Processing Routes — Cross-Cutting Comparison
This note compares the processing routes a materials engineer actually chooses between when turning a candidate composition into a usable part — casting vs forging vs rolling vs additive for metals, injection vs extrusion vs additive for polymers, pressing vs slip casting vs additive for ceramics, layup vs RTM vs filament winding for composites — across every MaterialsScience library note that touches a fabrication step. Each section gives the full route catalog by material class against the dimensions that drive selection (feature size, throughput, tooling cost, finish, waste). The closing decision tree maps part requirements onto the right route in one read; the semiconductor-process matrix lives in semiconductor-materials-and-process-deep and is referenced rather than duplicated.
See also
- crystallography-phase-diagrams
- mechanical-behavior-of-materials
- characterization-methods
- biomaterials
- biomaterials-advanced
- composite-materials-advanced
- soft-matter-and-self-assembly
- electronic-structure-and-computational-materials
- quantum-materials-and-topological-phases
- geopolymer-and-concrete-chemistry-deep
- semiconductor-materials-and-process-deep
- high-entropy-alloys-deep
- photocatalysts-deep
- alloy-and-superalloy-catalog
- polymer-properties-and-applications
- refractory-and-thin-film-deposition
- mof-cof-perovskite-catalog
1. The six axes every route choice answers
A working materials engineer scores any candidate route against six axes simultaneously. The textbook “process selection chart” (Ashby) reduces to these.
| Axis | Cheap end | Expensive end | Why it matters |
|---|---|---|---|
| Minimum feature size | sand cast (~3 mm) | EUV litho (~13 nm), focused-ion-beam (~5 nm) | sets which microstructural features survive |
| Geometric tolerance | sand cast (±1 mm) | precision EDM / grinding (±2 μm) | drives downstream finish + assembly cost |
| Throughput | die casting + extrusion (continuous, kt/yr) | LPBF additive (1 part / 100 hr) | dictates cost-per-part at volume |
| Capital cost | sand casting (kUSD) | 300 mm fab ($10B+) | who can afford to play |
| Tooling cost per geometry | additive ($0 — geometry-free) | die forging ($0.5–5M per die set) | break-even quantity vs additive |
| Material waste | net-shape forging (~0%) | machining-from-billet (~80% chips) | E-factor + cost when material is gold or Ti |
A useful rule: the route that wins at 1 part/yr almost never wins at 10⁶ parts/yr, and vice versa. Additive wins at low N and high complexity; net-shape forging or die casting wins at high N and modest complexity. Most parts cross the break-even at 100–10,000 units depending on geometry.
2. Metals — primary processing routes
The metallic-part toolbox. By 2026 every traditional route has a CNC + simulation overlay (DEFORM, Forge NxT, MAGMA, Flow-3D); additive is now mature enough to displace specific niches without displacing the bulk.
2.1 Casting — liquid-metal to net-shape
| Route | Min feature | Typical tolerance | Throughput | Capex | Where it wins | Where it loses | Linked note |
|---|---|---|---|---|---|---|---|
| Sand casting | 3 mm | ±0.5–2 mm | low–medium | low | one-offs, large parts (engine blocks, manhole covers, art) | finish requires machining; porosity | alloy-and-superalloy-catalog |
| Investment (lost-wax) casting | 0.5 mm | ±0.1 mm | medium | medium | superalloy turbine blades (single-crystal CMSX-4), jewelry, medical implants | wax pattern cost; lead time | alloy-and-superalloy-catalog |
| Die casting (high-pressure) | 0.5 mm | ±0.05 mm | very high (k parts/hr) | high ($0.5–3M/die) | Al, Zn, Mg structural parts at scale (automotive housings) | only for low-melting alloys; porosity | alloy-and-superalloy-catalog |
