Adil Ashary - Academia.edu (original) (raw)
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Papers by Adil Ashary
Surface and Coatings Technology, 1991
Surface and Coatings Technology, 1989
Surface and Coatings Technology, 1990
Abstract The corrosion resistances of 13 alloys including several 300 series stainless steels, wi... more Abstract The corrosion resistances of 13 alloys including several 300 series stainless steels, with and without a chromium oxide coating deposited by plasma spray, were evaluated in chloride-containing aqueous environments. Short-term electrochemical tests were used to evaluate the pitting corrosion resistance of bare alloys and the crevice corrosion resistance of the alloys with the coating. Salt spray immersion tests were conducted to evaluate the long-term corrosion behavior. The coated samples used in this study were not sealed. Results of the short-term electrochemical corrosion tests were found to be very consistent with the long-term corrosion data. All 300 series stainless steels together with several other alloys were found to be susceptible to pitting and crevice corrosion. Stainless steels such as Ferralium 255 R , 20Mo-6™ and 7-Mo Plus™ were found to have good resistance to crevice corrosion. (Ferralium 255 is a registered trademark of Haynes International, Inc. 20Mo-6 and 7-Mo Plus are trademarks of Carpenter Technology, Inc.) The Inconel 625 (IN 625) and Ti-6Al-4V alloys were found to have the highest corrosion resistances of all the alloys evaluated. The chromium oxide coating did not show any significant corrosion.
Journal of Thermal Spray Technology, 2008
The most advanced thermal barrier coating (TBC) systems for aircraft engine and power generation ... more The most advanced thermal barrier coating (TBC) systems for aircraft engine and power generation hot section components consist of electron beam physical vapor deposition (EBPVD) applied yttria-stabilized zirconia and platinum modified diffusion aluminide bond coating. Thermally sprayed ceramic and MCrAlY bond coatings, however, are still used extensively for combustors and power generation blades and vanes. This article highlights the key features of plasma spray and HVOF, diffusion aluminizing, and EBPVD coating processes. The coating characteristics of thermally sprayed MCrAlY bond coat as well as low density and dense vertically cracked (DVC) Zircoat TBC are described. Essential features of a typical EBPVD TBC coating system, consisting of a diffusion aluminide and a columnar TBC, are also presented. The major coating cost elements such as material, equipment and processing are explained for the different technologies, with a performance and cost comparison given for selected examples.
Volume 5: Microturbines and Small Turbomachinery; Oil and Gas Applications, 2009
A new class of corrosion-and creep-resistant austenitic stainless steels has been developed for a... more A new class of corrosion-and creep-resistant austenitic stainless steels has been developed for advanced recuperator applications. The Al and Cr contents have been optimized to maintain a fully austenitic composition for creep strength while allowing the formation of a highly-...
Surface and Coatings Technology, 1991
Surface and Coatings Technology, 1989
Surface and Coatings Technology, 1990
Abstract The corrosion resistances of 13 alloys including several 300 series stainless steels, wi... more Abstract The corrosion resistances of 13 alloys including several 300 series stainless steels, with and without a chromium oxide coating deposited by plasma spray, were evaluated in chloride-containing aqueous environments. Short-term electrochemical tests were used to evaluate the pitting corrosion resistance of bare alloys and the crevice corrosion resistance of the alloys with the coating. Salt spray immersion tests were conducted to evaluate the long-term corrosion behavior. The coated samples used in this study were not sealed. Results of the short-term electrochemical corrosion tests were found to be very consistent with the long-term corrosion data. All 300 series stainless steels together with several other alloys were found to be susceptible to pitting and crevice corrosion. Stainless steels such as Ferralium 255 R , 20Mo-6™ and 7-Mo Plus™ were found to have good resistance to crevice corrosion. (Ferralium 255 is a registered trademark of Haynes International, Inc. 20Mo-6 and 7-Mo Plus are trademarks of Carpenter Technology, Inc.) The Inconel 625 (IN 625) and Ti-6Al-4V alloys were found to have the highest corrosion resistances of all the alloys evaluated. The chromium oxide coating did not show any significant corrosion.
Journal of Thermal Spray Technology, 2008
The most advanced thermal barrier coating (TBC) systems for aircraft engine and power generation ... more The most advanced thermal barrier coating (TBC) systems for aircraft engine and power generation hot section components consist of electron beam physical vapor deposition (EBPVD) applied yttria-stabilized zirconia and platinum modified diffusion aluminide bond coating. Thermally sprayed ceramic and MCrAlY bond coatings, however, are still used extensively for combustors and power generation blades and vanes. This article highlights the key features of plasma spray and HVOF, diffusion aluminizing, and EBPVD coating processes. The coating characteristics of thermally sprayed MCrAlY bond coat as well as low density and dense vertically cracked (DVC) Zircoat TBC are described. Essential features of a typical EBPVD TBC coating system, consisting of a diffusion aluminide and a columnar TBC, are also presented. The major coating cost elements such as material, equipment and processing are explained for the different technologies, with a performance and cost comparison given for selected examples.
Volume 5: Microturbines and Small Turbomachinery; Oil and Gas Applications, 2009
A new class of corrosion-and creep-resistant austenitic stainless steels has been developed for a... more A new class of corrosion-and creep-resistant austenitic stainless steels has been developed for advanced recuperator applications. The Al and Cr contents have been optimized to maintain a fully austenitic composition for creep strength while allowing the formation of a highly-...