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铸造Ti6Al4V钛合金疲劳裂纹扩展特性的研究
Fatigue Crack Growth Rate for Ti6Al4V Casting Titanium Alloy
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- DOI:
- 作者:
- 马丽1,上官晓峰2,要玉宏2,陈迎旭2
- 作者单位:
- 1.西安工业大学北方信息工程学院,陕西 西安 710025;2.西安工业大学材料与化工学院,陕西 西安 710032
- 关键词:
- Ti6Al4V;裂纹扩展速率;断裂机理
Ti6Al4V; Fatigue crack growth rate; Fracture mechanism
- 摘要:
按照GB63981986试验标准,采用紧凑拉伸试样(CT)测定了铸造Ti6Al4V钛合金疲劳
裂纹扩展速率da/dN,采用扫描电镜(SEM)等现代技术对断口形貌进行观察,分析了不同应力比(R值)条件下的疲劳裂纹扩展特性。结果表明,应力比R对铸造Ti6Al4V钛合金的裂纹扩展速率影响较大,应力比R越大,裂纹扩展速率越大。在裂纹预裂区和快速扩展的断裂机理主要是以微区解理断裂为主,
稳态扩展区主要是以疲劳条带扩展机制为主,同时也存在微区解理断裂机制。
The fatigue crack growth rate (da/dN) for Ti6Al4V casting titanium
alloy was obtained by measuring compact tension specimen according to the teste
d standard of GB63981986. Fracture was observed by SEM (scanning Election Micr
oscope),and the fatigue crack growth feature at different R values were discuss
ed. The results show that stress ratio (R) affects the fatigue crack growth
rate, and the da/dn increase with increasing R. At preplitting
area and rapid propagation area are cleavage fracture, at steady growth area th
e fracture mechanism is fatigue braids mechanism, and cleavage fracture is also
existed.