| Permanent (gravity) mold casting | 1 mm | ±0.2 mm | medium | medium | Al wheels, cookware | die life limits geometries | alloy-and-superalloy-catalog |
| Lost-foam casting | 2 mm | ±0.5 mm | medium | low–medium | complex internal passages (engine blocks, pump housings) | foam-pattern handling | alloy-and-superalloy-catalog |
| Squeeze casting | 1 mm | ±0.1 mm | medium | high | high-integrity Al pistons + MMC infiltration | longer cycle; tooling cost | alloy-and-superalloy-catalog |
| Thixoforming (semi-solid) | 1 mm | ±0.1 mm | medium | high | low-porosity Al/Mg structural | feedstock prep (globular microstructure) | alloy-and-superalloy-catalog |
| Spin casting | 0.5 mm | ±0.05 mm | high | low–medium | small symmetric parts (jewelry, low-melt prototypes) | rubber-mold lifetime | alloy-and-superalloy-catalog |
| Single-crystal (Bridgman-Stockbarger) | sub-grain | ±0.05 mm | very low | very high | turbine blades CMSX-4 / Rene N6 / TMS-238 | very slow withdrawal rate | alloy-and-superalloy-catalog |
| Directional solidification (DS) | grain-parallel | ±0.1 mm | low | high | columnar-grain turbine blades | controlled gradient required | alloy-and-superalloy-catalog |
2.2 Forging — solid-state deformation
| Route | Min feature | Typical tolerance | Throughput | Capex | Where it wins | Where it loses | Linked note |
|---|---|---|---|---|---|---|---|
| Open-die forging | 10 mm | ±2 mm | low | medium | very large parts (shafts, turbine discs, nuclear pressure vessels) | rough finish; lots of waste | alloy-and-superalloy-catalog |
| Closed-die / impression-die forging | 1 mm | ±0.2 mm | high | very high ($0.5–5M/die) | high-volume crankshafts, con-rods, fasteners | tooling cost; only for kN parts | mechanical-behavior-of-materials |
| Hot forging | 1 mm | ±0.2 mm | high | high | Ti, Ni-superalloys, steels above recrystallization | scale + oxidation | mechanical-behavior-of-materials |
| Cold forging | 0.5 mm | ±0.05 mm | very high | high | fasteners, small bearings | limited deformation; cracking | mechanical-behavior-of-materials |
| Ring rolling | radial-uniform | ±0.5 mm | low–medium | very high | bearing races, turbine cases, rocket tankage | very specific geometry | alloy-and-superalloy-catalog |
| Rotary forging | 0.5 mm | ±0.1 mm | medium | high | axisymmetric (axles, gears) | restricted symmetry | alloy-and-superalloy-catalog |
| Isothermal forging | 0.5 mm | ±0.05 mm | low | very high | superalloy turbine discs near net shape | very expensive dies (Mo-TZM) | alloy-and-superalloy-catalog |
2.3 Rolling — for sheet, plate, foil
| Route | Output | Min thickness | Throughput | Where it wins |
|---|---|---|---|---|
| Hot rolling | plate, strip, bar | 1.5 mm | very high (kt/hr) | bulk plate (shipbuilding, structural) |
| Cold rolling | sheet, foil | 0.1 mm (steel), 0.006 mm (Al foil) | high | tighter tolerance + better finish than hot |
| Cluster mill (Sendzimir) | thin stainless / Si-steel | 0.05 mm | medium | hard-to-roll alloys |
| Planetary rolling | dramatic reduction in one pass | 0.1 mm | medium | wide thin Al / Cu strip |
| Cross rolling | tube + ball blanks | — | medium | seamless tube + bearing-ball blanks |
2.4 Extrusion, drawing, machining
| Route | What it does | Where it wins | Linked note |
|---|---|---|---|
| Direct extrusion | force billet through die | Al window frames, copper bus bars | alloy-and-superalloy-catalog |
| Indirect extrusion | die moves into stationary billet | lower friction; harder alloys | alloy-and-superalloy-catalog |
| Hydrostatic extrusion | pressurized fluid pushes billet | brittle materials (W, Be) | alloy-and-superalloy-catalog |
