TY - JOUR
T1 - Acoustic nonlinearity parameter induced by extended dislocations
AU - Gao, Xiang
AU - Qu, Jianmin
N1 - Publisher Copyright:
© 2018 Author(s).
PY - 2018/9/28
Y1 - 2018/9/28
N2 - Excess acoustic nonlinearity is a signature of microstructural defects on a propagating ultrasound. By measuring the excess acoustic nonlinearity parameter, defect characteristics can be inferred nondestructively through ultrasonic techniques. To this end, proper models are needed to relate the excess acoustic nonlinearity parameter with defect characteristics. In this study, an analytical model for extended dislocations is developed that relates the excess acoustic nonlinearity parameter with characteristics of the extended dislocation including dislocation density, stacking fault energy, and equilibrium distance between the two partial dislocations that form the extended dislocation. According to this model, the excess acoustic nonlinearity parameter induced by extended dislocations consists of a stress-independent term and a stress-dependent term. Both terms are scaled with (Lchar/b)n, where Lchar is the equilibrium distance between the two partials, b is the magnitude of Burgers vector, and n is 3 and 4 for the stress-independent and stress-dependent terms, respectively. The model will be useful for interpreting results from ultrasonic nondestructive evaluation of material defects.
AB - Excess acoustic nonlinearity is a signature of microstructural defects on a propagating ultrasound. By measuring the excess acoustic nonlinearity parameter, defect characteristics can be inferred nondestructively through ultrasonic techniques. To this end, proper models are needed to relate the excess acoustic nonlinearity parameter with defect characteristics. In this study, an analytical model for extended dislocations is developed that relates the excess acoustic nonlinearity parameter with characteristics of the extended dislocation including dislocation density, stacking fault energy, and equilibrium distance between the two partial dislocations that form the extended dislocation. According to this model, the excess acoustic nonlinearity parameter induced by extended dislocations consists of a stress-independent term and a stress-dependent term. Both terms are scaled with (Lchar/b)n, where Lchar is the equilibrium distance between the two partials, b is the magnitude of Burgers vector, and n is 3 and 4 for the stress-independent and stress-dependent terms, respectively. The model will be useful for interpreting results from ultrasonic nondestructive evaluation of material defects.
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U2 - 10.1063/1.5046640
DO - 10.1063/1.5046640
M3 - Article
AN - SCOPUS:85054037546
SN - 0021-8979
VL - 124
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 12
M1 - 125102
ER -