Novel approach based on tensile strain hardening analysis to assess the integrity of an Al alloy produced through High-Pressure Die Casting

The analysis of the structural integrity of components in Al alloys produced by High Pressure Die Casting (HPDC) is paramount for identifying a correlation between process-microstructure-mechanical properties, a correlation that allows to classify the quality process parameters, and identify potential application areas. The tensile test represents the simplest method to pursue this aim, and the tensile strain hardening analysis seems to be capable of providing interesting correlations. In fact, an innovative method based on the analysis of strain hardening through the formalism of the constitutive equation of Voce has provided interesting results in other foundry materials, such as spheroidal cast irons. In this work, we report the results of the application of the innovative method to an Al alloy produced by HPDC in two components having two different geometries. One geometry is that of a round tensile specimen, adopted as a reference since it has an "ideal" microstructure according to the PD CEN/TR 16748:2014 standard, and a second one is a real U shape geometry. The innovative procedure has uniquely identified that the Al alloy with "ideal" microstructure has better microstructural integrity of the material from the U geometry casting, demonstrating that the innovative procedure can also be used successfully for Al alloys produced by HPDC.