Effect of Trace Addition of Sn in Al-Cu Alloy

Tomoyuki Honma; David W. Saxey; Simon P. Ringer

doi:10.4028/www.scientific.net/MSF.519-521.203

Paper Titles

Confirming Computer Calculations of Phase Stability with the Experimental Observations in Automotive Alloy AA6111
p.177

Modeling the Role of Microstructure on Shear Instability with Reference to the Formability of Automotive Aluminium Alloys
p.183

Nucleation-Mediated Structural Refinement and Aluminium Alloy Design
p.191

Vacancy-Solute Interactions in Al-Cu-Mg
p.197

Effect of Trace Addition of Sn in Al-Cu Alloy
p.203

Low Temperature Thermal Stability of Quaternary Al-Li-Cu-Mg Alloys
p.209

Improvement of Bake-Hardening Response of Al-Mg-Cu Alloys by Means of Nanocluster Assist Processing (NCAP) Technique
p.215

HRTEM Study of Precipitates in Al-Mg-Si and Al-Mg-Ge Alloys
p.221

The Effect of Composition and Temperature on the Ageing Response of some Dilute 6xxx Series Alloys
p.227

HomeMaterials Science ForumMaterials Science Forum Vols. 519-521Effect of Trace Addition of Sn in Al-Cu Alloy

Effect of Trace Addition of Sn in Al-Cu Alloy

Abstract:

The trace addition of Sn (0.01 at.%) to an Al-1.7Cu (at.%) alloy has been investigated using atom probe tomography (APT), transmission electron microscopy (TEM) and high resolution transmission electron microscope (HRTEM). We have studied samples in the as-quenched (AQ) condition and following ageing at both 160 and 200 °C for very short ageing times so as to better understand the early stages of the decomposition processes. Our data reveal independent Cu-Cu and Sn-Sn clusters in the AQ condition, though we did not observe Cu-Sn clustering. We observed for the first time that some of these initial Cu-clusters develop into GP zones during subsequent ageing at temperatures as high as 200 °C. The Sn atom clustering results in precipitation of independent 􀀂- Sn particles after aging for 30 sec. The GP zones consequently undergo reversion and this liberates Cu atoms which seem to participate in a cluster-assisted heterogeneous nucleation of the 􀀃􀀂 phase at the interface of the 􀀂-Sn. For ageing at 200 °C, this process is complete within 180 sec.