| Impact extrusion | high-speed strike → cup | Al / brass cosmetic tubes | alloy-and-superalloy-catalog |
| Co-extrusion | core + sheath together | clad cables, bi-metallic strips | alloy-and-superalloy-catalog |
| Wire drawing | reduce by pulling through die | electrical wire, music-wire | mechanical-behavior-of-materials |
| Tube drawing | thin-wall tubing | medical, fuel injection | mechanical-behavior-of-materials |
| Cup / deep drawing | sheet → cup | beverage cans, cookware | mechanical-behavior-of-materials |
| Ironing | thin can wall | drawn-and-ironed beverage cans | mechanical-behavior-of-materials |
| Hydraulic deep drawing | hydroforming complex shells | automotive body panels, aerospace bulkheads | mechanical-behavior-of-materials |
| Turning (lathe) | rotating part, single-point tool | axisymmetric machining workhorse | alloy-and-superalloy-catalog |
| Milling (5-axis) | rotating tool, fixed part | complex pocketed parts (airframe ribs) | alloy-and-superalloy-catalog |
| Drilling | round holes | universal | — |
| Grinding | abrasive finish | hardened steels, ceramic finish | characterization-methods |
| EDM (electric discharge) | spark erosion | hardened tool steel, exotic alloys | alloy-and-superalloy-catalog |
| ECM (electrochemical) | anodic dissolution | exotic alloys (Inconel, Ti), no HAZ | alloy-and-superalloy-catalog |
| Waterjet | abrasive slurry | composites + sandwich panels | composite-materials-advanced |
| Laser cutting | fiber laser CO₂ | sheet metal, polymer, thin ceramic | composite-materials-advanced |
| Plasma cutting | ionized gas | thick steel plate | alloy-and-superalloy-catalog |
2.5 Metal additive
| Route | Acronym | Powder/wire | Resolution | Build rate | Where it wins | Linked note |
|---|---|---|---|---|---|---|
| Direct Metal Laser Sintering | DMLS | powder bed | 30 μm layers, 60 μm features | 5–20 cm³/hr | medical implants (Ti6Al4V), aerospace bracketry (EOS, SLM Solutions/Nikon, GE Additive) | alloy-and-superalloy-catalog |
| Selective Laser Melting | SLM | powder bed | 30 μm layers | 10–80 cm³/hr | structural Al + Ti + Inconel (SLM Solutions/Nikon NXG XII 600) | alloy-and-superalloy-catalog |
| Laser Powder Bed Fusion | LPBF | powder bed | 20–60 μm | 10–80 cm³/hr | the umbrella term for SLM/DMLS as of ISO/ASTM 52900 | alloy-and-superalloy-catalog |
| Electron Beam Melting | EBM | powder bed (vacuum) | 50–70 μm | 20–80 cm³/hr | reactive alloys (Ti, refractory) — Arcam (GE Additive), JEOL JAM-5200EBM | alloy-and-superalloy-catalog |
| Directed Energy Deposition | DED | wire or powder + laser/EB/plasma | 0.5–2 mm | 100–8,000 cm³/hr | repair + cladding + large parts (Trumpf, BeAM, DM3D, Sciaky EBAM) | alloy-and-superalloy-catalog |
| Laser Metal Deposition | LMD | powder + laser | 0.5–1 mm | 50–500 cm³/hr | functional gradient + repair | alloy-and-superalloy-catalog |
| Binder Jetting | BJT | powder + binder, then sinter | 50 μm | high (vat-level) | high-throughput steel/Cu/CCS (Desktop Metal, ExOne / Desktop Metal X-series, HP Metal Jet S100) | alloy-and-superalloy-catalog |
| Cold Spray | CS | powder, supersonic gas | 100 μm | 100–1,000 cm³/hr | structural repair, no melting (TWI Cambridge, Plasma Giken, Impact Innovations) | alloy-and-superalloy-catalog |
| WAAM (Wire-Arc Additive) | WAAM | wire + arc | 2–4 mm | 1,000–8,000 cm³/hr | very large structural (Cranfield/Lincoln Electric, RAMLAB shipyard) | alloy-and-superalloy-catalog |
3. Polymers
Polymer processing is dominated by injection molding and extrusion; everything else is a specialty. By 2026 thermoset RTM and 3D printing have grown but molding is still ~60% of polymer tonnage.
