Can the iron core of an electromagnet be replaced by a steel bar and an aluminum bar?
Steel bar, aluminum rod not. There are three kinds of magnetic materials composed of elemental chemical elements, namely iron cobalt nickel three kinds of metal, they can only have magnetism, this property is a natural one, with its atomic structure, metal is not other. Steel bar is the main component of iron, so it can be.
The reason is: (1) aluminum can not be magnetized, and it can not increase the magnetic field strength of electromagnets. (2) aluminum conducts electricity so well that it will rapidly glow in alternating current electromagnets.
The core of DC electromagnet can be used instead of steel bars, but note that this rod must be "iron bar", otherwise the remanence is too big, can't release power.The core of an alternating current electromagnet cannot be replaced by a steel bar because it is heated by a larger eddy.No electromagnet can be used to make an iron core with an aluminum bar.
