Characterization of AZ31B wrought magnesium alloy joints welded by high power fiber laser

► Accepted joints of AZ31B Mg alloy are produced by high power fiber laser. ► Optimal welding parameters are summarized by experimental observations. ► Obvious hexagonal dendrites are observed in the fusion zone. ► The joints are stronger than base metal as the heat input is lower than 48 J/mm. ► Pore formation mechanism of welded joints is discussed and summarized.