Experimental and thermodynamic investigations into the microstructure of laser clad Al-Si coatings on AZ91D alloys

► A dense, crack and porous free coating was fabricated on AZ91D alloy by laser cladding. ► The microstructure and phase of the bottom layer and the upper layer appear to have a great difference. ► The phase fraction, composition and solidification were calculated by Thermo-Calc. ► Calculation results obtained by Thermo-Calc agree well with the ones from the experiment.