ironcore

Ironcore is a term used to describe a central component composed mainly of iron or iron alloys that is placed inside electromagnetic devices to influence magnetic flux. In transformers, inductors, and electromagnets, an iron core increases magnetic permeability, reduces magnetic reluctance, and raises inductance and coupling efficiency. The performance depends on material properties; soft iron and silicon steel are common core materials for low- to medium-frequency applications, while ferrites are preferred for high-frequency devices.

Core design often involves laminations or ferrite structures to limit eddy currents and heat generation. Laminated steel sheets or grain-oriented electrical steel reduce eddy-current losses in power transformers, whereas ferrite cores are used in switch-mode power supplies and high-frequency inductors due to higher resistivity. Saturation, hysteresis, and temperature sensitivity are critical considerations; designers select materials and cross-sectional areas to maintain linear behavior in the intended operating range.

Earth science also uses the term "iron core" to refer to the planet's inner metallic region. The Earth's core consists of a solid inner core predominantly iron-nickel with a radius of about 1,220 kilometers, surrounded by a liquid outer core of similar composition. Convection in the liquid iron drives the geodynamo that generates Earth's magnetic field, while the solid inner core grows as the planet cools.