Effects of quenching speeds on microstructure and magnetic properties of novel SmCo6.9Hf0.1(CNTs)0.05 melt-spun ribbons

✍ Scribed by Ji-Bing Sun; Dan Han; Chun-Xiang Cui; Wei Yang; Liang Li; Fan Yang

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 934 KB
• Volume: 57
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2009.02.039

✦ Synopsis

By adding carbon nanotubes (CNTs) to SmCo 6.9 Hf 0.1 , novel SmCo 6.9 Hf 0.1 (CNTs) 0.05 as-cast alloy has been prepared, which consists of Sm(Co,Hf) 7 as the main phase, a small amount of SmCo 5 and a particle-like grain boundary phase Hf(CNTs). SmCo 6.9 Hf 0.1 (CNTs) 0.05 ribbons melt-spun at speeds of 10-50 m s À1 have a single TbCu 7 -type structure. Increasing the quenching speed can result in a decrease in ribbon thickness and grain boundary width. Meanwhile, the grain size tends to be smaller and the grain boundary phase tends to be more dispersed. A new Sm(Co,Hf) 7 (CNTs) x boundary phase may be formed in SmCo 6.9 Hf 0.1 (CNTs) 0.05 ribbons. Increasing the quenching speed can also enhance coercivity, remanence and remanence ratio. The ribbons melt-spun at a speed of 50 m s À1 display the best magnetic properties: H ci = 18.781 kOe, M s2T = 76.87 emu g À1 , M r = 66.79 emu g À1 and M r /M s2T = 0.87.