Assessment of decomposition products in an Al–Mg–Si alloy by instrumented micro-indentation

Strain rate sensitivity measurements were made at 299 K by displacement controlled micro-indentation of an Al–Mg–Si alloy undergoing natural and artificial ageing at 299 and 463 K, respectively. The measured apparent activation volumes and apparent activation work are shown to discriminate differences in microstructural decomposition products expected for each ageing treatment that are not tractable from hardness measurements alone.