  Zn-Al-Mg coatings are characterized by a complex microstructure with
dendritic and eutectic phases. This heterogeneous phase distribution
contributes to multiple deformation and damage mechanisms. The presence of
brittle phases promotes crack initiation and propagation. This study reveals a
new deformation and damage mechanism of a Zn-Al-Mg coating, where twinning can
induce crack initiation in the eutectic region. The chronology of different
events leading to crack initiation and propagation is clearly established by
in-situ tensile testing in a scanning electron microscope, which helps to
establish a detailed characterization of the mechanical behavior of the
coating.
