Abstract
The linear-chain distribution of precipitates, resembling the characteristic features of bamboo, in a Mg–3 wt.% Nd alloy, aged at 250 C for 10 h, has been examined using high-angle annular dark-field scanning transmission electron microscopy. The configuration consists of bamboo trunks of b1 variants and trunk connections of a hitherto unreported phase designated b2 in this work. The b2 phase has a hexagonal lattice (space group P6, a = 0.523 nm and c = 0.963 nm), and its orientation relationship with the Mg matrix phase is such that h1120ib2 //[0001]a and f1 1 0 0gb2 //f1100ga. The b2 phase is metastable, but it is induced to form and is stabilized by the stress fields of the two adjacent b1 particles. The b2 particle either has a substructure of ð0 0 0 1Þb2 planar faults, or is free of the planar faults, depending on whether the two b1 precipitates connecting it are of the same variant or not. A minor fraction of bamboos also have leaf-like b1 particles attached to the connection point of the bamboo trunks. The formation of the leaf-like particles is analyzed by nteraction energy calculation and phase-field simulation.
Original language | English |
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Pages (from-to) | 239 - 247 |
Number of pages | 9 |
Journal | Acta Materialia |
Volume | 83 |
DOIs | |
Publication status | Published - 2015 |
Equipment
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Monash Centre for Electron Microscopy (MCEM)
Sorrell, F. (Manager) & Miller, P. (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility