The effect of electropulsing treatment (EPT) on the solution behavior of aged Mg alloy AZ61 strip was investigated using scanning electron microscope (SEM) and x-ray diffraction (XRD). It was found that EPT accelerated tremendously the dissolution of ␤ phase into ␣ matrix in an aged Mg alloy AZ61 strip. The dissolution of ␤ phase took place in less than 4 s at relatively low temperature under EPT, compared with that in conventional heat treatment. A mechanism for rapid solid solution process during EPT was proposed based on the coupling of the thermal and athermal effects. The results in this investigation indicated that EPT played an important role in the nonequilibrium microstructural evolution in the alloy. It is supposed that EPT can provide a highly efficient approach for solid solution treatment of the alloy.

Melt spinning method has been widely applied for fabrication of Fe-based amorphous/nanocrystalline ribbons in industry. Compared with Fe-based amorphous/nanocrystalline alloys, Fe-6.5wt%Si high silicon steel is of low cost and has comparable excellent soft magnetic properties. Due to higher melting point and absence of supercooled liquid region, fabrication of Fe-6.5wt%Si ribbons is very hard and is only on lab scale. In this paper, we report that large scale fabrication of Fe-6.5wt%Si ribbons was successful and microstructures, ordered structures, and mechanical and soft magnetic properties of the ribbons were investigated. Due to rapid solidification rate, the ribbons were of ultrafine grains, and low degree of order and exhibited some extent of bending and tensile ductility. After heat treatment, excellent soft magnetic properties were obtained. Due to near-zero magnetostriction, the ribbons are promising to be used in electric devices with high frequencies where low noises are required.

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