(北京航空材料研究院 先進(jìn)鈦合金航空科技重點(diǎn)實(shí)驗(yàn)室，北京 100095)
摘 要: 研究雙態(tài)組織和網(wǎng)籃組織對(duì)TC32鈦合金高周疲勞(HCF)性能的影響，并與TC4鈦合金等軸組織和TC21鈦合金網(wǎng)籃組織的高周疲勞性能進(jìn)行對(duì)比分析。結(jié)果表明：TC32鈦合金雙態(tài)組織與網(wǎng)籃組織的高周疲勞強(qiáng)度分別為535.7MPa與537.5MPa，明顯高于TC4鈦合金等軸組織的，也高于TC21鈦合金網(wǎng)籃組織的。TC32鈦合金雙態(tài)組織因原始β晶粒細(xì)小，且初生α相與β轉(zhuǎn)變基體強(qiáng)度匹配性良好，不存在異常的平均應(yīng)力敏感性；TC32鈦合金網(wǎng)籃組織因存在較多的二次裂紋，且主裂紋擴(kuò)展路徑曲折，疲勞裂紋擴(kuò)展速率較雙態(tài)組織更緩慢。
關(guān)鍵字: TC32鈦合金；高周疲勞；疲勞斷口；顯微組織
（Aviation Key Laboratory of Science and Technology on Advanced Titanium Alloys,
Institute of Aeronautical Materials, Beijing 100095, China）
Abstract:The high cycle fatigue(HCF) properties were investigated on TC32 titanium alloy with the bimodal and basket microstructures, compared with the HCF properties of TC4 titanium alloy with the equiaxed microstructure and TC21 alloy with the basket microstructure. The results show that TC32 titanium alloy with bimodal and basket microstructures has a much higher HCF strength level compared to that of TC4 titanium alloy with the equiaxed microstructure and has a better HCF strength level than that of TC21 titanium alloy with the basket microstructure, which is 535.7MPa and 537.5MPa, respectively. TC32 alloy with the bimodal microstructure does not show anomalous mean stress sensitivity (AMSS) since its better matching strength between primary α and β phase, and its small grain size. TC32 alloy with the basket microstructure has a greater crack propagation resistance due to main crack deflection and more secondary cracks in propagation region.
Key words: TC32 titanium alloy; high cycle fatigue; fatigue fracture; microstructure
