On macrohardness testing of Al–7 wt.% Si–Mg alloys: II. An evaluation of models for hardness–yield strength relationships

Past efforts to predict hardness–yield strength (YS) relationships in aluminum alloys have been reviewed. Hardness data for Al–7 wt.% Si–Mg alloys with three different Mg levels and artificially aged for different durations have been analyzed for possible hardness–yield strength relationships. All models reported in the literature, except for the one developed by Shabel and Young, have been found to be affected by alloy temper. A new model that is unaffected by alloy temper has been developed that can be used to predict yield stress (YS) of these alloys from multiple hardness readings. These effects, as well as that of microstructure are discussed in the paper.