A transmission electron microscopy study of precipitate phases that form during operation in a heat exchanger alloy

Precipitation behavior of Al-Si-Cu-Mg(-Fe) alloys by a deformation-semisolid extrusion process

“…It should be noted that this interface is very different from a regular Q' <510>Al interface [12] and from the interface of the Q' phase nucleated on the β-Al5FeSi particle and presented in Fig. 7 (e).…”

“…In (a-b), two Q' phases surrounded by GP like structures are shown. A disordered precipitate containing local Cu sub-unit clusters (the building blocks of Q' and C phases [28]) and units isostructural with the stacking fault reported in [12] is observed in Fig. 5 (c).…”

“…The Cu capsule type [15] refer to Mg-Si-Cu precipitates with high coherency with the Al matrix that are encapsulated by Cu-enriched {200}Al planes (GP-like structures). The Cu walls precipitate refers to a new type found by Marioara et al [12] that contains a Mg-Si core delimited by two Cu walls (enriched {200}Al planes) separated by 6d Al200. In addition, a precipitate consisting of a fragment of β'', segregated Cu atoms at the interfaces and a GP like structure, was observed as shown in Fig.…”

“…An example of periodic arrangement of Cu atomic columns at the interface between the precipitates and the matrix, is identified in Fig. 8 (b) [12,31].…”

“…The GP1 zone in the Al-Cu system is actually an enriched {200}Al plane [8,11] and will be referred to as either 'GP zone' or 'enriched {200}Al plane', or 'Cu wall' in this paper. The GP2 zone is also called θ'' and consists of two enriched {200}Al planes separated by 4dAl200 [12].…”