Application of the jump model to the decomposition of some binary and ternary aluminium alloys

Abstract

In order to get more information from the atomistic point of view about the processes in the early stage of ageing of binary and ternary alloys the jump model proposed by Panseri and Federighi is extended to include diffusion of more than one kind of complex in the matrix. The model is used to explain experimental results on the decomposition of AlZn(6), AlZn(6)–Ge(X), and AlZn(3)–Mg(X) alloys obtained by means of resistivity measurements and investigations of the Young modulus in the early stage of ageing.

A quantitative interpretation of the decomposition kinetics of some AlZnMg alloys

“…I n recent past several papers have been presented by the authors concerning the decomposition behaviour of Al-Zn-Mg alloys in the early stage of decomposition [l to 91. I n the Al-Zn(6 at%)-Mg(X) alloys (concentrations are consistently given in atyo) the times of the appearance of the maximum of resistivity of these ternary alloys t i a x could be described by the so-called extended jump model [3, 7 , 81 (shortly E J M ) using the following premises: is that a t least in the early stage of decomposition the GPZ are mainly formed by the Zn atoms and therefore the (apparent) total number of jumps [7] can be written…”