Ni-W Amorphous/Nanocrystalline Duplex Composite Produced by Electrodeposition

Abstract

Detailed characterizations are performed to identify the nanostructures of electrodeposited Ni-W alloys with grain size of 5 and 8 nm. Three-dimensional atom probe (3DAP) analyses have clarified that, in both alloys, experimentally measured W-concentration distributions fit well to the bimodal binomial distribution compared to the single binomial distribution. This result indicates the coexistence of W-depleted and W-enriched phases in the alloys. Nano-beam diffraction (NBD) patterns and energy dispersive x-ray spectroscopy (EDS) analyses revealed that the W-enriched phase is amorphous and that the W-depleted phase is nanocrystalline. The W-concentration visualizations on the cross section of 3DAP analysis volume identify them as amorphous/nanocrystalline duplex composites.