A new quaternary phase observed in a laser treated Zn–Al–Mg–Si coating

•A new quaternary phase was discovered in laser treated Zn–55Al–2Mg–1Si coating.•The crystal structure of the new phase was determined by TEM.•The new phase was not a metastable phase induced by the rapid cooling of the laser treatment.•Laser treatment led to not only a much finer microstructure but also changes of phases in the interdendritic areas of the coating. The microstructure of laser resurfaced Zn–55Al–2Mg–1.5Si coating produced on a hot-dip simulator was characterised by transmission electron microscopy. A new quaternary phase was observed and its crystal structure was determined by electron diffraction.