Nano Precipitation and Hardening of Die-Quenched 6061 Aluminum Alloy

Abstract

Die quenching is applied to an age-hardenable aluminium alloys to obtain super-saturated solid solution. The application is advantageous because it can reduce number of manufacturing processes, and may increase strength by strain aging. If die quenching is realized in forging as well as sheet forming, it may widen industrial applicability further. In this study, Al-Mg-Si alloy AA6061 8 mm-thick billets were reduced 50% in height without cracks by die-quench forging. Supersaturated solid solution was successfully obtained. The die-quenched specimen shows higher hardness with nano precipitates at shorter aging time than the conventional water-quenched specimen.

Microstructure and Properties of 6 Series Aluminum Alloy Under Different Aging Treatment Systems

“…By coating and baking the formed plate, high hardness and yield strength can be achieved after age hardening, while the plate obtained after solution treatment stagnates at room temperature for some time. The hardening that occurs in the course of natural aging tends to hinder the strengthening effect of artificial aging (simulated paint baking) [6,7]. The typical aging precipitation sequence of 6-series aluminum alloy is: supersaturated solid solution (SSSS)→solute atom segregation zone (G.P.)…”