| Route | Throughput | Min feature | Tolerances | Capex | Where it wins | Where it loses | Linked note |
|---|---|---|---|---|---|---|---|
| Injection molding (single-shot) | very high | 0.1 mm | ±0.05 mm | high ($50k–2M tool) | break-even ~10k parts; lego bricks at 4 ppm tolerance | tooling cost; weld lines | polymer-properties-and-applications |
| 2K (two-shot) injection molding | high | 0.1 mm | ±0.05 mm | very high | overmolded handles, soft-touch grips | tool complexity | polymer-properties-and-applications |
| Insert molding | medium | 0.1 mm | ±0.05 mm | high | embedded threaded inserts, sensors-in-plastic | insert placement automation | polymer-properties-and-applications |
| Gas-assisted injection | high | — | ±0.05 mm | high | hollow + thick parts (handles, panels) | flow + venting design | polymer-properties-and-applications |
| Structural foam injection | medium | — | ±0.1 mm | medium | low-density large parts | surface finish (“swirl marks”) | polymer-properties-and-applications |
| Single-screw extrusion | very high | profile | ±0.2 mm | medium | pipe, profile, film | only constant cross-section | polymer-properties-and-applications |
| Twin-screw extrusion | very high | profile | ±0.2 mm | medium-high | compounding, masterbatch, reactive extrusion | shear-sensitive polymers | polymer-properties-and-applications |
| Blown-film extrusion | very high | μm-thick | ±2% | medium | LDPE/LLDPE shopping bags, agri film | thinness ⇄ rate trade | polymer-properties-and-applications |
| Sheet extrusion | very high | mm-thick sheet | ±0.1 mm | medium-high | thermoforming feedstock | thick gauges sag | polymer-properties-and-applications |
| Profile extrusion | very high | profile | ±0.2 mm | medium | window frames, seals | constant cross-section only | polymer-properties-and-applications |
| Co-extrusion | very high | layered | ±0.1 mm | high | multilayer barrier (food packaging) | layer adhesion | polymer-properties-and-applications |
| Extrusion blow molding | high | hollow | ±0.5 mm | medium | bottles, fuel tanks | wall-thickness control | polymer-properties-and-applications |
| Injection blow molding | high | small hollow | ±0.1 mm | high | pharma bottles, precision finish | smaller parts only | polymer-properties-and-applications |
| Stretch blow molding | very high | PET bottle | ±0.05 mm | high | PET drink bottles (biaxial orientation) | only orientable polymers | polymer-properties-and-applications |
| Vacuum thermoforming | medium | sheet-thick | ±0.5 mm | low-medium | low-volume packaging, signage | sharp corners thin | polymer-properties-and-applications |
| Pressure thermoforming | medium | sheet-thick | ±0.3 mm | medium | sharper features than vacuum | tooling | polymer-properties-and-applications |
| Plug-assist thermoforming | medium | deep | ±0.3 mm | medium | drink cups, deep packaging | wall-uniformity tradeoff | polymer-properties-and-applications |
| Drape thermoforming | low | gentle | ±0.5 mm | low | prototyping, large gentle curvature | feature definition | polymer-properties-and-applications |
| Rotational molding | low | large hollow | ±1 mm | low | kayaks, agricultural tanks, large hollow toys | slow cycle (10–60 min) | polymer-properties-and-applications |
| Compression molding (BMC / SMC) | medium | filled | ±0.2 mm | medium | sheet/bulk-molding compound (auto body panels, electrical housings) | thermoset only; cycle longer than thermoplast injection | composite-materials-advanced |
| Transfer molding | medium | small | ±0.05 mm | high | semiconductor encapsulation, electronic potting | thermoset cure | semiconductor-materials-and-process-deep |
| Casting (urethane, epoxy) | low | mm | ±0.1 mm | low | prototypes, low-volume parts | air entrainment, cure time | polymer-properties-and-applications |
| FDM / FFF additive | low | 100–500 μm | ±0.2 mm | very low | prototypes, low-volume, end-use jigs (Bambu, Prusa, Markforged, Ultimaker, Stratasys F-series) | layer adhesion in Z | polymer-properties-and-applications |
| SLA stereolithography | low | 25–100 μm | ±0.05 mm | low-medium | dental, jewelry models, master patterns (Formlabs Form 4, 3D Systems ProJet, Carbon M3) | photopolymer brittleness | polymer-properties-and-applications |
| DLP | low | 25–100 μm | ±0.05 mm | low-medium | dental, jewelry, mass-produced repeatable patterns | resin handling | polymer-properties-and-applications |
| SLS (polymer powder bed) | low | 60–150 μm | ±0.1 mm | medium-high | functional prototypes + low-volume nylon production (EOS P-series, Sintratec, HP MJF complementary) | porosity, dye limits | polymer-properties-and-applications |
| MJF (Multi Jet Fusion HP) | low-medium | 80 μm | ±0.1 mm | medium-high | volume production nylon (HP 5200 series) | color limited; HP feedstock | polymer-properties-and-applications |
| PolyJet (Stratasys) | low | 16 μm | ±0.05 mm | medium-high | multi-material, full-color, prototypes (J55, J850) | photopolymer brittleness | polymer-properties-and-applications |
| CLIP (Carbon) | low | 25 μm | ±0.05 mm | medium-high | end-use elastomer + tough resin, dental (Carbon M3, Carbon Production Network) | resin price | polymer-properties-and-applications |
| LSP (large-scale polymer additive) | medium-high | 1–3 mm | ±1 mm | high | very large parts, BAAM (ORNL/Cincinnati), Thermwood LSAM | finish; layer lines | polymer-properties-and-applications |
4. Ceramics
Ceramic processing is fundamentally a powder-handling discipline — green-body shape, then sinter. Brittleness during green-body handling and shrinkage on sintering (10–20%) drive the route choice.
