Fabrication of bulk nanocrystalline Al electrodeposited from a dimethylsulfone bath

Bulk nanocrystalline (nc) Al was electrodeposited from a mixture of dimethylsulfone-based electrolytes (DMSO2 bath). The DMSO2 bath demonstrates characteristics suitable for the fabrication of bulk nc Al, such as high current efficiency, good thermal stability, and low toxicity. The bulk nc Al having a thickness of 250 μm was electrodeposited from a dimethylsulfone bath. It displayed high hardness of about 1.7 GPa. The hardening source was analyzed on the basis of the Hall–Petch relationship and solid solution strengthening models. These analyses indicate that grain size reduction to approximately 40 nm and solid solution hardening by trace impurities contribute to the high hardness of the bulk nc Al.