Abstract:Combustion Front Quenching (CFQ) experiment is brought to success in cylindrical steel mould by adding some Al-Ti-C powder that is accepted high exothermic system on the top of Mg-Ni samples. The physical and chemical changes of all region in the quenched samples during the combustion synthesis are followed by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS ) and x-ray diffraction (XRD). The results show that the synthesis of Mg_2Ni was directly rather than through other intermediates and solid-solid reaction existed at lower temperatures. The process of synthesis Mg_2Ni can be expressed as: (1) solid combustion in the preheat phase; (2) liquid combustion in the combustion process; (3) cooling and crystal of the product after the reaction; (4) uniformity of the composition in the heat preservation process.