| Route | Min feature | Tolerances (post-sinter) | Throughput | Where it wins | Where it loses | Linked note |
|---|---|---|---|---|---|---|
| Uniaxial dry pressing | 0.5 mm | ±0.5% | very high | tiles, electrical insulators, simple geometries | density gradients; weak compacts | crystallography-phase-diagrams |
| Cold isostatic pressing (CIP) | 0.5 mm | ±0.5% | medium | uniform-density green bodies (oxygen sensors, ceramic ball bearings) | tooling (rubber bags) | crystallography-phase-diagrams |
| Hot isostatic pressing (HIP) | 0.1 mm | ±0.2% | low | full-density ceramics, defect closure, also for metal AM post-processing | very high capex | refractory-and-thin-film-deposition |
| Slip casting | 1 mm | ±2% | medium | hollow ceramics (sanitary ware, complex pottery shapes) | plaster mold wear; slow | refractory-and-thin-film-deposition |
| Tape casting | 10 μm thick | ±2% | high | multilayer ceramic capacitors (MLCC), SOFC + battery separators | thin sheet only | refractory-and-thin-film-deposition |
| Ceramic extrusion | 1 mm | ±1% | very high | catalyst supports, honeycomb DPF / SCR / GPF, brick | constant cross-section | photocatalysts-deep |
| Ceramic injection molding (CIM) | 0.1 mm | ±0.3% | high | small precision ceramic parts (zirconia dental abutments) | binder removal step (debinding) | biomaterials |
| Metal injection molding (MIM) | 0.1 mm | ±0.3% | high | small precision metal parts (firearm + medical) | debinding + sintering similar to ceramics | alloy-and-superalloy-catalog |
| Binder jet additive (ceramic) | 50 μm | ±1% | medium | sand cores, refractory crucibles (ExOne S-Max, voxeljet VX, Desktop Metal Shop) | porosity (60–80% green density) | refractory-and-thin-film-deposition |
| DLP ceramic (vat photopolymer) | 25 μm | ±0.5% | low | dental restorations, lithography masks, micro-fluidic (Lithoz CeraFab, 3DCeram, Admatec) | small build envelope | biomaterials |
| SLA-ceramic (3DCeram, Tethon) | 25 μm | ±0.5% | low | high-resolution dental + jewelry | resin cost | biomaterials |
| LASE (Laser-Assisted Slurry Extrusion) | 50 μm | ±1% | medium | complex ceramic geometries | new (commercializing ~2024) | refractory-and-thin-film-deposition |
| Conventional sintering | bulk | inherits | very high | universal | long hold + slow ramp | crystallography-phase-diagrams |
| Spark plasma sintering (SPS) / FAST | bulk | ±0.5% | medium | full density, no grain growth (transparent ceramics, refractory) | small build size; expensive | refractory-and-thin-film-deposition |
| Flash sintering | bulk | ±0.5% | high | seconds-timescale, low temperature | electrode contact + cracking | refractory-and-thin-film-deposition |
| Microwave sintering | bulk | inherits | medium | dielectric ceramics with selective heating | nonuniform heating | refractory-and-thin-film-deposition |
| HIP post-processing | bulk | ±0.2% | low | defect closure in turbine castings, dense ceramic finishing | very high capex | alloy-and-superalloy-catalog |
| 2-step sintering | bulk | inherits | medium | nano-grained ceramics (Chen-Wang protocol) | tight T-profile | crystallography-phase-diagrams |
| RBSiC (reaction-bonded SiC) | bulk | ±1% | medium | armor, semicon process chambers (Saint-Gobain Hexoloy SE) | residual Si phase | refractory-and-thin-film-deposition |
| RBSN (reaction-bonded Si₃N₄) | bulk | ±1% | medium | aerospace bearings, mechanical seals | residual porosity | refractory-and-thin-film-deposition |
| CVD ceramic (β-SiC, BN) | thin film + bulk | ±1 μm | low | semicon coatings, CMC matrix infiltration | very slow | semiconductor-materials-and-process-deep |
| CVI (chemical vapor infiltration) | bulk preform | ±5% | very low | C/SiC and SiC/SiC ceramic matrix composites for aerospace (GE Catalyst, CFM LEAP, JT9D) | months to fill | composite-materials-advanced |
| Sol-gel | film + monolith | ±1% | medium | optical coatings, aerogels, photocatalysts (TiO₂) | shrinkage on drying | photocatalysts-deep |
5. Composites
Composite processing splits by fiber form (woven cloth, unidirectional tape, chopped, continuous) and matrix state (prepreg vs liquid resin vs molten).
