Abstract
Microstructure evolutions were experimentally studied as a function of growth velocity and alloy composition in LaxAl14(Cu, Ni)86 - x alloys (x = 57-74). The composition-velocity ranges were determined for the formation of eutectic, amorphous, eutectic + compound, amorphous + dendrite, and eutectic + dendrite. A skewed eutectic coupled zone was found towards the compound phase. A composite structure composed of ductile La dendrites in a matrix of either eutectic or amorphous phase can be produced in hypoeutectic alloys. Compressive tests were performed on amorphous/dendrite and eutectic/dendrite composites. As the volume fraction of dendrites increases, fracture strength linearly decreases and obeys a rule-of-mixtures relationship, whereas plastic strain exhibits an exponential increase. Optimised mechanical properties can be realized through both alloy composition design and well-controlled solidification processing.
Original language | English |
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Pages (from-to) | 2607-2616 |
Number of pages | 10 |
Journal | Acta Materialia |
Volume | 53 |
Issue number | 9 |
DOIs | |
Publication status | Published - May 2005 |
Externally published | Yes |
Keywords
- Bridgman solidification
- Bulk metallic glass
- Composite
- Eutectic
- La based alloy