Journal of Materials Science, Vol.43, No.21, 6912-6919, 2008
Preparation of NiAl-TiC nanocomposite by mechanical alloying
NiAl-TiC nanocomposite was successfully synthesized via a ball-milled mixture of Ni, Al, Ti, and graphite powders. The structural and morphological evolutions of the powders were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Results show that NiAl-TiC composite was obtained after 6 h of milling. The mean grain sizes of 6 and 10 nm were attained for NiAl and TiC at the end of milling, respectively. An annealing of 3 h milled sample at 600 degrees C led to the formation of Ni (Al, Ti, C) solid solution. NiAl-TiC nanocomposite that was formed in the 12 h milled sample is stable during an annealing at 600 degrees C. The mean grain size of NiAl at the 12 h milled powder increased during annealing at 600 degrees C. Maximum micro hardness value of 870 kg/mm(2) (8.7 GPa) was acquired from the 12 h milled powder. SEM images and particle size measurement showed that very fine spheroid particles (1 mu m) were procured at the end of milling.