Fabricating Bulk Nanocrystalline Ni-W-B Alloys by Electrodeposition

作者：Matsui Isao^*; Li Mingjun; Omura Naoki

来源：Materials Transactions, 2017, 58(7): 1038-1041.

DOI：10.2320/matertrans.M2017047

• nanocrystalline alloys
• electrodeposition
• nickel-tungsten-boron alloys
• tensile testing
• trimethylamine-borane

In this study, we fabricated bulk nanocrystalline Ni-W-B alloys by electrodeposition, using trimethylamine-borane (TMAB) as a boron source, showing how B doping affects tensile properties. In electrodeposition, the TMAB concentration was varied from 0 to 5.0 g/L. Adding TMAB to the deposition bath increased the B content of the electrodeposited alloys up to 0.36 at%, but did not significantly change the W content or grain size. Adding more TMAB than 0.1 g/L drastically decreased the material's tensile elongation. Cross-sectional hardness tests on alloys with poor ductility revealed non-uniform hardness and that the initial layer had a high hardness of 6.3-8.7 GPa. This result indicated that the TMAB had immediately decomposed and that the boron decomposition product was mixed into the initial electrodeposited layer. In contrast, the alloys electrodeposited with 0.01-0.05 g/L TMAB showed good tensile elongation of 11%. Our results reveal the appropriate amount of added TMAB in order to produce electrodeposited bulk samples with good ductility.

• 出版日期2017