应变幅值对双态组织TC4钛合金疲劳断裂机制的影响  

Effect of Strain Amplitude on Fatigue Fracture Mechanism of TC4 Titanium Alloy with Duplex Structure

作　　者：王琨 李艳青[1] 王雷[1] 黄进浩[1] 陈鹏[1] WANG Kun;LI Yanqing;WANG Lei;HUANG Jinhao;CHEN Peng(China Ship Scientific Research Center, Wuxi 214082, China)

机构地区：[1]中国船舶科学研究中心

出　　处：《热加工工艺》2018年第10期86-89,共4页Hot Working Technology

摘　　要：测试了双态组织TC4钛合金的低周疲劳性能,并结合断口形貌及断口附近组织,分析了应变幅对双态组织TC4钛合金低周疲劳过程中断裂机制的影响。结果发现：双态组织的TC4钛合金在遭受小应变幅（0.6%）时,寿命较长,在10000次以上;当应变幅为1.2%时,其寿命仍能保持在600次以上。在遭受大应变幅（1.2%）时,裂纹穿过相而扩展,材料内部缺陷是裂纹萌生源;当遭受小应变幅（0.6%）时,裂纹源出现在材料表面,α相被拉长,裂纹沿α相和β转变组织之间扩展。The low cycle fatigue performance of TC4 titanium alloy with duplex structure was tested. Combined with fracture morphology and microstructure near fracture. The influences of strain amplitudes on the fracture mechanism of TC4 titanium alloy with duplex structure in the process of low cycle fatigue were analyzed. The results show that the life of the titanium alloy with duplex structure under small strain amplitude is more than 10000 times. When the strain amplitude is1.2%, the titanium alloy remains the life of more than 600 times. When the titanium alloy suffers great strain amplitude（1.2%）and the crack goes through phase and then extends. The internal defect in material is crack initiation source. When the alloy is subjected to small strain（0.6%）, the source of the crack appears on the surface of the materials, the α phase is stretched and the crack extends between the α phase and β transformation microstructure.

关 键 词：低周疲劳 双态组织 TC4钛合金 寿命 

分 类 号：TG113.25[金属学及工艺—物理冶金]