Influence of aging temperature and aging time on the mechanical property and microstructure during precipitation hardening of Al 6061 alloy

The heat treatable aluminium alloys can be strengthened by precipitation of extremely small uniformly dispersed particles of a second phase within the original matrix. In this study, artificial aging behavior of Al 6061 alloy is investigated in the temperature range 100-200�C using Scanning Electron Microscope and Transmission Electron Microscope. Attempt has also been made to correlate its mechanical properties with that of corresponding microstructure particularly size, shape and distribution of fine precipitates during aging. It is found that after aging at 100�C highest strength can be obtained at longer duration of aging. This has been supported by Scanning Electron Microscope and Transmission Electron Microscope micrographs of the same condition. For aging at lower temperature gives more number of fine precipitates. This is the reason for getting higher strength as small precipitates with more numbers give more resistance of dislocation movements resulting higher strength.