TY - JOUR
T1 - Precipitation processes during the early stages of ageing in Al-Cu-Mg alloys
AU - Ringer, S. P.
AU - Hono, K.
AU - Polmear, I. J.
AU - Sakurai, T.
N1 - Funding Information:
S.P.R. wishes to acknowledge the support of the Japan Society for the Promotion of Science for provision of a Postdoctoral Research Fellowship.
PY - 1996/3
Y1 - 1996/3
N2 - Atom probe field ion microscopy (APFIM), transmission electron microscopy (TEM), and microbeam electron diffraction have been used to study the early stages of precipitation in an Al-1.1Cu-1.7Mg (at%) alloy. This alloy exhibits a large and rapid hardening reaction upon ageing for as short as 60 s at temperatures higher than 130 °C. Results from APFIM suggest that the formation of Cu-Mg co-clusters, not resolved in TEM, is responsible for the rapid hardening reaction. A period of constant hardness follows the rapid initial reaction, during which the clusters develop into ultra fine rod-like precipitates, considered to be GPB zones and precipitation of the S phase (Al 2 CuMg) occurs heterogeneously on dislocations. Like the initial clusters, the GPB zones were found to be rich in Cu and Mg. Peak hardness was associated with the further dispersion of S precipitates in the matrix and further growth of GPB zones, suggesting the following precipitation sequence: solid solution → pre-precipitate stage → GPB zones + S → S.
AB - Atom probe field ion microscopy (APFIM), transmission electron microscopy (TEM), and microbeam electron diffraction have been used to study the early stages of precipitation in an Al-1.1Cu-1.7Mg (at%) alloy. This alloy exhibits a large and rapid hardening reaction upon ageing for as short as 60 s at temperatures higher than 130 °C. Results from APFIM suggest that the formation of Cu-Mg co-clusters, not resolved in TEM, is responsible for the rapid hardening reaction. A period of constant hardness follows the rapid initial reaction, during which the clusters develop into ultra fine rod-like precipitates, considered to be GPB zones and precipitation of the S phase (Al 2 CuMg) occurs heterogeneously on dislocations. Like the initial clusters, the GPB zones were found to be rich in Cu and Mg. Peak hardness was associated with the further dispersion of S precipitates in the matrix and further growth of GPB zones, suggesting the following precipitation sequence: solid solution → pre-precipitate stage → GPB zones + S → S.
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U2 - 10.1016/0169-4332(95)00383-5
DO - 10.1016/0169-4332(95)00383-5
M3 - Article
AN - SCOPUS:0030562765
VL - 94-95
SP - 253
EP - 260
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
ER -