Fabrication of bulk nanocrystalline Al electrodeposited from a dimethylsulfone bath

► Dimethylsulfone (DMSO2) system for bulk nanocrystalline Al was developed, and it produced the bulk sample with thickness of 250 μm. ► The electrodeposited bulk nanocrystalline Al with grain size of approximately 40 nm exhibited high hardness of 1.7 GPa. ► The high hardness is caused by the reduction in the grain size to approximately 40 nm and solid solution strengthening from the Fe contaminant in the aluminum source.