부산대학교 도서관

In this study, we tried to improve the oxidation resistance of Mo–3Si–1B (wt%) alloy at intermediate (800 °C) and high temperature(1300 °C) after applying Si/Al pack cementation coatings. In addition, we examined structural changes and phasechange in the intermediate and high temperature oxidizing atmospheres to observe oxidation behaviors. The diffusion packcoatings were carried out with an NH4Factivator and both Si and Al powder mixtures. Mo–Si–B alloys were subjected todiffusion coatings of Si/Al powders at various temperatures in various time conditions at a temperature of 1100 °C. Whenthe pack coatings were carried out for 48 h, Mo(Si, Al)2 and Mo3Al8layers together with a T2 (Mo5SiB2) layer were successfullysynthesized on the substrate. After oxidation tests, an Al2O3protective oxide layer was formed by the diffusionof Al in an ambient atmosphere. The Si/Al pack cementation coatings provided excellent oxidation resistance through theformation of an Al2O3oxide layer. The enhanced oxidation behaviors are discussed in terms of microstructural evolution athigh temperatures.