SiCw/LD<sub>2</sub>疲劳裂纹萌生的研究

SiCw/LD₂疲劳裂纹萌生的研究

摘要

摘要: 本文研究SiCw/LD₂复合材料的疲劳裂纹萌生部位、寿命和机制。用TEM现察疲劳试验后材料中的位错分布和出现在晶须旁的微裂纹。用SEM观察疲劳试样的表面一级塑料复型,发现5μm长的表面裂纹。认为复合材料的疲劳强度比基体合金高的一个原因是基体细小的晶粒所导致的较高的疲劳裂纹萌生寿命。
- 复合材料 /
- 疲劳 /
- 裂纹萌生
Abstract: Tne fatigue crack initiation sides,initiation life and mechanisms are studied in a SiCw/LD2 composite.The fatigue microcracks near the ends of whiskers and dislocations in the matrix are observed by TEM.The surface replicas taken from the specimen surfaces duriy fatigue, are examind by SEM, and a 5 micrometer long fatigue crack is found. It is considered that the fine grains can prolong the initiation of fatigue microcracks in the composite,which is one of the reasons leading to the higher fatigur strength of the composite.
- composite /
- fatigue /
- crack initiation