Exceptionally, it is not about the expensive ceramic disks here, but about lightweight construction in conventional brake disks. As you know, the can be made only from cast iron (above) or steel (bottom picture). Should someone tell something of aluminum, then is always only meant the pot. In picture 1 above, the is even of steel and saves therewith 15 percent weight according to manufacturer's specification
The required toothing by the two different materials is highly welcome because of the heat distribution and suitable for high torques or speeds. And of course the company Brembo proposes striking finishes as at the brake calipers. Soon to have in the Mercedes.
Now there is but a single, relatively inconspicuous disk completely of aluminum (picture) with coated brake surface, but is still in the stage of the prototype and intended for electric vehicles. Apparently one expects here significantly lower temperatures on the brake disks.
Of course, the electric motor in two or even four wheel hubs could bring the final breakthrough. The film draws attention to the large remaining space. Major disadvantage: The unsprung masses increase and thus good driving characteristics decrease. A step towards a solution to the problem could be the significantly lighter brake disk. 10/15