文献类型：期刊文献

英文题名：Creep damage characterization using nonlinear ultrasonic guided wave method: A mesoscale model

作者：Xiang, Yanxun[1];Deng, Mingxi[2];Xuan, Fu-Zhen[1]

机构：[1]E China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, MOE, Shanghai 200237, Peoples R China;[2]Logist Engn Univ, Dept Phys, Chongqing 400016, Peoples R China

年份：2014

卷号：115

期号：4

外文期刊名：JOURNAL OF APPLIED PHYSICS

收录：;EI(收录号：20144100085907);WOS:【SCI-EXPANDED(收录号:WOS:000331210800136)】；

基金：The authors are grateful for the supports provided by National Natural Science Foundations of China (Grant Nos. 51325504, 11004056, and 11274388).

语种：英文

外文关键词：Guided electromagnetic wave propagation - Nondestructive examination - Precipitates - Ultrasonic testing - Titanium alloys - Surface waves - Ultrasonic waves - Precipitation (chemical)

摘要：The early deformations in materials such as creep, plasticity, and fatigue damages have been proved to have a close relationship with the nonlinear effect of ultrasonic waves propagating in them. In the present paper, a theoretical mesoscale model of an ultrasonic non-destructive method has been proposed to evaluate creep deformed states based on nonlinear guided waves. The model developed here considers the nonlinear generation of Lamb waves response from precipitates variation in the dislocation network, which can be applicable to all precipitate stages including coherent and semi-coherent precipitates in the metallic alloy undergoing creep degradation. To verify the proposed model, experiments of titanium alloy Ti60 plates were carried out with different creep strains. An "increase-decrease" change of the acoustic nonlinearity of guided wave versus the creep life fraction has been observed. Based on microscopic images analyses, the mesoscale model was then applied to these creep damaged Ti60 specimens, which revealed a good accordance with the measured results of the nonlinear guided waves. It is shown that the change of the nonlinear Lamb wave depends on the variations of the alpha 2 precipitation volume fraction, the dislocation density, the growth of the creep-voids, and the increasing mismatch of the phase velocities during the creep deformation process. The results indicate that the effect of the precipitate-dislocation interactions on the nonlinear guided wave is likely the dominant mechanism responsible for the change of nonlinear guided wave propagation in the crept materials. (C) 2014 AIP Publishing LLC.