In:
Scientific Reports, Springer Science and Business Media LLC, Vol. 8, No. 1 ( 2018-11-09)
Abstract:
Atomic scale characterization of fine precipitates in an under-aged Cu added Al-Mg-Si alloy was carried out by combination of atomically-resolved annular dark-field scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. Two types of precipitates were observed in the alloy. In the case of ordered β” precipitates, β” was proposed as Mg 5-x Al 2+x Si 4 (x ≈ 1) with solute Cu atoms replacing Al site of β” precipitate. In the case of disordered precipitates, the precipitates were found to consist of β” sub-unit cells, three-fold symmetric structure without Cu atoms, Cu containing structures termed as “Cu sub-unit cluster”, and Q’ sub-unit cells. Among these structures, the morphologies of three-fold symmetric structure without Cu atoms, Cu sub-unit cluster, and Q’ sub-unit cell were almost the same, so that these structures should be the clusters of Q’ phase. Since the areal density, length and diameter of precipitates were almost equal between Cu free Al-Mg-Si alloy and Cu added Al-Mg-Si alloy, the increase of hardness by Cu addition should be due to the precipitation of Cu related precipitates, such as Cu sub-unit clusters and Q’ sub-unit cells.
Type of Medium:
Online Resource
ISSN:
2045-2322
DOI:
10.1038/s41598-018-35134-8
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2018
detail.hit.zdb_id:
2615211-3
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