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

Abstract

Advancements in nanotechnology for material processing via combustion synthesis have spurred the development of superalloys that provide improved protective properties. Nanoscalereactant 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 thereactant 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 wearresistance of the product.