【摘要】 针对外物损伤(FOD)对航空发动机宽弦空心风扇叶片高循环疲劳(HCF)性能的影响,以TC4合金3层扩散焊板件模拟宽弦空心风扇叶片典型冲击部位,采用空气炮法对TC4合金3层扩散焊板进行FOD模拟试验,对冲击角度为25°、40°和80°时的损伤状况进行了宏微观测量;采用逐级加载法对FOD后的扩散焊焊板进行HCF强度试验,获得各条件下扩散焊板件的条件疲劳极限。结果表明:在各冲击条件下,冲击角度为25°时对材料造成的损伤最严重,HCF强度降低幅度最大;FOD不仅会造成材料表面损伤,还会对内部焊缝层造成损伤。在上述因素共同作用下,扩散焊板件FOD后HCF强度显著降低,相应的疲劳缺口系数明显增大。更多还原

【Abstract】 Typical impact position of hollow wide-chord fan blades were imitated by TC4 alloy three-layer diffusion welding plate for the effect of foreign object damage(FOD)on high cycle fatigue(HCF)performance of aeroengine hollow wide-chord fan blades. The FOD simulation test of TC4 alloy three-layer diffusion welding plate was carried out by air-gun method and the damage condition of TC4 alloy was measured by macrography and microcosmic measure when the impact angle was 25°, 40° and 80°. The fatigue limit of diffusion welding plate was obtained under various conditions by HCF strength test of diffusion welding plate using stepwise loading method after FOD. The results show that the damage of plate and the decrease of HCF strength are the most serious under various impact conditions when the impact angle is 25°. FOD can not only cause damage to the surface of material,but also cause damage to the inner welding layer. The HCF strength of diffusion welding plate decreased significantly after FOD, and the corresponding fatigue notch coefficient increased obviously under the combined action of the above factors.更多还原