Fluoride-mediated corrosion mechanism of atmospheric-plasma-sprayed yttrium–aluminium garnet ceramic coatings. Issue 13 (October 2022)

• Record Type: Journal Article
• Authors: Huang, Biao; Wang, Jun; Tang, Zheng-hua; Li, Wei-dong; Zhu, Wen-jian; Gu, Ren-Bao
• Is Part Of: Journal of the European Ceramic Society. Volume 42:Issue 13(2022)
• Page Start: 6146
• Page End: 6158
• Publication Date: 2022-10
• Subjects: YAG Yttrium–aluminium garnet -- APS atmospheric plasma spraying -- NLPM normal litres per minute -- RF radiofrequency -- XRD X-ray diffraction -- SEM scanning electron microscopy -- AFM atomic force microscopy -- XPS X-ray photoelectron spectroscopy -- FM full melting -- PM partial melting -- YOF yttrium oxyfluoride -- sccm standard cubic centimetres per minute -- CCP capacitively coupled plasma -- TEM transmission electron microscopy -- FIB-SEM focused ion beam scanning electron microscopy -- SAED selected area electron diffraction; Yttrium–aluminium garnet (YAG) -- Atmospheric plasma spraying -- Yttrium oxyfluoride (YOF) -- Fungal etching -- Fluorocarbon plasma; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2022.06.012
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Atmospheric-plasma-sprayed yttrium–aluminium garnet coatings were exposed to Ar/O2 /CF4 plasma in a capacitively coupled plasma etching machine to induce fluoride-mediated corrosion and to elucidate the mechanism by which fluoride-containing plasma etched the coatings. In the first corrosion stage, the fully melted region, non-fused particles, and pore edges were etched; the etching products consisted of a series of aggregated and stacked fan-shaped particles, among which the non-fused particles exhibited the most severe etching. With prolonged etching, various coating surface regions gradually fused and smoothened, while the surface roughness decreased. Corrosion products Al2 O3 AlF3, YOF, and YF3 were also formed on the coating surface, and the etching product evolution looked like the fungus Ganoderma lucidum ; hence, the name 'fungal etching'. The study findings will further the development of ceramic coatings resistant to corrosion by halogen plasma for application to semi-conductor processing equipment. Highlights: APS YAG ceramic coatings were etched with Ar/CF4 /O2 plasma. Etching products appeared on semi-molten particle surfaces/in pores/at FM zone edge. Small fan-shaped etching traces evolved into large fungal-fruiting-body-type traces. Etching products accumulated on coating surface were removed by ion bombardment. Ion bombardment homogenised FM heights/integrated FM zones/smoothed coating surface.