investigated at a healing temperature of 1473 K.