In-Situ Nuclear Magnetic Resonance Investigation of Strain, Temperature, and Strain-Rate Variations of Deformation-Induced Vacancy Concentration in Aluminum

K. Linga Murty, K. Detemple, O. Kanert, J.Th.M. De Hosson

Research output: Contribution to journalArticleAcademicpeer-review

36 Citations (Scopus)
313 Downloads (Pure)


Critical strain to serrated flow in solid solution alloys exhibiting dynamic strain aging (DSA) or Portevin–LeChatelier effect is due to the strain-induced vacancy production. Nuclear magnetic resonance (NMR) techniques can be used to monitor in situ the dynamical behavior of point and line defects in materials during deformation, and these techniques are nondestructive and noninvasive. The new CUT-sequence pulse method allowed an accurate evaluation of the strain-enhanced vacancy diffusion and, thus, the excess vacancy concentration during deformation as a function of strain, strain rate, and temperature. Due to skin effect problems in metals at high frequencies, thin foils of Al were used and experimental results correlated with models based on vacancy production through mechanical work (vs thermal jogs), while in situ annealing of excess vacancies is noted at high temperatures. These correlations made it feasible to obtain explicit dependencies of the strain-induced vacancy concentration on test variables such as the strain, strain rate, and temperature. These studies clearly reveal the power and utility of these NMR techniques in the determination of deformation-induced vacancies in situ in a noninvasive fashion.
Original languageEnglish
Pages (from-to)153-159
Number of pages7
JournalMetallurgical and Materials Transactions A-Physical Metallurgy and Materials Science
Issue number1
Publication statusPublished - 1998
EventSymposium on Fundamentals of Gamma Titanium Aluminides at the TMS Annual Meeting -
Duration: 10-Feb-199712-Feb-1997


  • NACL

Cite this