1 School of Materials Science and Engineering, Beihang University, Beijing 100191, China 2 School of Material Science and Engineering, Nanchang Hangkong University, Nanchang 330063, Jiangxi, China 3 School of Material Science and Engineering, Hunan University, Changsha 410082, Hunan, China
Cyclic oxidation behavior of NiCoCrAlY/YSZ@Ni composite coatings fabricated by laser cladding
1 School of Materials Science and Engineering, Beihang University, Beijing 100191, China 2 School of Material Science and Engineering, Nanchang Hangkong University, Nanchang 330063, Jiangxi, China 3 School of Material Science and Engineering, Hunan University, Changsha 410082, Hunan, China
Composite coating on GH4169 alloy is prepared by laser cladding yttria-stabilized zirconia (YSZ)@Ni core–shell powders mixed with NiCoCrAlY alloy powders. The cyclic oxidation behavior of the coatings, especially the growth process of the oxide layer, is investigated based on experimental research and first-principle calculations. The results indicate that the oxidation resistance of coated GH4169 alloy is better than that of uncoated GH4169 alloy. The coating has three layers: a cellular dendrite outer layer, a planar YSZ interlayer, and an inner layer composed of Cr2O3 formed during laser cladding. After oxidation at 1000 and 1050 °C, as the oxidation time increases, the cellular dendrite outer layer becomes thicker, and the planar yttria-stabilized zirconia interlayer becomes thinner. Between the planar interlayer and Cr2O3 inner layer, an Al2O3 layer formed. Notably, cracks formed in the interface of Al2O3/Cr2O3 owing to their weak interface strength, which led to the failure of the composite coating.
Composite coating on GH4169 alloy is prepared by laser cladding yttria-stabilized zirconia (YSZ)@Ni core–shell powders mixed with NiCoCrAlY alloy powders. The cyclic oxidation behavior of the coatings, especially the growth process of the oxide layer, is investigated based on experimental research and first-principle calculations. The results indicate that the oxidation resistance of coated GH4169 alloy is better than that of uncoated GH4169 alloy. The coating has three layers: a cellular dendrite outer layer, a planar YSZ interlayer, and an inner layer composed of Cr2O3 formed during laser cladding. After oxidation at 1000 and 1050 °C, as the oxidation time increases, the cellular dendrite outer layer becomes thicker, and the planar yttria-stabilized zirconia interlayer becomes thinner. Between the planar interlayer and Cr2O3 inner layer, an Al2O3 layer formed. Notably, cracks formed in the interface of Al2O3/Cr2O3 owing to their weak interface strength, which led to the failure of the composite coating.
Hai-zhong Zheng,Pei-feng Zhou,Gui-fa Li, et al. Cyclic oxidation behavior of NiCoCrAlY/YSZ@Ni composite coatings fabricated by laser cladding[J]. Journal of Iron and Steel Research International, 2020, 27(10): 1226-1235.
2020, Vol. 27 
