Fe-78 wt% Ni ribbons were prepared by the melt spinning technique and the interactive contribution of the grain size and grain orientation on the magnetic properties was examined. Heat treatment at 673 K for 1 h followed by furnace cooling was performed to show the annealing impact. At three wheel speeds of 10, 20, and 30 m/s, the saturation magnetization nearly does not change. High wheel speed and heat treatment are inclined to promote the growth of <001> grains. Although the <001> orientation is not the easy axis of magnetization, the improvement of the texture in this direction makes the coercivity decrease, which counteracts the inverse effect of the grain size at high wheel speed. It indicates that for preparing soft magnetic ribbons, the interactive contribution of grain orientation variation and the grain size should be considered.
Nan WangRuining YangWenjing YaoJinfeng XuXixing Wen
The liquid-solid transitions of (Co2Si+CoSi) and (CoSi+CoSi2) eutectic alloys were realized in drop tube and the rapid eutectic growth mechanism of intermetallic compounds was examined. The experimental and calculated results indicate that with increasing Co content, the intermetallic compound prefers nucleating primarily. The eutectic microstructures experience the transitions of 'lamellar-anomalous-divorced' eutectic with undercooling. In undercooled state, the growth of CoSi intermetallic compound always lags behind others, and no matter how large the undercooling is, this intermetallic compound grows under the solutal diflusion control. The calculated coupled zone demonstrates that (Co2Si+CoSi) eutectic can form within certain undercooling regime, when the composition is in the range from 23.6% to 25.4% Si. And the calculated coupled zone of (CoSi+CoSi2) covers a composition range from 40.8% to 43.8% Si.
