Thermal Stability of Ni-Mn Electrodeposits
- Sandia National Laboratories (SNL)
- IBM T. J. Watson Research Center
- ORNL
The effect of Mn additions on the structural stability of electrodeposited Ni is investigated by comparing the microstructure evolution of Ni and Ni-Mn specimens with similar crystallographic initial textures. As deposited, Ni-Mn electrodeposits have a smaller crystallite size and substantially higher yield strength than Ni deposits, in agreement with the Hall-Petch relationship. Moreover, dilute Ni-Mn electrodeposits exhibit a thermal stability that significantly exceeds that of pure Ni. Indeed, Ni-Mn retains its texture, fine-grain microstructure, and strength above 500 C (for 1 h anneal), and does not recrystallize up to 800 C. In contrast, pure Ni with larger average grain size and similar preferred orientation shows abnormal grain growth at 300 C and recrystallization at 600 C. This study suggests two distinct temperature regimes. Below 600 C, grain boundary segregation appears as a plausible mechanism for the thermal stability of Ni-Mn electrodeposits, whereas grain boundary pinning by precipitation contributes to the improved microstructural stability of Ni-Mn above 600 C.
- Research Organization:
- Oak Ridge National Laboratory (ORNL); Shared Research Equipment Collaborative Research Center
- Sponsoring Organization:
- SC USDOE - Office of Science (SC)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1003550
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 7 Vol. 54; ISSN 1359-6454
- Country of Publication:
- United States
- Language:
- English
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