Microstructure of nickel aluminides formed in situ in aluminium matrix composites

Nickel aluminides formed in situ in aluminium matrix composites due to the interaction between nickel powder and the matrix were examined. The composite materials were obtained from mixtures of nickel powder and aluminium powder by hot pressing in vacuum in the temperature range of 500-640degreesC. Depending on hot pressing parameters, the morphology of nickel aluminide particles was layered or homogenous, and their size for the same precursor powder was growing as the pressing temperature increased. XRD, SEM, TEM and EDS characterization methods were used for the microstructure investigation.