کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1658549 | 1517677 | 2011 | 6 صفحه PDF | دانلود رایگان |
NiCoCrAlY coatings were prepared on superalloy K417G using arc ion plating (AIP), then some specimens coated with NiCoCrAlY were aluminized using a pack cementation method. The high temperature oxidation and hot corrosion behavior of the ordinary and the aluminized NiCoCrAlY coatings were studied. The results indicated that α-Al2O3 scales grew on both coatings during oxidation at 1000 °C and 1100 °C in air, and the aluminized NiCoCrAlY coating always showed lower oxidation rates and lower degradation rates. The hot corrosion tests were carried out by applying salt films of 25 wt.% K2SO4 + 75 wt.% Na2SO4 mixture on the specimens and exposing in air at 900 °C. The aluminized NiCoCrAlY coating showed a longer lifetime by forming a continuous Al2O3 scale. But, cracks and spallation of the oxide scales occurred on the ordinary NiCoCrAlY coating after 80 h.
Research highlights
► AIP NiCoCrAlY coating were modified by aluminizing using pack cementation process.
► Al2O3 scales formed on modified coatings during oxidation at both 1000 °C and 1100 °C.
► The modified coatings obtained a much longer lifetime during hot corrosion exposure.
Journal: Surface and Coatings Technology - Volume 205, Issues 21–22, 25 August 2011, Pages 5053–5058