# Aluminum (heat sinks, cable, structures)

Part ID: 10.02 · Layer 10 (Materials & upstream inputs)

Refined aluminum metal and mill products — sheet, extrusion, casting — used for heat sinks, cable conductors, and structural and enclosure parts across the data center.

Aluminum is the lighter, cheaper alternative to copper wherever conductivity per dollar (rather than per unit of cross-section) matters, and the default metal for anything that needs to be light, formable or heat-dissipating. It shows up as heat sinks on air-cooled components, as aluminum-conductor cable for lower-criticality runs, and as the structural and enclosure material in server chassis, racks, containment, prefabricated modules and building envelope framing (Layers 4, 5, 9). Supply runs from bauxite mining through alumina refining to smelting — an energy-intensive step that concentrates production in regions with cheap power — and then to rolling, extrusion and casting into finished shapes.
AI hardware shifts some of this mix: as GPUs move to direct-to-chip liquid cooling, the air-cooled heat-sink use case shrinks on the highest-density components even as overall server and rack volumes grow, while aluminum's structural role in chassis, rails, containment and modular buildings keeps expanding with data-center footprint. For investors, this is standard industrial-metals economics — smelter capacity, energy cost as a share of production cost, and trade policy — with data centers a small, growing claim on a market whose swing factor is autos, packaging, aerospace and construction.

**AI delta:** AI racks still use aluminum for chassis, rails and structure, but the highest-power components shift heat removal to liquid cold plates, so aluminum's role moves from primary thermal path toward structural and secondary-cooling uses as density rises.

## Companies

| Company | Role | Confidence | Ownership | Ticker | Note |
|---|---|---|---|---|---|
| Alcoa | manufacturer | inferred | public | AA |  |
| Arconic | manufacturer | inferred | subsidiary |  |  |
| Century | manufacturer | inferred | public | CENX |  |
| Chalco | manufacturer | inferred | public | 601600.SS |  |
| Constellium | manufacturer | inferred | public | CSTM |  |
| Kaiser | manufacturer | inferred | public | KALU |  |
| Norsk Hydro | manufacturer | inferred | public | NHY.OL |  |
| Novelis | manufacturer | inferred | subsidiary |  |  |
| Rio Tinto | manufacturer | inferred | public | RIO |  |
| EGA | manufacturer | inferred | private |  |  |

Confidence tags: disclosed = company/filing statement; reported = trade press or partner list; inferred = taxonomy lead.