In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 22, No. 2 ( 2007-02), p. 314-325
Abstract:
Starting with a bulk metallic glass-forming alloy Mg 65 Cu 18 Ni 6 Y 11 , we prepared in situ composites by increasing the Mg content in a series of alloys, Mg x (Cu 0.51 Ni 0.17 Y 0.32 ) 100− x (65 ≤ x ≤ 90), via copper mold casting of rods 4 mm in diameter. The fully glassy alloy at x = 65 showed a compressive fracture strength of 755 MPa but no observable macroscopic plasticity prior to failure. Metallic glass-based composites were formed when the Mg content was increased. For x 〉 80, the glassy phase no longer existed in the as-cast rods. In the composition range of 80 ≤ x ≤ 85, needle-shaped Mg solution with a 14H-type long period stacking (LPS) structure appeared as the primary phase in the as-cast microstructure. On further increase of the Mg content up to x = 90, the solidified primary phase became 2H-Mg, coexisting with the remaining eutectic structure. The best combination of mechanical properties was obtained for the alloy at x = 81.5, which showed a fracture strength of 665 MPa and a compressive plastic strain of 11.6%. The specific strength of this alloy was 2.8 × 10 5 N m kg −1 , much higher than conventional cast magnesium alloys. The mechanical properties are discussed in light of the phase selection and microstructural features uncovered in microscopy examinations.
Type of Medium:
Online Resource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/jmr.2007.0032
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2007
detail.hit.zdb_id:
54876-5
detail.hit.zdb_id:
2015297-8
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