Abstract: The surfaces of 6061 Al-alloy,an advanced material in fabrication of heating,ventilation and air conditioning(HAVC) facilities,were modified with Ni,CoCrTaAlY,and poly-ethylene oxide(PEO) multilayered coatings,deposited by successive cold-spray in air and by plasma-spray in argon atmosphere.The influence of the deposition conditions on the microstructures,oxidation/corrosion/erosion resistances and interfacial adhesion was investigated with X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy and thermal shock/scour tests for optimization of the synthesis conditions.The preliminary results show that depending on the Ni-transition layer,the cold spray is capable of depositing fairly uniform,compact Ni,CoCrTaAlY and PEO multilayered coatings with strong interfacial adhesion,and significantly improving the resistances of high-temperature oxidation/corrosion/erosion of 6061 Al-alloy.When it comes to surface modification of 6061 Al-alloy,we suggest that the results we reported may be of some technological interest in HAVC industry.