Effect of Solidification Process on the Magnetic Properties of Samarium Cobalt Intermetallic Compounds

Abstract

Two SmCo₅ intermetallic compounds were made by using the raw material made through strip and book casting technique. The strip casting was performed on relatively low speed, whereas book casting was done in an indigenously made mold. The other processing parameters like ball milling time, sintering and heat treatment temperatures for both systems were kept constant. X-ray diffraction analysis revealed the presence of Sm₂Co₇ phase in book casted sintered samples whereas, no such peak was detected in case of strip casted sintered samples. Results of Differential thermal analysis, revealed the presence of Sm₅Co₁₉ phase in strip casting sintered samples, which has relatively higher intrinsic coercivity. Magnetic properties of strip cast sintered samples and book cast sintered samples demonstrated that the strip cast sintered samples had high coercivity i.e. 1940 kA/m as compared to the book cast sintered samples, further the strip cast sintered samples show more magnetic stability than book casted sintered samples. The samples tested at high temperature showed that strip casted sintered samples are more stable than book cast sintered samples.

Fig. 1 Fracture surface revealing the nano structured lamella within the AC-strip.