Research on Deterioration Mechanism and High-Precision Modelling of the Core Loss for Amorphous Alloys after Wire-Cut Electric Discharge Machining

Abstract

Amorphous alloys (AAs) have the advantage of low core loss. Thus, they can be used in high-speed motor applications. However, compared with the nominal performances, the performance of the wire-cut electric discharge machine (W-EDM)-processed AA iron core changes significantly, which limits its popularization. This paper focuses on the performance degradation mechanism of the AA ribbon caused by W-EDM and establishes a modified core loss model after machining. First, a 308 × 15 mm ribbon-shaped AA sample machined by W-EDM was prepared. The characterization and analysis of the magnetic properties, phase, magnetic domain, nano-indentation, micro-morphology, and composition were carried out. In this paper, by analysing the variation in the magnetic domain distribution based on domain width and nano-mechanical properties, it is proposed that the performance degradation range of AA ribbons processed by W-EDM is within 1 mm from the edge. By comparing the microscopic morphology and chemical composition changes in the affected and the unaffected area, this paper presents a mechanism for the property deterioration of W-EDM-processed AA ribbons based on electrochemical corrosion. Finally, a modified loss model for W-EDM-processed AAs is established based on the division of the affected area. This model can significantly improve the accuracy of core loss estimation in the medium- and high-frequency bands commonly used in high-speed motors.

Recent Research in Wire Cut Electrical Discharge Machining Process

“…Tilekar et al (2014) used the Taguchi approach to study process optimization parameters for mild steel and aluminium. Surface roughness and Kerf width were determined using the following process parameters: wire feed 75, 80, 85 (mm/s), input current 1, 2, 3 (A), pulse on time 25, 32, 39 (µs), pulse off time 6, 8, 10 (µs), and so on [3]. Using the single objective Taguchi approach and the multi-objective grey relation grade, Durairaj et al (2013) examined the impact of process factors on stainless steel (SS304).…”

“…Finally, based on the partition of the affected area, a modified loss model for W-EDM-processed AAs is constructed. [3]. L. Selvarajan and K. Venkataramanan demonstrated the topography on EDMed surfaces and precisely drilled holes in the Si3N4-TiN conductive ceramic composites.…”