Recent Advances in Multi-Functional Coatings for Soft Magnetic Composites

Abstract

During the past 50 years, the aim to reduce the eddy current losses in magnetic cores to a minimum led to the formulation of new materials starting from electrically insulated iron powders, today called Soft Magnetic Composites (SMC). Nowadays, this promising branch of materials is still held back by the mandatory tradeoff between energetic, electrical, magnetic, and mechanical performances. In most cases, the research activity focuses on the deposition of an insulating/binding layer, being one of the critical points in optimizing the final composite. This insulation usually is achieved by either inorganic or organic layer constituents. The main difference is the temperature limit since most inorganic materials typically withstand higher treatment temperatures. As a result, the literature shows many materials and process approaches, each one designed to meet a specific application. The present work summarizes the recent advances in state of the art, analyzing the relationship among material compositions and magnetic and mechanical properties. Each coating shows its own processing sets, which vary from simple mechanical mixing to advanced chemical methods to metallurgical treatments. From state of the art, Aluminum coatings are characterized by higher current losses and low mechanical properties. In contrast, higher mechanical properties are obtained by adopting Silicon coatings. The phosphates coatings show the best-balanced overall properties. Each coating type was thoroughly investigated and then compared with the literature background highlighting. The present paper thus represents a critical overview of the topic that could serve as a starting point for the design and development of new and high-performing coating solutions for SMCs. However, global research activity continuously refines the recipes, introducing new layer materials. The following steps and advances will determine whetherthese materials breakthrough in the market.

RETRACTED: Impact of High-Frequency Traveling-Wave Magnetic Fields on Low-Conductivity Liquids: Investigation and Potential Applications in the Chemical Industry

“…Soft magnetic materials have gained significant attention due to their unique properties and potential applications in various fields. Their excellent magnetic characteristics, including high permeability and low coercivity, make them suitable for transformers, inductors, and magnetic storage devices [57][58][59][60]. The integration of soft magnetic materials into composites and their use in magnetic fluid hyperthermia have opened up new opportunities for research and development.…”

Optimizing FeSiCr-Based Soft Magnetic Composites Using the Deionized Water as the Phosphating Solvent

“…Magnetic core loss is one of the most critical parameters of SMCs for high-frequency applications, consisting of hysteresis loss [6], eddy current loss, and residual loss [7]. In the MHz frequency, the eddy current loss of SMCs is dominant, dramatically increasing with increasing frequency [8].…”

Experimental Investigation of Joining the Metal/Polymer/Metal Composite Sheets by Clinching Method

“…Advancements in sandwich composites have resulted in the creation of materials that blend the elevated flexural stiffness and resistance to buckling found in metals with the lightweight characteristics of polymers. Composite materials combine materials with different properties to create a unique material with better features than its component materials [1][2][3]. The composite materials industry has achieved remarkable developments and has become the backbone of many industries, especially in aviation [4,5].…”