Formation of MoSi2 Layer by Hydrogen Reduction and Si-pack Cementation

Abstract

In this study, a molybdenum disilicide (MoSi2) coating process was investigated by hydrogen reduction and Si-pack cementation. At first, the metallic Mo coating was carried out by hydrogen reduction of MoO3 powder at 750 degrees C for various holding times (1, 2, 3 h) in hydrogen atmosphere. A 4.3 mu m thick metallic molybdenum thin film was formed at 3 h. MoSi2 was obtained by Si-pack cementation on molybdenum thin film through hydrogen reduction processing. It was carried out using Si : Al(2)0(3) : NH4Cl = 5 : 92 : 3 (wt%) packs at 900 degrees C for various holding times (30, 60, 90 min) in Ar atmosphere. When the holding time was 90 min, a MoSi2 layer was coated successfully and a 15.4 mu m thickness was observed.