Deposition Properties of Cold-Sprayed CoNiCrAlY Coatings Prepared with Nitrogen Gas
Thermal sprayed MCrAlY coatings are widely used for gas turbine applications against high-temperature oxidation and corrosion. Oxidation of particles during thermal spraying is inevitable due to its high temperature required to melt the particles. It is the best choice to choose vacuum plasma spraying to prepare MCrAlY coatings, but it is much more expensive than other thermal spray. However, for further improvement of turbine efficiency, dense and stable thick coatings are necessary. Cold spray technology provides a possibility to prepare such high performance MCrAlY coatings due to its high impact velocity of particles and low process temperature, which can avoid thermal residual stress and oxidation. To obtain an applicable MCrAlY coatings, helium is always used as carrier gas with cold spraying. It is very expensive to use helium although helium recycling system adopted, so using nitrogen or compressed air as carrier gas instead of helium provokes many researchers interesting. In this work, CoNiCrAlY coating was deposited by cold spraying methods with nitrogen as carrier and accelerating gas under the temperature of 750℃ and pressure of 4 Mpa. The microstructure of the coating was characterized through surface morphology and cross-sectional microstructure by scanning electron microscopy. The results showed that the coating is deposited through intensive plastic deformation of the spray particles by high speed impact, and very little oxide phenomena discovered in the cold spray process. Micro-hardness is tested using the Digital Vickers Micro-hardness Tester. The results revealed that a compact texture and high micro-hardness CoNiCrAlY coating can be obtained by cold spray with nitrogen gas.
Cold Spray CoNiCrAlY Coating Thermal Spray
HUANG Guo-sheng
State Key Laboratory for Marine Corrosion and Protection,Qingdao 266071,China Luoyang Ship Material Research Institute (LSMRI),Qingdao 266071,China
国际会议
The Fourth Asian Conference on Heat Treatment and Surface Engineering(第四届亚洲热处理及表面工程大会)
北京
英文
574-577
2009-10-27（万方平台首次上网日期，不代表论文的发表时间）