AlSil0Mg alloy produced by Selective Laser Melting: relationships between Vickers microhardness, Rockwell hardness and mechanical properties

Selective Laser Melted Al10SiMg samples were directly aged at different temperatures and times to establish the best mechanical properties for this alloy. The problem of finding meaningful relationships between hardness and tensile strengths has been addressed for materials produced by additive manufacturing technology.Relationships between hardness and yield and ultimate tensile strengths have been calculated by combining Hollomon parameters (the strain hardening exponent 'n' and the strength coefficient 'K') for the Selective Laser Melted Al10SiMg alloy. Firstly, the pre-existing relationships were considered and verified for AlSi10Mg SLMed alloy. Moreover, the relationship derived from ASTM standards and Hollomon parameters were calculated from the engineering stress-strain curves. Afterwards, the measured values of Rockwell hardness (HRF) and Vickers hardness (HV) were related to each other by a simple equation according to theory. The results showed the accuracy of this equation with respect to the theoretical one. Finally, the yield strength, UTS and ultimate strength (sigma(b), in function of strain hardening exponent and natural base e) obtained by different condition of thermal treatments (175 degrees C, 200 degrees C and 225 degrees C for 2h, 4h and 6h) were related to Vickers hardness values.