SYNTHESS OF ULTRAFNE COMPOSITE FROMELEMENTAL POWDERSOF Ni-A-Nb-BVA COMBUSTION SYNTHESIS

In this study NbB2 reinforced Ni-Al ultrafine composite was fabricated using thermal explosion mode of combustion synthesis from the elemental of Ni, Al, Nb, and amorphous Boron powders. Microstructural evaluation and characterization of the end product together with elemental map distributions were inspected using scanning electron microscopy (SEM) and wavelength dispersive spectroscopy (WDS) respectively. Phase determination and chemical composition of the phase in the reaction product were identified by XRD method. The products contained NiAl and NbB, compounds without any intermediate phases. The NbB2 particles were homogenously dispersed into the NiAl matrix. Particle size of Nbb, reinforcements were in the range of 523-365 mm for NiAl10wt % NbB2 which rose to 977+551 nm for NiAl-40wt % NbB, as a result of increasing the reaction temperature with increasing the amount of boride phase. The dimension and distribution ofreinforcement makes the intermetallic composite powders suitable as precursor for thermal spray applications.

Keywords:

thermal explosion , SHS , NiAl , composite , coating materials