TC18钛合金疲劳断裂过程声发射信号特征分析  

Analysis of Acoustic Emission Signals Characteristics for TC18 Titanium Alloy Fatigue Fracture Process

作　　者：张昭[1] 肖迎春[1] 王倩[1] 郑建军[1] 

机构地区：[1]中国飞机强度研究所结构无损检测及健康监测研究室,西安710065

出　　处：《航空工程进展》2015年第4期502-506,共5页Advances in Aeronautical Science and Engineering

摘　　要：声发射技术通过实时监测结构服役过程中发出的声发射信号,判断结构是否出现损伤,是一种重要的在线监测损伤的技术。为了明确TC18钛合金在疲劳试验中产生微裂纹、裂纹扩展及断裂等过程中声发射信号的特性,设计TC18钛合金试验件,进行其疲劳试验并全程采集声发射信号;采用参数分析方法,得到声发射信号在时域、频域方面的参数特征。结果表明：在裂纹萌生及扩展阶段,声发射信号幅值为40~65dB,低于相同条件下铝合金的信号幅值;在200~280kHz频段上,裂纹萌生阶段与后续过程的能量分布存在较大差异。结合上述研究结果,给出TC18钛合金试验件声发射监测的参考原则。Acoustic emission can real-time monitor acoustic emission signals by structure service process and judge the structural damage.Acoustic emission is an important technique for on-line monitoring of damage.The feature of acoustic emission signals is figured out,which are produced by the cracks in titanium alloy of TC18,when the crack initiates,and grows until the TC18 sample is broken.TC18 samples and fatigue test are designed,and acoustic emission signals are acquired along the test.The feature parameters of time domain and frequency domain using parametric method are gained.The results show that in the crack initiation and expansion stage,acoustic emission signal amplitude in the 40~65dB,lower than under the same conditions of aluminum alloy signal amplitude and in the 200~280kHz band crack initiation stage and follow-up process of energy distribution,there is a big difference.Finally the reference comments of acoustic emission monitoring in titanium alloy of TC18 samples are given.

关 键 词：TC18 钛合金 疲劳试验 声发射 特征参数 

分 类 号：V25[一般工业技术—材料科学与工程] V26[航空宇航科学与技术—航空宇航制造工程]