Application of electroforming process to bulk amorphous Ni-W alloy

Abstract

Homogeneous bulk amorphous Ni-W alloy with thickness of more than 2 mm is fabricated by an electroforming process. By suppressing the side reaction and by preserving the mass balance between consumed ions by electrodeposition and supplemented ions by the solution of Ni and W anodes in the electroforming system, the standard deviation of W-concentration throughout the specimen is kept to 1.3 at%. As the result of micro-Vickers hardness tests, the standard deviation of micro-hardness decreases about 90% in bulk materials in comparison with thin-film materials fabricated by conventional electroforming process. This result indicates that it is important to minimize the fluctuation of W-concentration in the specimen for obtaining the micrometer-scale high reliability of hardness. The compressive strength of bulk amorphous Ni-W alloy is about 2.7 GPa. High compressive strength of amorphous Ni-W alloy can be clearly shown. © 2011 The Japan Institute of Metals.