Development of the Ni-Based Metallic Glassy Alloys for PEFC Separator
We prepared the Ni80-xCrxP16B4 (x = 3, 6, 9, 12, 15, 18, 21, 24, 27 and 30 at.%) alloy ingots in an Ar flow atmosphere without evacuation and then produced the alloy ribbons by melt-spinning in evacuation and air. Their thermal stability and other charasteristics were studied and the alloy composition was optimized. A supercooled liquid state appeared at Cr content of more than 9 at.%, and their Tg and Tx increased with increasing Cr content. The 2 Tx increases up to about 45 K with increasing Cr content up to 15 at.%, and then saturates in more higher Cr content. Thus we select the Ni65Cr15P16B4 alloy as an optimized composition for PEFC separator. Moreover, the precise grooves were successfully formed under viscous flow process. The groove-formed sample possessed a single glassy phase, and the Tg, Tx and 2Tx were not changed.It indicates that the sample was not thermally affected by hot-pressing in this experimental condition.
Young Won Chang, Nack J. Kim and Chong Soo Lee
M. Yokoyama et al., "Development of the Ni-Based Metallic Glassy Alloys for PEFC Separator", Materials Science Forum, Vols. 561-565, pp. 1367-1370, 2007