The thermodynamics of and strengthening due to co-clusters: general theory and application to the case of Al-Cu-Mg alloys
Starink, M.J. and Wang, S.C. (2009) The thermodynamics of and strengthening due to co-clusters: general theory and application to the case of Al-Cu-Mg alloys. Acta Materialia, 57, 2376-2389. (doi:10.1016/j.actamat.2009.01.021).
Co-clusters in ternary or higher order metallic alloys are metastable structures involving two or more distinct alloying atoms that retain the structure of the host lattice. A thermodynamic model based on a single interaction energy of dissimilar nearest neighbour alloying elements is presented, and a model for the strengthening due to these co-cluster dimers is derived. The model includes a new treatment of (short-) order strengthening relevant to these co-clusters and further encompasses modulus hardening and chemical hardening. The models are tested against data on a wide range of Al-Cu-Mg alloys treated at temperatures between 20 and 220ºC. Both quantitative calorimetry data on the enthalpy change due to co-cluster formation and strengthening due to co-clusters is predicted well. It is shown that in general (short-range) order strengthening will be the main strengthening mechanism.
|Keywords:||co-clusters, cosegregation, calorimetry, enthalpy, entropy, free energy, strengthening, modulus hardening, chemical hardening, guinier-preston, GPB, 2024, Al-Cu-Mg, Al-Mg-Si, co-segregation|
|Subjects:||T Technology > TN Mining engineering. Metallurgy|
|Divisions:||University Structure - Pre August 2011 > School of Engineering Sciences > Engineering Materials & Surface Engineering
|Date Deposited:||07 Nov 2008|
|Last Modified:||08 Jun 2012 12:26|
|Contributors:||Starink, M.J. (Author)
Wang, S.C. (Author)
|RDF:||RDF+N-Triples, RDF+N3, RDF+XML, Browse.|
Actions (login required)