# The Use of Polyimide as a Bonding Material to Improve the Mechanical Stability, Magnetic and Acoustic Properties of the Transformer Core Based on Amorphous Steel

## TL;DR

This paper introduces a polyimide binder that enhances the mechanical stability and performance of transformer cores made from amorphous steel.

## Contribution

A novel polyimide-based binder is developed to improve bonding and reduce losses in amorphous steel transformer cores.

## Key findings

- The polyimide binder significantly improved mechanical stability of amorphous metal ribbons.
- The binder reduced core losses and audible noise in the manufactured toroidal magnetic core prototype.
- Characterization techniques confirmed the anticorrosion and mechanical properties of the binder.

## Abstract

The constantly evolving electrification also entails an increase in requirements for the effective and efficient distribution of electricity with the lowest possible power losses. Such needs can be met by highly effective electrical devices, and one of them is a transformer whose main component is a magnetic core. Currently, one of the soft magnetic materials used alternatively for the production of transformer cores are amorphous metal strips with competitive losses. However, to successfully use these materials, a key problem must be solved: limited mechanical stability. The presented article describes the development and application of a polyimide-based binder for efficient bonding of an amorphous metal ribbon. The layered binder was characterized using confocal microscopy, scanning electron microscopy and Raman spectroscopy, and its anticorrosion and mechanical properties were examined. As a final step, a prototype of a toroidal magnetic core bonded with the binder was manufactured and subjected to the evaluation of no-load loss and the analysis of the emitted noise. It was confirmed that the proposed polyimide binder tremendously improved the mechanical stability while reducing core losses and audible noise.