Microstructural studies of a Cu-Zn-Al shape-memory alloy with manganese and zirconium addition
- City Univ. of Hong Kong, Kowloon (Hong Kong). Dept. of Physics and Materials Science
Mn and Zr were added to improve the shape-memory characteristics of a Cu-Zn-Al shape-memory alloy (SMA). The microstructure of a Cu-19.0Zn-13.1Al-1.1Mn-0.3Zr (at. pct) alloy was examined using a transmission electron microscope (TEM). The structure of the parent phase and martensite phase are DO{sub 3} (or L2{sub 1}) and M18R{sub 1}, respectively. Two kinds of Zr-rich precipitates formed in the alloy. Energy-dispersive X-ray spectroscopy (EDXS) analysis with a TEM indicates that the two precipitates are all new phases and have the compositions of Cu{sub 50.2}Zr{sub 24.6}Al{sub 17.3}Zn{sub 7.9} (at. pct) (Z{sub 1} phase) and Cu{sub 57.4}Zr{sub 20.4}Zn{sub 10.3}Al{sub 11.9} (at. pct) (Z{sub 2} phase), respectively. The volume ratio of Z{sub 1} phase in the alloy is about 70 pct of the total precipitate volume. The structure of Z{sub 1} phase was studied in detail using TEM electron diffraction analyses. The lattice parameter of fcc Z{sub 1} phase is a = 1.24 nm, and the space group of the phase is F432 (No. 209). The Z{sub 1} phase possesses an incoherent interface with the parent-phase matrix. The effect of precipitate formation on the shape-memory characteristics of the Cu-Zn-Al-Mn-Zr alloy is discussed and compared to some other Cu-based SMAs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 634561
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 7 Vol. 29; ISSN 1073-5623; ISSN MMTAEB
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of additions of small amounts of fourth elements on structure, crystal structure and shape recovery of Cu-Zn-Al shape memory alloys
Improvement of the shape memory characteristics of a Cu-Zn-Al alloy with manganese and zirconium addition