Static Electropulsing-Induced Microstructural Changes and Their Effect on the Ultra-Precision Machining of Cold-Rolled AZ91 Alloy

The effects of electropulsing on the phase transformations of a cold-rolled Mg-9Al-1Zn alloy were studied using X-ray diffraction, back-scattered electron microscopy, transmission electron microscopy, and optical microscopy techniques. The results indicated that with increasing frequency of electropulsing, the decomposition and precipitation of β phase were tremendously accelerated sequentially. Electropulsing accelerated the decomposition of β phase by a factor of approximately 3600 times. The effects of the electropulsing-induced microstructural changes on machinability of the alloy, by single-point diamond turning, was discussed.