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Spinodal strain glass in Mn-Cu alloys.
- Source :
-
Acta Materialia . Jun2022, Vol. 231, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
Abstract
- Strain glasses (STGs), which are characterized by nanodomains of martensite formed via a strain glass transition, can produce many unusual properties not possessed by normal martensitic alloys. These nanodomains originate from the formation of short-range strain ordering by the disruption of otherwise long-range strain ordering or normal martensitic transformation through sufficient atomic/nanoscale random stress/strain field. So far the atomic/nanoscale randomness is known to be from either point defects, dislocations, or nanoprecipitates. Here we report a spinodal STG alloy Mn 60 Cu 40 , which stems from nanoscale composition modulations (5-20 nm) formed in the early stage of spinodal decomposition, which is identified by STEM-EDS and HRTEM. For short-time (<50 min) aged sample, a strain glass transition was identified by its typical signatures including invariance of global face-centered cubic (fcc) structure with cooling, frequency dependence of elastic moduli at STG transition temperature (T g) following a Vogel-Fulcher relationship, non-ergodicity as manifested by zero-field-colling/field-cooling curves, and the formation of martensitic face-centered tetragonal (fct) nanodomains. For long-time (≥50 min) aged sample, a normal martensitic transition from fcc to fct appears with cooling, being consistent with literatures. As the result, a temperature vs. aging-time phase diagram of spinodal STG was established and shows a crossover from STG to martensite above a critical aging time. The spinodal STG exhibits a non-magnetic Elinvar behavior, i.e., nearly constant elastic modulus over a wide temperature range, together with high-damping capacity. We anticipate that the spinodal STG and associated novel properties may also be found in other metallic and ceramic spinodal materials. [Display omitted] [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 13596454
- Volume :
- 231
- Database :
- Academic Search Index
- Journal :
- Acta Materialia
- Publication Type :
- Academic Journal
- Accession number :
- 156453167
- Full Text :
- https://doi.org/10.1016/j.actamat.2022.117874