How does one make "homemade" permanent magnets?

I would like to try and manufacture some permanent magnets for a project in my welding class, and I wasn't sure if it would be possible for me to do so.  I suppose a good addition to this question is "What is the process for making permanent magnets?"

To answer your question re the process for making a permanent magnet: different hard magnetic materials require different processes, often very different.

AlNiCo is just a particular alloy that can have a high coercivity. You mix together aluminum, nickel, and cobalt in the right proportions, melt it, and then heat treat it just right so it crystallizes in the right way. Voila!

However, the strongest magnets are anisotropic sintered materials. Here are the basic steps, for example, for NdFeB magnets (the strongest known):

Mix neodymium, iron, and boron in the right proportions (and add small amounts of cobalt, dysprosium, and other elements as needed).

Melt the mixture and then solidify very rapidly so that the alloy acquires just the right sized crystal grains. Too small and you won't get good remanence; too large and you won't get good coercivity. This is usually done these days through strip casting. Pour a thin stream of the molten mixture onto a rapidly spinning and well chilled copper drum. Collect the thin strips of alloy as they peel off. Everything has to be done with just the right combination of melt temperature, drum temperature, stream thickness and speed, etc.

Make the flakes of alloy decompose by exposing them to hydrogen. (This is called hydrogen decrepitation.) The flakes will turn into powder.

Further reduce the powder's particle size in a jet mill. This is a device that creates a fierce tornado into which the powder is poured. The particles grind themselves up into a very fine dust, which is milked off the perimeter of the jet. From here on out you want to keep the powder in sealed containers under a nitrogen atmosphere. It's very reactive. It will quickly oxidize if exposed to air and can even explode (like flour or sawdust).

Still under N2, press the powder into a block. Do this in a very strong magnetic field that will rotate the grains so that they all align along their "easy" axis, the crystal direction in which the alloy can be easily magnetized.

Put the blocks of alloy into a furnace and heat to a bit below the melting point (above 1000°C) in a vacuum. The block will sinter down to nearly 100% of full density.

Cut the blocks into the size and shape of the magnets you want with a diamond saw (NdFeB is a very hard material). Plate or coat ASAP. It's mostly Fe, which rusts, and most of the rest is Nd, which oxidizes even faster than Fe.

I'm not sure how samarium-cobalt magnets are made but they are also sintered, so the process may be similar.

I think the most reliable way would be to use an "electromagnet" to magnetize your iron. If you wrap an insulated wire around the piece of iron several times you can flow a current in the wire to create a magnetic field. If your piece of iron is in the shape of a rod, the magnetic field you produce with the wrapped wire will be in the axial direction.

The more times you wrap the wire around the rod (referred to as turns), the less current you need to flow to produce a suitable magnetic field. If you use the same number of turns and the same amount of current each time you make a magnet, all of your magnets should have the same strength (or magnetization).

Be careful when you setup a circuit to flow the current in the wire. Remember that the wire will most likely have a low resistance. If a stiff voltage is applied across the resistance, this could result in a very large current flow that may wreck the driving circuit or melt the insulation on the wire.

Basic physics and chemistry 101:
Taking an iron or ferrous steel bar, bang on it repeatedly with a hammer, or
Taking an iron or ferrous bar (or easier with a needle), use another magnet and stroke it in one direction only.
Eventually the non magnetic object will magnetize.  Striking the iron or subjecting it to a magnetic field causes the polarities of the iron atoms to align and intensify the field.

On a larger scale, you could subject heated or molten iron to a strong magnetic field while cooling slowly, this would also cause the atoms to align as they decrease in kinetic energy.

To demagnetize, heat the magnet, causing the alignment of the atoms to become chaotic.

Manufacturers make permanent magnets by exposing certain special  materials to a strong magnetic field. The field pulls on the molecules,  causing their charges to align and produce a magnetic field of their  own. Electromagnets