| Route | Fiber input | Matrix | Throughput | Capex | Where it wins | Where it loses | Linked note |
|---|---|---|---|---|---|---|---|
| Hand layup | cloth / mat | wet resin or prepreg | very low | low | one-offs, racing, repair | quality dispersion human | composite-materials-advanced |
| Automated Tape Layup (ATL) | UD tape | prepreg | medium | very high ($5–20M head) | aerospace skins (787 fuselage, F-35) | only flat / mildly curved | composite-materials-advanced |
| Automated Fiber Placement (AFP) | narrow tow | prepreg | medium | very high | complex curvatures (Boeing 777X spar, A350 fuselage barrels — Coriolis, Electroimpact, MTorres) | head cost; programming complexity | composite-materials-advanced |
| Prepreg + autoclave | UD or fabric prepreg | epoxy / cyanate / BMI | low | very high | aerospace primary structure (gold standard) | autoclave cost + slow | composite-materials-advanced |
| OOA (out-of-autoclave) prepreg | UD or fabric prepreg | toughened resin | medium | medium | aerospace secondary, marine, automotive | porosity if vacuum-bag-only | composite-materials-advanced |
| RTM (Resin Transfer Molding) | preform fabric | liquid epoxy / VE / PA / PPS | medium | high | mid-volume parts (BMW i3 LifeDrive carbon, Aston Martin DBR9) | resin-flow design difficult | composite-materials-advanced |
| HP-RTM (high-pressure) | preform fabric | epoxy fast-cure | high | very high | automotive structural carbon (BMW 7-series, Audi A8 multi-material) | tool cost; warpage | composite-materials-advanced |
| VARTM (vacuum-assisted RTM) | preform fabric | LV epoxy / VE | medium | medium | wind blade roots, large boat hulls (Vestas, Siemens Gamesa, Nordex) | resin-rich corners | composite-materials-advanced |
| Vacuum infusion (SCRIMP) | preform | LV resin | medium | medium | very large parts (wind blades 100+ m, ship hulls) | flow-front modeling | composite-materials-advanced |
| Filament winding | tow + roving | wet or prepreg | high | medium | pressure vessels (H₂ tanks 700 bar, COPV), rocket motor cases (Hexcel, MR&D, Mikrosam) | only axisymmetric | composite-materials-advanced |
| Pultrusion | continuous roving | thermoset | very high | medium | constant cross-section (rebar, structural shapes, ladder rails) | constant section only | composite-materials-advanced |
| BMC (Bulk Molding Compound) | chopped + filler | thermoset paste | high | medium | electrical housings, automotive | low strength vs UD | composite-materials-advanced |
| SMC (Sheet Molding Compound) | chopped fiber sheet | unsaturated polyester | high | medium-high | auto body panels (truck beds, hoods) | finish quality | composite-materials-advanced |
| Thermoplastic stamping | thermoplastic prepreg | PEEK / PEKK / PPS | very high | high | aerospace thermoplastic clips + brackets (Toray Cetex, TenCate) | tooling | composite-materials-advanced |
| CFC additive (continuous fiber) | continuous filament | thermoplastic | low-medium | medium | end-use composite parts (Markforged X7 + FX20, Anisoprint, Arevo, Continuous Composites CF3D, 9T Labs Red Series, Orbital Composites) | layer-to-layer | composite-materials-advanced |
| CMC processing (CVI + PIP + melt-infiltration) | SiC fiber | SiC matrix | very low | very high | aero engine hot section (GE LEAP shrouds, GE9X turbine nozzles) | route is months long | composite-materials-advanced |
6. Semiconductors / electronics (pointer only)
The semiconductor process matrix (depositions + lithography + etch + CMP + dopant) is exhaustive and belongs in its own note. See:
- semiconductor-materials-and-process-deep — deposition (PVD/CVD/ALD/MOCVD), patterning (DUV/EUV/NIL/EBL), etch (RIE/ICP/ALE), CMP, ion-implant, RTP.
- refractory-and-thin-film-deposition — thin-film and refractory-coating routes.
