Co₃CuSiSnY₁₂

Architectural potential

A heavily yttrium-loaded sintered metal with copper, cobalt and tin as minor modifiers, fired at 1100 °C and reaching 350 MPa. At building scale its natural place is sintered hardware in the bracket-to-connector register: façade clips for rainscreen cladding, CLT-to-steel shear plates, furniture joints for gallery benches, and custom nodes for small-span trusses in pavilion and exhibition architecture. Against structural steel the embodied CO₂ is down fifty-three per cent and the energy down seventy-four per cent, so the environmental argument carries moderately-repeated runs of identical nodes — the kind of specification that suits a prefabricated timber canopy or a steel-framed addition to an existing masonry building. No shape-memory flag accompanies this entry, so the piece sits as a static connector rather than an active one; its argument is fabricated geometry at medium cost, not mechanical responsiveness. Tin and copper push machining and finishing behaviour closer to a bronze than to a plain ferrous sinter, which makes the alloy friendly to threaded inserts and drilled attachments. The caveat is the same anomaly that recurs in this batch: the recorded density of 0.53 g/cm³ is implausible for a metal of this composition and reads as a porous or foamed sinter, which needs bench verification before any piece goes into structural service.

Material character

The face reads a quiet green-red copper — yttrium's silvery matrix cooled by cobalt, warmed by copper and tin, more muted than a bronze casting and paler than a clean steel sinter. At 0.53 g/cm³ over a 120×120×131 mm slab the piece firms single-handed on the bench, a distinctly lighter register than any solid metal expectation — softwood in the hand. Skin carries the sintered matte grain of a pressed-and-fired powder part, with visible micro-porosity under raking light. Edges cold-cut, kerf slightly ragged where the porous body grazes the blade. Reads dead on tap, a muffled acoustic unique to porous sinters.