High throughput determination of creep behavior of additively manufactured AlSi10Mg alloy

Abstract

Power-law creep behavior of laser powder bed fusion (LPBF) AlSi10Mg alloy is evaluated at 250 °C under uniaxial and bending test conditions. Uniaxial tests are performed in both tension and compression, and the cantilever samples are tested using digital image correlation (DIC)-augmented-bending test methodology, which is a way of establishing creep parameters in high throughput fashion. In each test condition, the applied normal stress is along the transverse direction relative to the build direction. The creep response of the alloy exhibits a tension-compression symmetry in terms of the steady-state and minimum creep rates. Correlations of uniaxial and high throughput bending creep tests reveal an excellent correspondence, thereby establishing the viability of evaluating creep behavior via bending, as a first of its kind, for additively manufactured Al alloys. Detailed electron microscopy of the crept specimens revealed the stability of microstructure during the prolonged exposures up to 500 h (during uniaxial creep) and the pinning of dislocations by intra-granular Si (20–50 nm) particles. A detailed discussion on the structure-property relationships is provided.