(1. 中国科学院金属研究所，沈阳 110016；
2. 宝钛集团有限公司，宝鸡 721014)
摘 要: 比较不同显微组织条件下TC4ELI合金的断裂韧性，并从断裂韧性本质定义的角度分析影响材料断裂韧性的因素。不同状态下TC4ELI合金断裂韧性值表明，片层组织具有较高的断裂韧性，且断裂韧性大体上随屈服强度的升高而降低。从疲劳裂纹尖端塑性区的角度阐述了影响材料断裂韧性的因素。
关键字: 钛合金；断裂韧性；裂纹尖端塑性区
（1. Institute of Metal Research, Chinese Academic of Sciences, Shenyang 110016, China;
2. Baoji Titanium Group Co. Ltd, Baoji 721014, China）
Abstract:Fracture toughness KIC of TC4ELI alloys with different microstructures was tested, and the essential definition of KIC was introduced to explain the influence of microstructure on KIC. The results show that lamellar microstructure has high KIC value, and the KIC value increases with the decreasing of yield stress. Finally the crack tip plastic zone CTPZ was introduced to interpret the variations of KIC.
Key words: titanium alloy; fracture toughness; crack tip plastic zone
