航空用新型低成本钛合金显微组织与损伤容限性能关系研究

利用扫描电镜对某新型航空用Ti—A1-Mo—Cr—Zr系低成本钛合金的双态组织、片层组织及网篮组织3种典型显微组织特征和裂纹扩展过程进行了观察和分析，并对具有不同类型显微组织的合金进行了拉伸、断裂性能和疲劳性能的检测。结果表明：该新型Ti—A1-Mo—Cr—Zr系高性能低成本钛合金在不同显微组织下均具有良好的强度-塑性-韧性-疲劳性能的匹配。其中，双态组织的该合金具有最高的强度和塑性，但损伤容限性能较低（断裂韧性稍低，疲劳裂纹扩展速率高）；网篮组织的该合金具有良好的断裂韧性和疲劳强度，疲劳裂纹扩展速率与双态组织的水平相当；片层组织的该合金具有最为优异的损伤容限性能（最低的疲劳裂纹扩展速率和最高的断裂韧性），但疲劳极限、强度和塑性稍低于双态组织和网篮组织的该合金。

Research of the Relationship Between Microstructure and Damage-Tolerance Property of New Low Cost Titanium Alloy in Aviation Applications

The typical microstructure characteristics and the crack propagation process of a new kind of low cost Ti-A1-Mo-Cr-Zr system titanium alloy in aviation applications were observed and analyzed by scanning electron microscopy （SEM）. The tensile, toughness and fatigue properties of the new alloy under different microstructure types were detec-ted. The results show that the new kind of low cost Ti-A1-Mo-Cr-Zr system titanimn alloy has good strength-plastic-toughness-fatigue properties matching under different microstructure types. The titanium alloy of hi-modal structure has the highest strength and ductility, but has the slowest damage-tolerance property. And basket structure has higher toughness property and fatigue limit, of which the fatigue crack propagation rate has the same level of bi-modal struc-ture, lamellar structure has the highest damage-tolerance property, of which the fatigue limit, strength and ductility is lower than hi-modal and basket structure.