简介：AnoverlaycoatingmaterialwasdepositedonasinglecrystalsuperalloySRR99bylasercladding.Themicrostructureandoxidationbehaviorofthiscoatingwasinvestigatedthroughscanningelectronmicroscopy(SEM)andX-raydiffraction(XRD).Theresultsindicatedthatalthoughthecompositionofthecoatingwaschosenbasedontheγ'compositioninReneN5superalloy,theprimarysolidificationphaseofthiscoatingduringlasercladdingwasγ-Ni.Furthermore,underthelasercladdingcondition,fineparalleldendritesgrewepitaxiallyinthecoatingfromthesubstrate,indicatingthesinglecrystalstructureofthesubstratewasreproduced.WhenthesinglecrystalMCrAlYcoatingwasoxidizedat1000,bothB-AI2O3and(Y-Al2O3formedduringinitialoxidationprocess.Astheoxidationtimeproceeded,thepreseneeof0-Al2O3facilitatedtheformationofNiAl2O4spineloxide.Oncethespinelwasobserved,itflourishedandinducedsomeporosityinthescale.Whenthescalethicknessincreasedto6-7μm,largeareaspallationofthescalebegan.