Detection of formation and annihilation process of point defects produced by three deformation modes using Cu precipitation behavior in Fe‐Cu alloy

Abstract

Specimens of pure Fe, Fe-0.15wt.%Cu and Fe-0.6wt.%Cu were deformed with 10% strain by three deformation modes (rolling, compression and tension), and were measured using positron annihilation spectroscopy after annealing from 373 K to 873 K per 100 K for 1 hour. The positron annihilation lifetime of vacancies after deformation was about 135 psec, and most of the vacancies produced by deformation were expected to be trapped at the dislocation core, and were released from it at 573 K. In Fe-0.15%Cu, Cu precipitates were not produced, and the formation and annihilation behavior of vacancies was similar to pure Fe. In each deformation, cell structures were different, so, in the Fe-0.6%Cu, growth of Cu precipitates was different. The tension, rolling and compression were ranked in a descending order of degree of contribution of the vacancies released from the dislocations to the growth of Cu precipitation.

In situdetermination of aging precipitation in deformed Fe-Cu and Fe-Cu-B-N alloys by time-resolved small-angle neutron scattering

“…The dislocation structure will generally vary with the deformation mode, strain level, and strain rate. 41,43,39 In the early-stage precipitation regime ͑Ͻ4 h͒ copper precipitation at dislocations is strongly promoted by the prestrain in the Fe-Cu alloy. When N and/or B are added to the alloy, we see that the precipitation of copper at dislocations is largely suppressed.…”

Defect structures in nickel and SUS304SS formed by the collapse of cavitation bubbles

“…The defect structures depend on the deformation mode [9] and deformation speed [10]. It is highly likely that the cavitation damage corresponds to high-speed deformation since calculations yielded a mercury jet speed of 300 m/s [6].…”