- quantum-materials-and-topological-phases — MBE + cleanroom for quantum devices.
This comparison focuses on bulk-materials side processing, not microfabrication.
7. Unified six-axis summary across families
A compact view of where each family lives on the six axes. Numbers are typical, not bounds.
| Family / route | Min feature | Tolerance | Throughput | Tooling cost | Material waste | Where best |
|---|---|---|---|---|---|---|
| Sand casting | 3 mm | ±1 mm | medium | low | medium | large rough metal parts |
| Die casting | 0.5 mm | ±0.05 mm | very high | very high | low | high-vol Al/Zn |
| Investment casting | 0.5 mm | ±0.1 mm | medium | medium | low | turbine blades |
| Closed-die forging | 1 mm | ±0.2 mm | high | very high | low (near-net) | crankshafts, fasteners |
| Hot/cold rolling | 0.05 mm | ±5 μm | very high | very high | low | sheet, plate |
| Extrusion (metal) | 0.5 mm | ±0.1 mm | very high | medium | low | Al profiles |
| 5-axis milling | 5 μm | ±2 μm | low | low (no tool, but fixturing) | high (chips) | aero pockets |
| EDM | 5 μm | ±2 μm | very low | low | low | hardened steel |
| LPBF (metal AM) | 60 μm | ±0.1 mm | low | none | low | aero brackets, implants |
| WAAM | 2 mm | ±1 mm | very high | low | low | very large metal parts |
| Injection molding | 0.1 mm | ±0.05 mm | very high | very high | low | high-vol plastic parts |
| Extrusion (polymer) | 0.1 mm | ±0.2 mm | very high | medium | low | pipe, film, profile |
| FDM | 200 μm | ±0.2 mm | very low | none | low | prototype, jig |
| SLA | 25 μm | ±0.05 mm | low | none | low | dental, jewelry |
| MJF | 80 μm | ±0.1 mm | low-medium | none | low | nylon production |
| Compression (SMC) | 1 mm | ±0.2 mm | medium | medium | low | auto panels |
| Dry pressing (ceramic) | 0.5 mm | ±0.5% | very high | medium | low | tile, capacitor |
| Tape casting | 10 μm | ±2% | high | medium | low | MLCC, SOFC |
| Slip casting | 1 mm | ±2% | medium | low | low | sanitary ware |
| Binder jet (ceramic) | 50 μm | ±1% | medium | none | low | refractory cores |
| RTM (composite) | 1 mm | ±0.5 mm | medium | high | low | structural carbon |
| Prepreg + autoclave | 0.5 mm | ±0.3 mm | low | very high | low | aero primary |
| Pultrusion | 1 mm | ±0.5 mm | very high | medium | low | constant-section structural |
| Filament winding | 1 mm | ±0.5 mm | high | medium | low | pressure vessels |
8. Recent processing-route shifts (2020–2026)
- Wire-arc additive (WAAM) crossed into large-scale production — RAMLAB’s WAAMpeller (2017) and 3-tonne marine propeller; Cranfield + ESAB; Aussie subs hull-section trials. Build rates 8 kg/hr now compete with forgings on lead-time for one-off thick sections.
- HP Metal Jet S100 (binder-jet steel, 2022 commercial, 2024 mature) hit Volkswagen + GKN automotive-volume parts at ~10× LPBF throughput.
- Carbon DLS (CLIP) dental + footwear (Adidas Futurecraft 4D + Carbon3D); now a real end-use mass-customization route at ~100M parts/yr.
- Continuous fiber 3D printing (Markforged, Anisoprint, Arevo, Continuous Composites CF3D, 9T Labs, Orbital Composites Cosmic, Mantle TrueShape for tooling) — composite parts at LPBF-like price points.
- CMC scaling — GE LEAP engine and GE9X CMC turbine shrouds in serial production; SiC fibers from Hi-Nicalon (NGS) and Tyranno (UBE) supply-limited.
- Geopolymer cement scaling for low-carbon construction — see geopolymer-and-concrete-chemistry-deep.
- Sintering revolution — SPS / FAST in production for transparent ceramics, ultra-fine-grain WC-Co, and HEA sintering (high-entropy-alloys-deep).
- Modal hybrid additive-subtractive (DMG MORI Lasertec, Mazak Integrex, Optomec LENS) — combine DED with milling on one platform for repair + rework.
- Process simulation maturity — DEFORM, Forge NxT, Simufact, MAGMA, ProCAST, ANSYS Additive Suite, Autodesk Netfabb, 3DEXPERIENCE SIMULIA. Full thermal-stress simulation of an LPBF build is now overnight on a workstation.
