Abstract

High cycle fatigue (HCF) and fatigue crack propagation (FCP) behaviors of β-annealed Ti64 alloys having a microstructure of either α colonies or basketweave were studied. It was found that the resistance to HCF of β-annealed Ti64 alloys with a microstructure of α colonies was similar but slightly inferior to those with a microstructure of basketweave. On the other hand, the FCP rates of β-annealed Ti64 alloys having a microstructure of α colonies were lower than those of basketweave, particularly in low ΔK regime. Crack path observation on the surfaces of β-annealed Ti64 alloy specimens suggested that crystallographic crack growth prevailed in the microstructure of α colonies, leaving cleavage facets on the fracture surface and less fatigue damage at the tip of crack. Based on the fractographic and micrographic examination, the effects of microstructure on the HCF and FCP behaviors of β-annealed Ti64 alloys were discussed.

Graphic Abstract

抽象的

研究了具有α菌落或篮状组织的β退火Ti64合金的高循环疲劳（HCF）和疲劳裂纹扩展（FCP）行为。已经发现，具有α菌落的微观结构的β退火Ti64合金对HCF的抵抗性相似，但与具有篮状组织的微观结构相比，其对HCF的抵抗性稍差。另一方面，具有α菌落的微观结构的β退火Ti64合金的FCP率低于网状组织，特别是在低ΔK状态下。在β退火的Ti64合金试样表面的裂纹路径观察表明，晶体裂纹扩展普遍存在于α菌落的微观结构中，在断裂表面留下了分裂面，并且在裂纹尖端的疲劳损伤较小。根据分形和显微检查，

图形摘要