کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1582403 | 1514873 | 2008 | 8 صفحه PDF | دانلود رایگان |
The effects of annealing on the microstructure of first stage (high-Al activity pack) aluminized coating on Ni–15Cr alloy prepared by pack cementation method were analyzed by transmission electron microscope. The coating consists of a thin layer of γ′-Ni3Al, an interfacial zone of mixed β-NiAl and α-Cr, and a thick outer zone of β-NiAl (A layer) and mixed β-NiAl and α-Cr (B layer). Martensitic transformation was observed in the β-NiAl grains in the interfacial zone. Parallel crystallographic relationship was found at the γ/γ′ interface in the substrate and the α/β interface in the interfacial zone. Cr2Al was found to precipitate in the β-NiAl and α-Cr grains in the B layer of the outer zone. The formation mechanisms of the coating layers, the precipitates, and the observed crystallographic relationships are discussed.
Journal: Materials Science and Engineering: A - Volume 485, Issues 1–2, 25 June 2008, Pages 550–557