Clean Technology 2011
H.W. Han, D.K. Ahn, H-J Ahn, W-W Park, K.Y. Sohn
Inje University, KR
melt-spinning, Si-Mn-Cr alloy, microstructure, electrochemical property
In this work, the microstructure and electrochemical properties of Si-Mn-Cr alloy specimens prepared by a rapid solidification process and a conventionally-solidified process have been investigated. Si70Mn15Cr15 alloy ribbons by atomic ratio were prepared by two different processes; arc-melting and arc-melting followed by melt spinning process. Microstructural evaluation and phase analysis were conducted by X-ray diffractometry (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) combined with energy-dispersive spectrometry (EDS). Results showed that the microstructures of melt-spun Si70Mn15Cr15 ribbons mainly consisted of Cr4MnSi10 phase combined with a fine eutectic that is composed of silicon and Mn4Si7 phases. Cr4MnSi10 phase presented a spherical shape of ~500nm in diameter while silicon showed lamellar shape of 30~50nm thick. The arc-melted Si70Mn15Cr15 ingot specimen showed relatively coarse microstructures, where Cr4MnSi10 phase was shown to be as a continuous matrix. Silicon with thicknesses of 1~5 m formed partially a eutectic with Mn4Si7 phase. The cycle performance of melt-spun Si70Mn15Cr15 ribbons was slightly improved compared to that of arc-melted Si70Mn15Cr15 ingot due to the fine microstructural scale. In this composition, the relative volume fraction of silicon was much smaller than that of Si-30Mn alloy. Cr4MnSi10 phase appears to involve in the intercalation reaction of lithium.