Some Properties of Platinum and Palladium Modified Aluminide Coatings Deposited by CVD Method on Nickel-Base Superalloys

J. of Materi Eng and Perform

Kocurek

Pytel

et al. 2016

Self Cite

Two aluminide layers (additive and interdiffusion) were deposited on a turbine blade made of _ ZS6K superalloy by means of VPA and CVD methods. The additive and interdiffusion layers obtained by the VPA method consist of the NiAl phase and some carbides, while the additive layer deposited by the CVD method consists of the NiAl phase only. The residual stresses in the aluminide coating at the lock, suction side, and pressure side of the blade were tensile. The aluminide coating deposited by the CVD method has an oxidation resistance about 7 times better than that deposited by the VPA method. Al 2 O 3 + HfO 2 + NiAl 2 O 4 phases were revealed on the surface of the aluminide coating deposited by the VPA method after 240 h oxidation. Al 2 O 3 + TiO 2 oxides were found on the surface of the aluminide coating deposited by the CVD method after 240 h oxidation. Increasing the time of oxidation from 240 to 720 h led to the formation of the NiO oxide on the surface of the coating deposited by the VPA method. Al 2 O 3 oxide is still visible on the surface of the coating deposited by the CVD method. The residual stresses in the aluminide coating after 30 cycles of oxidation at the lock, suction side and pressure side of the turbine blade are compressive.

Section: Methodsmentioning

confidence: 99%

Oxidation Resistance of Turbine Blades Made of ŻS6K Superalloy after Aluminizing by Low-Activity CVD and VPA Methods

J. of Materi Eng and Perform

Kocurek

Pytel

et al. 2016

Self Cite

“…Standard layered coating system consists typically of 200‐μm thick partially stabilized zirconia top layer, for example, yttria‐stabilized zirconia (YSZ) on the top of a substrate of a nickel superalloy and about 100‐μm thick bond‐coat, type MCrAlY (Torigoe et al ., ; Moskal et al. , ; Goral et al ., ) or aluminide coatings (Zagula‐Yavorska et al ., ).…”

Section: Introductionmentioning

confidence: 99%

“…The CMSX 4 Ni-based superalloy is preferentially used for the hot stage components in industrial gas turbines including parts most exposed to thermal and mechanical stresses like turbine blades (Fullagar et al, 1996;Harada, 2003;Zagula-Yavorska et al 2012;Murr, 2015). The latter are exposed to an extremely corrosive environment and the high-temperature degradation (oxidation and corrosion).…”

Section: Introductionmentioning

confidence: 99%

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Microstructure and oxidation behaviour investigation of rhodium modified aluminide coating deposited on CMSX 4 superalloy

Morgiel²,

Romanowska

et al. 2015

Journal of Microscopy

The CMSX 4 superalloy was coated with rhodium 0.5-μm thick layer and next aluminized by the CVD method. The coating consisted of two layers: the additive and the interdiffusion one. The outward diffusion of nickel from the substrate turned out to be a coating growth dominating factor. The additive layer consists of the β-NiAl phase, whereas the interdiffusion layer consists of the β-NiAl phase with precipitates of σ and μ phases. Rhodium has dissolved in the coating up to the same level in the matrix and in the precipitates. The oxidation test proved that the rhodium modified aluminide coating showed about twice better oxidation resistance than the nonmodified one.

“…Two of them are: the electron beam physical vapor deposition (EB-PVD) [16,17] and the chemical vapor deposition (CVD) methods [18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Zirconium Modified Aluminide Coatings Obtained by the CVD and PVD Methods

Romanowska¹,

Sieniawski³

et al. 2013

OJMetal

The paper presents the comparison of the structures of the zirconium modified aluminide coatings deposited on pure nickel by the CVD and PVD methods. In the CVD process, zirconium was deposited from the ZrCl 3 gas phase at the 1000˚C. Zirconium thin layer (1 or 7 μm thick) and aluminum thin layer (1.0, 0.7 or 0.5 μm thick) were deposited by the EB-PVD method. Deposition velocity was about 1 m/min. The layers obtained by the Electron Beam Evaporation method were subjected to diffusion treatment for 2 h in the argon atmosphere. The obtained coatings were examined by the use of an optical microscope (microstructure and coating thickness) a scanning electron microscope (chemical composition on the cross-section of the modified aluminide coating) and XRD phase analysis. Microstructures and phase compositions of coatings obtained by different methods differ significantly. NiAl(Zr), Ni 3 Al and Ni(Al) phases were found in the CVD aluminide coatings, whereas Ni 5 Zr, Ni 7 Zr 2 and γNi(Al,Zr) were observed in coatings obtained by the PVD method. The results indicate that the microstructure of the coating is strongly influenced by the method of manufacturing.