Cold Sintered Metal–Ceramic Nanocomposites for High‐Frequency Inductors

Abstract

Power electronics, including those inspired by 5G and 6G revolutions, have escalated the demand for miniaturized energy‐efficient inductor components with higher power density, higher operating frequencies, and smaller device sizes. Recently, cold sintering has proved to be a powerful tool for fabricating ceramics. Here, novel metal–ceramic nanocomposites are prepared by cold sintering for the first time. As a model system, Fe‐based nanocrytalline alloys with NiZn ferrites and α‐Fe2O3 ceramics are cold sintered at 150 °C under a uniaxial pressure of 320 MPa. These nanocomposites illustrate dense microstructures, fine grains, and high electrical resistivities, allowing remarkable high‐frequency performance, such as permeability values of ≈11.5 at frequencies up to ≈1 GHz with corresponding quality factors reaching over 100 at tens of megahertz. The power inductors using the developed composite materials demonstrate low DC resistance (18.35 mΩ), high efficiency (≈98.2%), and high current rating with small form factors far superior to those available as commercial products. The results presented here indicate a dramatic advance in the materials science and development of inductor composite materials for power electronics applications. This synthesis route of metal–ceramic composites shows great potential in fabrication of new composite materials that are targeted for functional components.

Upcycling plastic waste into fully recyclable composites through cold sintering

“…24,25 Previous work has demonstrated unique composites made from salt and ceramic materials, 26 layered structures, 27 and metals. 28 As such, cold sintering provides the potential to integrate plastic waste with various other materials and likely opportunities for enhancing the sustainability of composite materials. The ability to sinter inorganic phases at modest temperatures opens the door for reprocessability, in a manner not typically possible for plastic composites.…”

Dual‐Band Filtering Dielectric Antenna Using High‐Quality‐Factor Y3Al5O12 Transparent Dielectric Ceramic

“…Functional ceramics have been applied in modern communication systems as dielectric resonators, filters, capacitors, and inductors, due to their high dielectric permittivity ( ε r ), high Q × f , and a small temperature coefficient of resonant frequency (TCF). [ 11–15 ] Dual‐functional DRA‐based transparent materials such as glasses, acrylic (PMMA), and transparent polymer have been designed to simultaneously serve as light‐focusing devices, decorative artwork, or the covering of light source. [ 16–18 ] Recently, it has also been verified that the MgAl 2 O 4 transparent dielectric ceramics can be applied in the fabrication of DRA.…”

Nacre‐Inspired, Efficient, and Multifunctional Soft Magnetic Composites by Cold Sintering Design

“…[29,30] Meanwhile, it has been demonstrated to be a powerful method to achieve high densification, fine grain size, and other microstructure designs in tens of materials. [28][29][30][31][32][33][34][35] Nevertheless, as far as we know, no literature has been reported on cold sintering design of nacre-like materials or using NH 4 HCO 3 aqueous solution as cold sintering solvent. In this work, based on a low sintering temperature of 180 C and a low uniaxial pressure of 320 MPa, the effect of transport solvents (i.e., NH 4 HCO 3 aqueous solution and deionized water) on the phase components, microstructure, magnetic properties, and mechanical strength of the cold-sintered SMCs has been systematically investigated.…”