Blanked Surface Characteristics of Amorphous Alloys with Local Microstructure Modification by Ultrashort Pulsed Laser

Amorphous alloys with no crystal structure, particularly Fe-based ones, exhibit excellent soft magnetic properties and are expected to be applied to motor cores because of their high magnetic flux density. However, they are difficult to machine because of their mechanical properties, such as high strength and toughness, owing to their unique structure. These mechanical properties of amorphous alloys change due to thermal microstructural changes, that is, structural relaxation and crystallization; however, the excellent magnetic properties also degrade. Therefore, this study proposes a new blanking method that improves the machinability of amorphous alloys without degrading their magnetic properties by thermally changing the microstructure of the local area where blanking is performed. This study investigated the effectiveness of ultrashort pulsed lasers, which have little thermal effect, on the local heat treatment of amorphous alloys. Furthermore, blanking tests were performed on the locally heat-treated amorphous alloys, and the blanking resistance values and characteristics of the blanked surfaces were evaluated.