Halide activated pack cementation technique was successfully used to elaborate protective coatings, based on silicon- or aluminum-rich intermetallic compounds, for a Nb-Ti-Al alloy. Thermodynamic computations showed that growth mechanism of coating involves different chemical reactions. The substrate shows a poor behavior in thermal oxidation with the formation of non-protective oxides and high solubility of oxygen in its microstructure. The effectiveness of the deposited MAl₃ and MSi₂ coatings to protect the substrate was demonstrated. Reliability and high oxidation resistance of these diffusion coatings are promoted by their good adherence to the substrate, capability to accommodate thermo-mechanical stress and ability to form adherent and compact Al₂O₃ and SiO₂ oxide scales. These oxide scales grow during the oxidation process at 900 and 1000 °C according to very low kinetics as demonstrated by the curves of mass change versus time. The mass changes of the coated substrate with aluminide and silicide were <1.5 mg·cm⁻² after 650 h of exposure at 1000 °C.

Halide activated pack cementation technique was successfully used to elaborate protective coatings, based on silicon- or aluminum-rich intermetallic compounds, for a Nb-Ti-Al alloy. Thermodynamic computations showed that growth mechanism of coating involves different chemical reactions. The substrate shows a poor behavior in thermal oxidation with the formation of non-protective oxides and high solubility of oxygen in its microstructure. The effectiveness of the deposited MAl₃ and MSi₂ coatings to protect the substrate was demonstrated. Reliability and high oxidation resistance of these diffusion coatings are promoted by their good adherence to the substrate, capability to accommodate thermo-mechanical stress and ability to form adherent and compact Al₂O₃和SiO ₂氧化皮。这些氧化皮在900和1000°C的氧化过程中会根据非常低的动力学增长，如质量变化随时间的曲线所示。在1000℃下暴露650h后，具有铝化物和硅化物的涂覆基材的质量变化＜1.5mg·cm ^-2。