摘要
细节疲劳强度额定值DFR是结构本身固有的疲劳性能特征值,其在民用飞机疲劳寿命设计和耐久性分析中应用广泛。按HB7110-94金属材料细节疲劳额定强度截止值(DFRcutoff)试验方法对A356.0-T6合金的细节疲劳性能进行研究,根据实验结果计算出DFRcutoff=139 MPa。通过进一步对断口进行扫描电镜观察发现,断口没有明显的疲劳特征,有小解理面和二次裂纹,是明显的脆性断口特征,此外断口还发现有树枝晶,以及气孔、夹杂、疏松等宏观铸造缺陷,铸造质量较差是影响A356.0合金疲劳性能的关键因素。
Detail fatigue rating is the inherent characteristic value of fatigue performance in a structure, which has a wide range of applications on the design of fatigue life and durability analysis in the civil aircraft. According to the test criteria in HB7110-94 by metal DFRcutoff, the fatigue property of A356.0-T6 alloy was tested on the detail fatigue rating. According to the experimental results, the calculated DFRcutoff, is 139 Mpa. No apparent fatigue fracture is revealed from the scanning electron microscope analysis The cleavage surface and second cracks are found, which suggest that the alloy has anobvious characteristic of brittle fracture In addition, dendrites, blowholes, inclusions and shrinkage porosities are found on the fracture. The poor quality of casting is the key factor to affect fatigue propertyof alloy A356.0.
出处
《铸造技术》
CAS
北大核心
2008年第11期1530-1533,共4页
Foundry Technology
