Open AccessPOSITRON ANNIHILATION STUDY ON DEFORMATION OF HIGH PURITY IRON UNDER DIFFERENT STRAIN RATE
Author(s) -
Yunhai Wu,
Tian Zhongzhuo,
Chang Xiangrong,
Jijun Xiao
Publication year - 1991
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.40.1879
Subject(s) - materials science , strain rate , saturation (graph theory) , strain (injury) , dislocation , positron annihilation , vacancy defect , deformation (meteorology) , doppler broadening , tensile testing , condensed matter physics , ultimate tensile strength , composite material , positron , nuclear physics , physics , spectral line , medicine , electron , mathematics , combinatorics , astronomy
Variation of S-parameter with the strain (S-ε curve) under different strain rate are investigated by combining Doppler broadening measurement with slow tensile test. Experimental results are as follows:1. Under slow strain rate, the S-ε curve in high purity iron does not tend to saturation. The slower the strain rate is, the more evident the "non-saturation phenomenon".2. Variations of S-ε curve with strain rate are attributed to the different configuration of dislocation distribution under different strain rates.3. As high purity iron is deformed, the increment of S-parameter depends not only on dislocation density but also on vacancy concentration, and we attibute the so called "non-saturation phenomenon" of S-ε curve to the strain induced vacancies.