摘要
在不同应力比条件下对热挤压变形的Mg-3Al-2Sc合金进行了疲劳试验,分析了应力比对合金裂纹扩展行为和断裂机制的影响。结果表明:在应力幅Δσ=60 MPa时,随应力比的增加,Mg-3Al-2Sc合金疲劳寿命显著降低,裂纹扩展速率提高。在裂纹萌生区和扩展区疲劳断裂机制主要表现为解理断裂,而在瞬断区主要表现为准解理和沿晶断裂的复合断裂机制。
The fatigue tests of hot extruded Mg-3Al-2Sc alloy products have been done with different stress ratio. The effect of stress ratio on the fatigue crackle propagation behavior and fracture micro-mechanism has been analyzed. The results show that when the stress am- plitude is being △σ = 60MPa,fatigue fracture life of the Mg-3Al-2Sc alloy decreases and the fatigue crack propagation rate increases at the condition of stress ratio increasing. At the crackle embryonic zone and spreading zone the fatigue fracture micro-mechanism shows itself mainly as cleavage fracture, at the fracture instantaneous zone the fatigue fracture shows itself as combined fracture micro-mechanism which is composed mainly of quasi-cleavages and inter-crystal-line fractures.
出处
《轻合金加工技术》
CAS
北大核心
2012年第9期60-63,69,共5页
Light Alloy Fabrication Technology
基金
国家自然科学基金(50801048)
航空科学基金(2007ZF54016)
