Consolidation of co-base amorphous alloy powder by high-voltage discharging method

Amorphous Co₆₆Fe₄Ni₁Si₁₄B₁₅ alloy powders were consolidated by high-voltage discharging at various initial packing factors, specimen resistances and input energies. Compressed amorphous alloy powders with initial packing factor of 75% are consolidated retaining their amorphous structure below in input energy of 0.53 kJ/g. The relative density of the amorphous alloy compacts has a maximum value of approximately 95% when prepared with an initial packing factor of 85% and the input energy of 0.53 kJ/g. The densification increases on starting with a lower initial packing factor. The maximum increase in densification with the retaining amorphous structure is about 12%. The amorphous alloy compacts have no distinct pores and defects. The Vickers hardness of the compacts is nearly equal to that of melt-spun ribbons with the same composition. The coercive force does not change with their relative densities. However, magnetization increases with increasing relative density and it is saturated at 0.55 T above a relative density of 90%. The change of maximum permeability with their relative densities can be fitted to an equation with a parameter β which depends on the properties of the powders and the conditions for consolidation. The value of β has been found to be 0.007 in the present case.