镁合金拉伸过程中损伤模式的声发射识别（英文）

发布时间：2018-05-16 03:43

本文选题：声发射 + 多参数分析　；参考：《Transactions of Nonferrous Metals Society of China》2015年06期

【摘要】：为了识别不同的损伤模式,采用声发射技术对AZ31镁合金拉伸开裂过程进行实时监测。结果显示,拉伸开裂经历了弹性变形、塑性变形、微开裂、稳定扩展和失稳扩展的损伤过程。通过声发射的多参数分析,确定了4种损伤模式,即塑性变形、微开裂、稳定扩展和失稳扩展。位错滑移导致的塑性变形信号幅度小于70 d B,而孪晶信号的幅度位于70~100 d B之间。微开裂信号能量位于2400到4100 a J之间,而信号上升时间小于800μs。稳定裂纹扩展信号具有较高的峰值前计数,主要分布在20~50范围内,而其振铃总计数却较低,主要分布在20~2000范围内。裂纹失稳扩展信号的平均频率分布在100 k Hz左右,持续时间在2000~105μs范围内。还对不同开裂阶段的损伤机理和声发射源进行了讨论。通过实验测试和讨论,利用不同的声发射信号参数,可以有效识别镁合金开裂过程中同时出现的不同损伤形式。
[Abstract]:In order to identify different damage modes, acoustic emission (AE) technique was used to monitor the tensile cracking process of AZ31 magnesium alloys in real time. The results show that the tensile cracking has experienced the damage process of elastic deformation, plastic deformation, micro-cracking, stable propagation and unstable propagation. Through the multi-parameter analysis of acoustic emission, four damage modes, namely plastic deformation, micro-cracking, stable propagation and unstable propagation, are determined. The amplitude of plastic deformation signal caused by dislocation slip is less than 70 dB, while the amplitude of twin signal is between 70 dB and 100 dB. The energy of microcracking signal is between 2400 and 4100 J, and the signal rising time is less than 800 渭 s. The stable crack propagation signal has a high peak count, mainly distributed in the range of 20 ~ 50, but the total number of ringing is lower, mainly in the range of 20 ~ 2000. The average frequency distribution of the crack instability propagation signal is about 100kHz and the duration is in the range of 2000105 渭 s. The damage mechanism and acoustic emission source at different cracking stages were also discussed. Through experimental test and discussion, different damage forms of magnesium alloy during cracking can be effectively identified by using different acoustic emission signal parameters.
【作者单位】：深圳职业技术学院工业中心;
【基金】：Project(2213K3170027) supported by the Shenzhen Polytechnic Project Fund,China
【分类号】：TG146.22;TG115

【共引文献】