2007/12/12 by B. J. Senkowicz, B J Senkowicz, R. J. Mungall +11 · 3 citations
Engineering · Materials Science · Physics and Astronomy · #Aluminum Alloys Composites Properties #Boron and Carbon Nanomaterials Research #Superconductivity in MgB2 and Alloys #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1088/0953-2048/21/3/035009
12 pages, 11 figures
arxiv created 2007/12/12 · openalex publication_date 2008/02/08 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
Magnesium diboride (MgB 2 ) powder was mechanically alloyed by high-energy ball milling with C to a composition of Mg(B 0.95 C 0.05 ) 2 and then sintered at 1000 °C in a hot isostatic press. Milling times varied from 1 to 3000 min. Full C incorporation required only 30–60 min of milling. The grain size of sintered samples decreased with increased milling time to <30 nm for 20–50 h of milling. Milling had a weak detrimental effect on the connectivity. A strong irreversibility field ( H * ) increase (from 13.3 to 17.2 T at 4.2 K) due to increased milling time was observed and correlated linearly with inverse grain size (1/ d ). As a result, the high-field J c benefited greatly from lengthy powder milling. J c (8 T, 4.2 K) peaked at>80 000 A cm −2 with 1200 min of milling compared with only ∼26 000 A cm −2 for 60 min of milling. This non-compositional performance increase is attributed to grain refinement of the unsintered powder by milling, and to the probable suppression of grain growth by milling-induced MgO nanodispersions.