Fatigue crack growth properties in SiC particulate-reinforced cast aluminum alloy composites
Fatigue crack growth properties in SiC particulate-reinforced cast aluminum alloy composites
复制标题
SiC颗粒增强铸造铝合金复合材料的疲劳裂纹扩展性能
DOI：
10.2464/jilm.45.309
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
S. Nunomura
中科院分区：
文献类型：
--
作者：
J. Hu;S. Kumai;A. Sekikawa;Y. Higo;S. Nunomura
研究了碳化硅颗粒增强铸造铝合金复合材料的体积分数、凝固组织和颗粒分布对疲劳裂纹扩展性能的影响。与未增强的基体合金相比，铸态复合材料的疲劳裂纹扩展抗力在低ΔK区有所提高，在高ΔK区有所恶化，在Paris区相当。这与粉末冶金复合材料的裂纹扩展行为相对应，具有细小的基体组织和均匀的颗粒分布。然而，铸态复合材料的疲劳裂纹扩展特性受凝固组织的影响。含有不均匀颗粒的枝晶凝固组织导致了复杂的裂纹扩展路径，这种颗粒偏析对疲劳裂纹扩展性能既有积极的影响，也有消极的影响。由于显著的裂纹偏转和由此产生的粗糙度导致的裂纹闭合，它提高了低ΔK区的疲劳裂纹扩展抗力。同时，由于增强的单调断裂模式贡献，使高ΔK区疲劳裂纹扩展性能变差。
Effects of the volume fraction, solidification structure and particle distribution on fatigue crack growth properties in SiC particulate-reinforced cast aluminum alloy composites have been investigated. Comparing with the un-reinforced matrix alloys, fatigue crack growth resistance of the cast composites is found to be improved at the low ΔK region, deteriorated at the high ΔK region, and comparable at the Paris region. These correspond to the crack growth behaviour of the powder metallurgy-processed composites which exhibit fine matrix microstructure and homogeneous particle distribution. However, fatigue crack growth characteristics of the cast composites are influenced by the solidification structure. The dendritic solidification structure including non-uniform particle distribution results in complicated crack growth path, and such the particle segregation provides both positive and negative effects for the fatigue crack growth properties. It improves fatigue crack growth resistance at the low ΔK region due to the remarkable crack deflection and the resultant roughness-induced crack closure. While, it deteriorates the high ΔK region fatigue crack growth properties due to the enhanced monotonic fracture mode contribution.