Specialist low-volume and hypercar bills of materials increasingly mix two material families that still confuse generic automotive RFQs: high-strength aluminium powders for laser powder-bed fusion, and cosmetic-grade carbon prepregs for visible structures. Neither is exotic in motorsport or aerospace. Both become programme risk when buyers specify “aluminium AM” or “carbon look” without locking alloy, process and quality systems.
Scalmalloy and Al-Sc: what the library entry should say
Scalmalloy is a patented aluminium-magnesium-scandium (Al-Mg-Sc) alloy family developed by APWORKS (Airbus subsidiary) specifically for metal additive manufacturing. APWORKS positions it as a high-strength AM aluminium able to challenge 7000-series properties in printed geometries, with a track record in aerospace, robotics, marine and motorsport, and approval under FIA regulations for relevant applications. Independent technical literature and producer materials emphasise high specific strength, useful ductility after appropriate heat treatment, corrosion resistance relative to many high-strength aluminiums, and a microstructure suited to laser powder-bed processes.
For LVHV buyers, the practical implications are supply and qualification, not brochure tensile numbers. Scandium-bearing powders are capacity-constrained and often licence-controlled; heat-treat and HIP routes change allowables; and “print the bracket in aluminium” is not interchangeable with a Scalmalloy-qualified structural node. Parallel proprietary systems — such as Czinger/Divergent’s Z301 aluminium used on 21C Spyder structural nodes — underline the same lesson: name the alloy, the powder lot pedigree, the machine park and the post-process recipe, or you do not have a controlled material.
Cosmetic CFRP prepreg: visual yield is a cost driver
On the composites side, structural prepreg and cosmetic prepreg are not the same SKU. Products such as SHD’s MTC575 (launched 2026 as a cosmetic-grade carbon prepreg for hypercar exteriors and luxury interiors) exist because exposed weave clarity, depth and batch consistency are customer-facing quality attributes. SHD’s own guidance to pair cosmetic surface plies with specified structural backing systems (e.g. MTC275) shows how visual BOMs are multi-material process stacks. Scrap on a visible aero panel or interior surround is rarely reworkable to show standard; it is remake.
A short RFQ checklist for materials leads
- AM aluminium: alloy designation (Scalmalloy grade / Z301 / AlSi10Mg), powder source, machine OEM, heat-treat/HIP, NDT standard, fatigue dataset.
- Scandium and specialty powder: dual-source feasibility, licence status, lead time, and geopolitical/supply concentration risk.
- Cosmetic prepreg: surface + backing ply callout, clear-coat compatibility, UV/yellowing criteria, weave orientation control, scrap/yield targets.
- Structural CFRP: fibre/resin system, autoclave vs OoA, FVF windows, and whether visual and structural plies share the same supplier.
- Aftersales: can a printed node or cosmetic panel be remade in five years with the same powder or prepreg lot family?
Procurement takeaway
Scalmalloy-class Al-Sc AM alloys and cosmetic CFRP prepregs are now core LVHV materials-library entries, not niche R&D options. Ground your scorecards in named, qualified systems used in motorsport and specialist automotive — and refuse vague “aluminium print” or “carbon finish” language that hides single-source and yield risk.
Sources: APWORKS Scalmalloy materials; Equispheres/APWORKS supply-chain announcements; SHD MTC575 public materials; Czinger/Divergent Z301 coverage as parallel AM aluminium practice. Autotrayce Editorial analysis.
