A eutectic in La-rich La-Cu₀.₅Ni₀.₅-Al alloys was determined by studying the melting behaviors and the microstructure observations. The microstructures of the La-Cu-Ni-Al alloys prepared by Bridgman Solidification and copper mould casting were studied by using scanning electron microscope (SEM). The results show that La₆₆[Cu₀.₅Ni₀.₅]₂₀Al₁₄ alloy is very near to a pseudo-ternary eutectic. When the cooling rate is higher than 450 K/s, fully amorphous can be formed; when the cooling rate is within 15 K/s to 450 K/s, the alloy has a microstructure of dendrite plus amorphous, when the cooling rate is within 12 K/s to 1.5 K/s, the microstructures of the alloy are dendrite plus eutectic, and when the cooling rate is lower than 0.12 K/s, the morphology of the alloy is eutectic microstructure. The off eutectic alloy has better glass forming ability, the best glass forming alloy obtained at La₆₂[Cu₀.₅Ni₀.₅>]₂₄Al₁₄ along the composition line of La₈₆₋x[Cu₀.₅Ni₀.₅]xAl₁₄. It has a potential to form bulk metallic glassy rod samples with diameter larger than 12 mm. / Singapore-MIT Alliance (SMA)
| Identifer | oai:union.ndltd.org:MIT/oai:dspace.mit.edu:1721.1/3721 |
| Date | 01 1900 |
| Creators | Zhang, Yong, Tan, Hao, Li, Yi |
| Source Sets | M.I.T. Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Article |
| Format | 3165201 bytes, application/pdf |
| Relation | Advanced Materials for Micro- and Nano-Systems (AMMNS); |
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