Why can’t we add dye to metal to make coloured metal that is less susceptible to scratches?


It seems that we can add dye to plastics and get coloured plastics. Why can’t we just do the same with molten metal and get coloured metal? Rather, It seems like all the metal I have ever owned is just painted on the exterior of the item, and is vulnerable to flaking and being scratched off.

In: 2

If I recall correctly it’s because plastic is porous, i.e. able to absorb liquid, but metal is non porous and can’t absorb anything. Think of it like a sponge ball versus a glass ball. The sponge will absorb plenty of liquid and can hold the color of the dye. But the glass ball, even if melted down, can’t actually absorb any liquid and it ends up with things like air bubbles and other annoyances.

Paint on metal is usually for corrosion resistance. There are other ways to achieve this, but an isolating top layer of paint is easy, cheap, and effective, for many purposes.

Mixing a dye into molten metal is really hard as the temperature for iron to actually smelt and be liquid are incredibly high, and i don’t think that:

1: the dye would survive that temperature.

2: the dye would protect the metal from corrosion.

3: the dye probably won’t do anything, but worst case scenario, it could weaken the metal, rendering it unusable for the intended purpose.

So there are no real benefits to mix dye in and there may be adverse effects.

Because anything you incorporate into a metal has a huge effect on it’s properties. Particularly non-metals can potentially destabilize the structure of the metal that forms after forging and/or tempering, causing it to become weak or brittle.

I’m sure there are ways to do it naturally, but it would be more trouble than it’s worth. Plus paint comes with anti-rust/oxidation properties that you won’t necessarily get with additions.

Plastic can be colored because it’s typically transparent and translucent in its pure state, but metal is opaque and even incredibly thin plates can block 100% of the light, so you’d hardly be able to see any of the dye

Even then the dye would probably not stay together well because molten metal is really dense and stuff tends to float, and even if you manage that, the dye particles probably would reduce the metal proprieties somewhat

We do dye metals. Rose gold is gold dyed red by using copper. Similarly we do the same for white gold or bronze and brass.

A dye used on metals must be able to survive the melting point of metal and typically the only thing that can, is other metals. However, we don’t call these colored metals, we call them alloys. Alloying metals does a lot more than change their color so it’s not used in this way very often.