Preparation and Characterization of Chemically Vapor Deposited ZrO₂ Coating on Nickel and Ceramic Fiber Substrates

Abstract

Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6063 tion. With this heating method, the center portion of the reaction Monoclinic ZrO 2 was deposited on several metallic and chamber (ϳ5 cm length) could be rapidly heated up to a peak ceramic substrates by reacting ZrCl 4 , CO 2 , and H 2 at temtemperature of 1100ЊC with a relatively uniform temperature peratures of 800؇ to 1050؇C. Ni substrates reacted signifidistribution (within Ϯ25ЊC). A K-type thermocouple was used to cantly in the ZrO 2 coating environment since the coating measure the temperature at the center region of the reactor. was porous and contained a considerable amount of Ni. InThe flow rates of Ar, Cl 2 , CO 2 , and H 2 (99.995%, Alphagaz, contrast, the coating deposited on SiC and aluminoborosiliMorrisville, PA) were controlled using mass flow controllers cate fibers was highly crystalline, faceted, and dense without (1259B, MKS, Andover, MA). The pressure of the reactor was any apparent interaction with the substrate materials.controlled using a mechanical vacuum pump and a solenoid flow valve (248A, MKS) interfaced with a pressure controller (250B,

ZrO2 Nanopowders Prepared by Low‐Temperature Vapor‐Phase Hydrolysis

“…For example, zirconia coatings were obtained on metallic and ceramic substrates. 13,14 Some zirconia powders were also formed via vapor-phase preparation. [15][16][17] These studies involved hightemperature oxidation of ZrCl 4 for submicrometer powders or pyrolysis of expensive organic zirconium sources like isopropoxide and tetra-tert-butoxide.…”