Electrical resistometry study of an AlMgSi alloy under artificial aging

The artificial aging of an AlMgSi commercial alloy was studied by electrical resistometry measurements. A laboratory-made experimental arrangement was designed in order to avoid natural aging prior to artificial aging. The electrical resistometry evolution was compared to Vickers microhardness determinations, and correlated with the precipitation sequence. The temporal evolution of β″ relative volume fraction is described by a normalized resistance evolution by means of a Johnson–Mehl–Avrami type equation. The activation energy is in good agreement with that obtained from differential scanning calorimetric experiments.

► The β″-AlMgSi precipitation was studied by electrical resistometry determinations.
► A laboratory-made experimental arrangement was specially designed.
► The electrical resistometry and microhardness evolution are compared.
► A quantitative analysis is proposed for monitoring the artificial aging process.
► The obtained β″ activation energy agrees with that obtained by DSC.