Adjacent
- Characterization — characterization-methods for SEM/TEM/XRD/EBSD/CT post-process inspection.
- Mechanical properties — mechanical-behavior-of-materials for what process-microstructure does to performance.
- Compositions — alloy-and-superalloy-catalog and polymer-properties-and-applications for the material side.
- High-entropy alloys — high-entropy-alloys-deep for processing nuances unique to HEAs.
- Composites — composite-materials-advanced for the deep composite-processing view.
- Semiconductor process flow — semiconductor-materials-and-process-deep.
- Refractory + thin-film — refractory-and-thin-film-deposition.
- Concrete + geopolymer — geopolymer-and-concrete-chemistry-deep.
- Manufacturing engineering — manufacturing engineering for the production-engineering side.
When to pick what
What's the part?
├─ Metal
│ ├─ One-off / very low volume
│ │ ├─ Large rough → sand cast + machine
│ │ ├─ Complex pocketed → 5-axis milling from billet
│ │ ├─ Lattice / topology-optimized → LPBF or EBM
│ │ ├─ Repair + cladding → DED (LMD or wire-arc)
│ │ └─ Very large (m-scale) → WAAM
│ ├─ Medium volume (100–10k)
│ │ ├─ Net-shape → investment casting
│ │ ├─ High-integrity Al → squeeze cast or thixoform
│ │ ├─ Inconel / Ti → LPBF (light) or isothermal forge
│ │ └─ Small precision → MIM
│ └─ High volume (>10k)
│ ├─ Al/Zn/Mg → die casting
│ ├─ Crankshaft / con-rod / fastener → closed-die forging
│ ├─ Sheet → cold rolling + stamping
│ ├─ Profile → extrusion
│ └─ Small intricate → binder-jet (HP Metal Jet) + sinter
├─ Polymer
│ ├─ Prototype → FDM/FFF, SLA, MJF, PolyJet
│ ├─ Low-medium volume (100–10k) → SLS / MJF (nylon), Carbon DLS (elastomer)
│ ├─ High volume → injection molding (gas-assist if thick/hollow)
│ ├─ Hollow → blow molding (extrusion / injection / stretch)
│ ├─ Large hollow → rotational molding
│ ├─ Constant profile → extrusion
│ ├─ Thermoset filled → BMC / SMC compression
│ └─ Multilayer barrier → co-extrusion blown-film
├─ Ceramic
│ ├─ Tile / capacitor → dry pressing
│ ├─ MLCC / SOFC layer → tape casting
│ ├─ Hollow / complex → slip casting or DLP-ceramic
│ ├─ Honeycomb support / catalyst → ceramic extrusion
│ ├─ Small precision → CIM
│ ├─ Refractory / mold → binder jet + sinter
│ ├─ Full density at low T → SPS / flash sintering
│ └─ CMC turbine component → CVI + PIP route
├─ Composite
│ ├─ Prototype / racing one-off → hand layup
│ ├─ Aerospace primary skin → AFP + autoclave (prepreg)
│ ├─ Aerospace secondary → OOA prepreg
│ ├─ Wind blade → VARTM / infusion
│ ├─ Automotive structural → HP-RTM
│ ├─ Pressure vessel (H₂ COPV) → filament winding
│ ├─ Constant section structural → pultrusion
│ ├─ Auto body panel → SMC compression
│ ├─ Thermoplastic stamp → PEEK/PEKK/PPS stamping
│ ├─ End-use 3D-printed composite → continuous fiber AM (Markforged, Continuous Composites CF3D, 9T Labs)
│ └─ Hot-section turbine → CMC (CVI + melt infiltration)
└─ Semiconductor / thin film
→ see [[Sciences/MaterialsScience/semiconductor-materials-and-process-deep]] and [[Sciences/MaterialsScience/Tier3/refractory-and-thin-film-deposition]]
The single biggest practical lesson 2010–2026 is that break-even quantity drives route choice more than capability does. Almost every modern route can make almost any geometry — the question is at what cost per part. Injection molding wins at 10⁵+; LPBF wins at 1; the band 100–10,000 is where SLS, MJF, MIM, binder jet, RTM, and 5-axis machining all fight. Pick the route whose break-even matches your annual demand, then validate that it can hit your minimum feature + finish + tolerance. Designing for the wrong route is what kills programs — designing for the right route makes them cheap.