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2540 |
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Development of nanostructured FeAl intermetallics by annealing of cold sprayed precursor deposit |
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Hongtao Wang / Jiangxi Engineering Research Center for Materials Surface Remanufacturing
School of Mechanical and Materials Engineering
Jiujiang University, Jiujiang, Jiangxi, P.R.China Chang-Jiu Li / State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University,, P.R.China Gang-Chang Ji/ JiuJiang Key Laboratory for Green Remanufacturing, Jiujiang University., P.R.China Guan-Jun Yang/ State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, P.R.China |
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FeAl Intermetallic compounds have excellent wear resistance and high temperature oxidation resistances. It is difficult to deposit dense intermetallic compound coatings by directly cold spraying of the compound feedstock powders due to their intrinsic low temperature brittleness. In the present study, the nanostructured FeAl coating was produced by cold spraying of mechanically alloyed Fe(Al) solid solution alloy powder and followed by annealing treatment of cold-sprayed precursor deposit. The influence of post-spray annealing treatment on the microstructure and microhardness evolution of nanostructured cold-sprayed FeAl coating was investigated. The results showed that transformation of Fe(Al) solid solution into FeAl intermetallics occurred at 500oC, with the mean grain size about 37nm. The heterogeneous feature in the as-sprayed coating was evidently modified after annealing at 650oC and the particles interfaces completely disappeared with rising annealing temperature to 950oC. Minimal grain growth of the FeAl phase was observed accompanying the microstructure improvement of the cold-sprayed FeAl deposit at the elevated treatment temperatures. The microhardness of the cold-sprayed FeAl deposit changed little when annealed at temperatures of up to 800oC. |