Cu₄P₈Zr₁₈

Architectural potential

A zirconium-copper phosphide sintered at 1100 °C, dense and mechanically serious — the same hardware register as other sintered metals but in a small, heavy slab that points toward high-stress fittings rather than broad brackets. Three hundred and fifty megapascals of compression paired with a fifty-three-per-cent cut in embodied CO₂ against structural steel gives it a direct argument against cast-steel in seismic brackets, bearing pads under column bases, pile-cap dowels in timber hybrid structures, and heavy hinge pivots or threshold plates where the detail carries cyclic load. At 6.54 g/cm³ the billet sits firmly in the hand; the 70×70×31 mm slab at 200 g is a single connector-sized piece rather than a plate. Cost is the real competitive argument in this batch at €2.19 per unit — cheaper than erbium variants by a factor of five — so specification can move from one-off signature piece toward small-run replicated hardware. Tooling the die is the capital cost; once made, a run of identical brackets is feasible within the 500 g workshop ceiling. The caveat is the narrow batch ceiling: scaling beyond several hundred grams per pour demands an industrial sinter furnace rather than a studio kiln, so workshop prototyping and external production have to be planned from the start.

Material character

The slab reads a dense green-red copper surface with the phosphorus content dulling the matte into a dark patina-like finish — closer in tone to aged bronze than to freshly pressed copper. At 6.54 g/cm³ and 70×70×31 mm, the piece sits firmly on the bench and resists the one-handed lift; the density-to-size ratio is distinctly heavier than either the erbium variant or a typical cast-bronze sibling of the same volume. Surface sintered matte with a fine regular grain from the press die; edges pressed rather than cold-cut, slightly burred where the die parted. Rings short and high when tapped — the hard, dense ring of a sintered phosphide.