Open AccessHardening and precipitation of a commercial 6061 Al alloy during natural and artificial ageing
Author(s) -
Y. Chen,
Baokun Lu,
H. A. Zhang
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/770/1/012065
Subject(s) - alloy , precipitation hardening , materials science , ageing , quenching (fluorescence) , precipitation , hardening (computing) , vickers hardness test , scanning electron microscope , metallurgy , transmission electron microscopy , composite material , microstructure , fluorescence , nanotechnology , genetics , physics , layer (electronics) , quantum mechanics , meteorology , biology
In this study, the precipitation and hardening of a commercial 6061 Al alloy during the combined natural and artificial ageing are analyzed, in order to maximize the alloy hardness by adjusting ageing time and temperature. The samples were solution-treated at 540°C for 2 hours, followed by water quenching. An artificial ageing was performed at 180, 200, and 220°C during a period from 2 min to 12 h. Natural ageing at room temperature during 12 h was performed simultaneously with the artificial one at different elevated temperatures. The Vickers hardness values of solution-treated and aged samples were measured. Precipitates were characterized via the X-ray diffraction and scanning transmission electron microscopy equipped with the energy dispersive X-ray spectroscopy. The highest hardness values were exhibited by samples that were naturally aged for 12 hours and artificially aged for 24 hours at 200 and 220°C. The hardness improvement was found to be controlled by the formation of β” phases before the peak ageing.