Liquid phase separation of Cu-Cr alloys during rapid cooling
(School of Science, Xi’an Jiaotong University, Xi’an 710049, China)
Abstract: The ribbons of Cu-Cr alloys with high Cr content (15%−35%, mass fraction) were prepared by rapid solidification. The microstructures of solidified samples were analyzed by scanning electron microscopy and transmission electron microscopy. The results reveal that a representative liquid phase separation microstructures are observed in Cu75Cr25 ribbons solidified at a cooling rate of about 104 K/s. The liquid phase separation is not restrained when the cooling rate is enhanced to about 107 K/s. However, the size of Cr particles solidified from Cr-rich liquid or Cr-rich regions in alloy melts could be refined by increasing the cooling rates. The size of Cr particles increases with increasing Cr contents when the ribbons contain 15% to 35%Cr.
Key words: Cu-Cr alloy; liquid phase separation; melt spinning; rapid cooling