Formation of MoSi2–SiO2 coatings on molybdenum substrates by CVD/MOCVD

Coatings of MoSi2–SiO2 with uniform thickness and excellent adhesion were successfully deposited onto molybdenum substrate via chemical vapor deposition (CVD) of SiCl4/H2 and the subsequent metal-organic chemical vapor deposition (MOCVD) of TEOS/N2 at relatively low temperatures. Preliminary isothermal and cyclic oxidation tests indicated that SiO2 coated samples did not further degrade the oxidation resistance of MoSi2. The composition and phases of the metal-disilicide and silica coatings were studied by X-ray diffraction and Auger electron spectroscopy. The surface microstructures were investigated with field emission scanning electron microscopy.