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Material World
Application

Additive manufacturing

Building an object by adding material rather than removing it — and a set of trade-offs almost exactly inverse to moulding.

An object is built layer by layer from a digital model, so geometric complexity costs nothing extra and no tooling is required at all. Both halves of that are the point: internal channels, lattices and shapes no mould could release become possible, and the first part costs about what the thousandth does.

The inverse is equally sharp. It is slow per part, the surface is stepped, and layer-built parts are usually weaker in the build direction than across it — an anisotropy that catches people who assume a printed part behaves like a moulded one.

Uses

Prototyping, which is still the largest use. Production of low-volume and high-complexity parts where a mould cannot be justified: aerospace brackets and fuel nozzles, patient-specific medical implants and surgical guides, dental aligners, and jigs and fixtures in factories that make something else.

The polymers are PLA and PETG for desktop machines, ABS and nylon for tougher parts, and PEEK where the application justifies the temperature and the cost. Metal powder-bed processes reach titanium, aluminium and nickel superalloys, and are where the aerospace value sits.

Medium confidence Weak evidence

How we know: checked recently · only one source, so there is nothing to cross-check it against · stated directly by the source.

How this connects

Where a connection has been confirmed by an outside reference, that reference is named beside it.

uses

  • PLA — material · the default desktop filament: it prints easily, barely warps, and softens near 60 °C, which is the limit on what it can be used for
  • ABS — material · tougher and more temperature-tolerant than PLA, and markedly harder to print because it warps as it cools
  • PEEK — material · at the demanding end, needing a heated chamber — cooled too fast it stays amorphous and loses the temperature resistance it was chosen for
  • Titanium — element · powder-bed fusion of aerospace brackets and patient-specific implants, which is where the industrial value of printing metal actually sits
  • Ti-6Al-4V — alloy · powder-bed fusion of aerospace brackets and patient-specific implants, where printing beats machining nine tenths of a billet away

Sources

  • Material World
    Our own writing
  • Wikidata
    Wikimedia Foundation · Creative Commons CC0 1.0 Universal (public domain dedication)

Questions this page answers

Where it comes from, and what it becomes

Follow Additive manufacturing back to what it starts as, and forward into what it becomes. Each step is a documented one — a real route material takes, not a chain of inference.

Upstream — what it comes from

  • Additive manufacturing → uses (powder-bed fusion of aerospace brackets and patient-specific implants, which is where the industrial value of printing metal actually sits) → Titanium → is produced by (as sponge, which must then be crushed, melted and cast before it is usable metal) → Kroll process → takes as input (the inert atmosphere, without which the titanium would take oxygen from the air) → Argon → is produced by (drawn from an intermediate height in the column, between nitrogen and oxygen) → Air separation → takes as input (the feedstock, and an unusual one in being free, unlimited and available anywhere — the cost is entirely the energy to liquefy it) → Air
  • Additive manufacturing → uses (tougher and more temperature-tolerant than PLA, and markedly harder to print because it warps as it cools) → ABS → is produced by (styrene and acrylonitrile polymerised in the presence of polybutadiene rubber, so the rubber phase is grafted in rather than blended) → Polymerisation → takes as input (as vinyl chloride, which is why more than half of PVC's weight is salt rather than oil) → Chlorine → is produced by (at the anode) → Chlor-alkali electrolysis → takes as input (as brine; the salt is the feedstock for both products at once) → Halite
  • Additive manufacturing → uses (at the demanding end, needing a heated chamber — cooled too fast it stays amorphous and loses the temperature resistance it was chosen for) → PEEK → is produced by (a step-growth polymerisation between aromatic monomers at high temperature in a polar solvent) → Polymerisation → takes as input (as vinyl chloride, which is why more than half of PVC's weight is salt rather than oil) → Chlorine → is produced by (at the anode) → Chlor-alkali electrolysis → takes as input (as brine; the salt is the feedstock for both products at once) → Halite
  • Additive manufacturing → uses (the default desktop filament: it prints easily, barely warps, and softens near 60 °C, which is the limit on what it can be used for) → PLA → is produced by (ring-opening polymerisation of lactide, itself made by fermenting plant sugar to lactic acid) → Polymerisation → takes as input (as vinyl chloride, which is why more than half of PVC's weight is salt rather than oil) → Chlorine → is produced by (at the anode) → Chlor-alkali electrolysis → takes as input (as brine; the salt is the feedstock for both products at once) → Halite
  • Additive manufacturing → uses (powder-bed fusion of aerospace brackets and patient-specific implants, where printing beats machining nine tenths of a billet away) → Ti-6Al-4V → is produced by (melted under vacuum or inert gas, because molten titanium reacts with essentially every crucible material and with air) → Alloying and melting → takes as input (the base metal of both brass and bronze) → Copper → is produced by (as blister copper, refined electrolytically afterwards) → Smelting → takes as input (roasted to drive off sulfur, then reduced to copper) → Chalcopyrite
  • Additive manufacturing → uses (powder-bed fusion of aerospace brackets and patient-specific implants, which is where the industrial value of printing metal actually sits) → Titanium → is produced by (as sponge, which must then be crushed, melted and cast before it is usable metal) → Kroll process → takes as input (converts the ore to a distillable tetrachloride, which is how the purification is done) → Chlorine → is produced by (at the anode) → Chlor-alkali electrolysis → takes as input (as brine; the salt is the feedstock for both products at once) → Halite

These are the most distinct paths back. Additive manufacturing can be traced through others besides.