Age-hardening of Al-Mg alloys with additions of Zn, Cu and AgWednesday (06.11.2019) 17:40 - 18:00 Part of:
The age-hardening response of an Al-Mg alloy with additions of copper, zinc and silver has been investigated in this research. Single-step artificial aging of alloys with the addition of Zn and gradual increasing Cu content showed a distinct age-hardening potential with a maximum hardness of 130 HBW in the investigated time range. Additional doping with silver results in a shift of the hardening onset to earlier aging times and an even higher hardness up to 165 HBW. Moreover, application of a pre-aging step on non-Ag-doped alloys leads to a similar boosting effect on the hardening kinetics as observed in the Ag-modified and single-step aged alloys. For the alloys containing Zn, Cu and Ag the two-step artificial aging strategy exhibits a further acceleration of the hardening and an increase in peak hardness. Independent of the heat treatment, alloys containing the highest amount of Cu show the highest hardening response. According to TEM investigations the increased hardening response and peak hardness is related to significant alterations in the microstructure due to Ag addition and adapted heat treatment strategy.