Bottlenecks in material cycle of nickel Kenichi Nakajima, Ichiro Daigo, Kenichi Okada, Shimpei Koike, Keisuke Nansai, Kazuyo Matsubae, Osamu Takeda and Takahiro Miki Matériaux & Techniques, 104 6-7 (2016) 604 Published online: 21 April 2017 DOI: 10.1051/mattech/2017011