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• The crack-front plastic zone evolution of three aluminum alloys under the single overload with two overload ratios was traced using DIC technique. • Crack closure phenomenon was directly observed by using in-situ SEM testing. • The crack closure effect based on Paris-type bi-linear relation can well interpret the post-overload crack growth behavior. The dominant role of crack-front plasticity on crack growth retardation is verified. • A modified Willenborg model considering plastic zone shape effect and residual stress distribution was proposed. Fatigue crack growth behaviors of three aluminum alloys under single overload are investigated by in-situ optical microscopy testing and in-situ SEM testing. The results show that the shape effect of overload-induced plastic zone leads to a larger crack growth retardation range than that assumed in Willenborg model. Besides, the crack closure effect based on general form of Paris law cannot correlate the post-overload crack growth, but a bi-linear form fit the measured effective stress intensity factor behavior well. Moreover, the crack-front plasticity effected range can match the retardation extent. A modified Willenborg model is proposed to predict crack growth retardation. [ABSTRACT FROM AUTHOR]