Plasma sprayed and laser engraved field electron emitters

• Published in: Surface & coatings technology Vol. 165; no. 2; pp. 211 - 215
• Main Authors: Znamirowski, Z., Czarczynski, W., Le Maguer, A., Pawlowski, L.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 10.02.2003; Elsevier
• Subjects: Applied sciences; Cr 2O 3 coatings; Exact sciences and technology; Field emission surfaces; Laser engraving; Metals. Metallurgy; Other surface treatments; Plasma spraying; Production techniques; Surface treatment; Laser engraving; Cr 2O 3 coatings; Plasma spraying; Field emission surfaces; Scanning electron microscopy; Chromium oxide; Experimental study; Coatings; Laser beam etching; Surface treatment; Thin film
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/S0257-8972(02)00765-X

Plasma sprayed Cr 2O 3 coatings were engraved with the use of a CO 2 c.w. laser in an installation for production of anilox rolls. The engraved cells had a ‘honeycomb’ geometry with different line densities and depths: 140 lines/cm with 35-μm depth, 180 lines/cm and 200 lines/cm, both 10 μm deep. The engraved surfaces were subsequently PVD coated with a Ti thin film. The microstructure of the coatings was characterized using scanning electron microscopy and optical microscopy. Finally, the measurements of the field emission current were carried out. It was found out that the greatest current was emitted from the surface engraved with the 34-μm deep cells. The emissions spots were presumably small, micrometer sized crystals generated at the solidification of laser molten Cr 2O 3.