Filament-reinforced nanocrystalline Ni composites by pulse electroforming

• Filament-reinforced nanocrystalline composites were first synthesized by electroforming.
• The UTS of composites linearly increased with filament volume fraction.
• The maximum UTS of 1680 MPa was obtained at a filament volume fraction of 40%.

Boron filament-reinforced nanocrystalline Ni composites were first synthesized by using pulse current and strong electrolyte flushing. It was found that the ultimate tensile strength (UTS) of the boron filament-reinforced nanocrystalline Ni composites was much greater than the UTS of pure nanocrystalline Ni. When the grain size of Ni was reduced from 200 nm to 50 nm by increasing the peak current density, the UTS of the composites first increased and then decreased, and had the maximum value at a grain size of 90 nm while the UTS of pure nanocrystalline Ni had the maximum value at a grain size of 70 nm. When the volume fraction of boron filament was less than 40%, the UTS of the composites increased linearly with the boron filament volume fraction and had a maximum value of 1680 MPa at a filament volume fraction of 40%. With the further increase of the filament volume fraction, the UTS began to reduce because of the internal voids.