Failure analysis of fatigue crack propagation in specimens of AlSi10Mg aluminum alloy produced by L-PBF: Effect of different heat treatments

Fatigue crack growth behavior of AlSi10Mg aluminum alloy processed by laser powder bed fusion (L-PBF) was studied for three material conditions: as-built, stress relieved and hot isostatic pressed. An improvement in the fatigue crack growth resistance was found for the heat-treated conditions which was attributed to the residual stress relief induced by the heat treatments. The stress ratio did not affect the fatigue crack growth in regime II which was explained by the absence of crack closure. Fatigue crack growth rates were predicted using a model based on the cyclic plasticity of the tested aluminum alloy. The proposed model agreed well with the experimental results.