Nickel aluminum superalloys created by the self-propagating high-temperature synthesis of nanoparticle reactants

摘要

Advancements in nanotechnology for material processing via combustion synthesis have spurred the development of superalloys that provide improved protective properties. Nanoscale reactant particles offer unique thermal properties and increased homogeneity that improve the microstructural features and macroscopic properties of the synthesized product. In this study nanoscale molybdenum trioxide (MoO3) particles were added to micron scale nickel (Ni) and aluminum (Al). The goal was to incorporate a nanoscale additive within the reactant matrix that would produce a superalloy by generating excessively high heating rates and creating controlled quantities of Al2O3 (a strengthening agent) within the microstructure of the alloy. Ignition and flame propagation were examined using a CO2 laser and imaging diagnostics that include a copper-vapor laser coupled with a high-speed camera. Product microstructure was examined using micro-x-ray diffraction analysis and scanning electron microscopy. Abrasion testing was performed to evaluate the wear resistance properties of the superalloy. Results show that adding MoO3 increases the flame temperature, results in greater ignition sensitivity, produces a more homogeneous microstructure, and increases the overall wear resistance of the product.