PEEK (Polyetheretherketone) for FDM

Material Profile: PEEK (Polyetheretherketone) for FDM

FDM Engineering Material Technical Report Series

Compiled from manufacturer technical datasheets and peer-reviewed literature

Abstract—PEEK is the canonical ultra-high-performance thermoplastic for additive manufacturing — a semi-crystalline polyaryletherketone with continuous service to 240 °C, intrinsic UL 94 V-0 flammability, exceptional resistance to virtually all chemicals, and mechanical properties comparable to aluminum on a stiffness-to-weight basis. PEEK is used in aerospace, medical implants, oil-and-gas downhole tools, and semiconductor processing. Stratasys VICTREX AM™ 200 is AS9100 aerospace-certified.

Index Terms—additive manufacturing, FDM, PEEK, PAEK, ultra-high-performance polymer, aerospace, medical.

I.  MATERIAL IDENTIFICATION

This section establishes the canonical names and commercial designations under which the material is supplied.

A.  Designation

Trade name: PEEK (generic). Examples: Stratasys VICTREX AM™ 200, 3DXTech ThermaX™ PEEK, 3D4Makers PEEK (Victrex 151G base), 3DGence PEEK.

B.  Full Chemical Name

Poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene), CAS 31694-16-3 — a member of the polyaryletherketone (PAEK) family with two ether and one ketone linkage per repeat unit.

C.  Aliases and Alternative Designations

II.  COMPOSITION AND MOLECULAR STRUCTURE

A.  Empirical Chemical Formula

[-O-C₆H₄-O-C₆H₄-CO-C₆H₄-]ₙ; empirical (C₁₉H₁₂O₃)ₙ.

Fig. 1.  Repeating unit / structural schematic of the polymer matrix.

Fig. 2.  Schematic of the single-phase polymer (no reinforcement).

B.  Composition Breakdown

TABLE I
 COMPOSITIONAL BREAKDOWN OF PEEK (TYPICAL / PER SUPPLIER DATASHEET)

III.  MECHANICAL PROPERTIES — XZ PRINT DIRECTION

In the XZ orientation the tensile load is applied parallel to the deposited rasters; for fibre-reinforced grades this is the strongest orientation because the fibres align preferentially along the extrusion direction.

TABLE II
 MECHANICAL PROPERTIES — XZ ORIENTATION (PEEK)

IV.  MECHANICAL PROPERTIES — ZX PRINT DIRECTION

In the ZX orientation the tensile load is applied perpendicular to the print layers, so failure occurs through inter-layer (Z) bonds. Properties are markedly lower than in XZ — this anisotropy is intrinsic to FDM.

TABLE III
 MECHANICAL PROPERTIES — ZX ORIENTATION (PEEK)

Estimated XZ:ZX UTS ratio ≈ 1.7:1 — among the lowest of FDM polymers, because PEEK's high inherent strength and post-anneal fusion of layer interfaces partially heal print-line discontinuities. Annealing is essential to achieve the property values quoted above.

V.  RECOMMENDED PRINT PARAMETERS

Values summarised below give consensus operating windows from public datasheets. Specific suppliers may differ within ±10 °C; the supplier datasheet always supersedes this table.

TABLE IV
 RECOMMENDED PRINT TEMPERATURE RANGES FOR PEEK

VI.  GLASS TRANSITION TEMPERATURE (TG)

Reported / typical Tg: ≈ 143 – 145 °C.

Above Tg, PEEK's amorphous regions are rubbery, but the crystalline phase (typically 30–35% after anneal) maintains mechanical integrity to near the melting point (~343 °C). Annealing 200 °C × 1–2 h followed by slow cooling is essential.

VII.  HEAT DEFLECTION TEMPERATURE (HDT)

Heat deflection temperature is the temperature at which a standard bar deflects 0.25 mm under a specified flexural load (ASTM D648 / ISO 75).

TABLE V
 HEAT DEFLECTION TEMPERATURE OF PEEK UNDER STANDARD TEST LOADS

VIII.  DISTINGUISHING CHARACTERISTICS AND STANDARDS

A.  Multi-domain certifications

Stratasys VICTREX AM™ 200 carries AS9100 (Aerospace Quality Management System) certification. Standard PEEK is biocompatible per ISO 10993, accepting USP Class VI use; sterilisable by autoclave (134 °C × 30 min), gamma irradiation, and ethylene oxide; and is listed in ASTM F2026 (PEEK for surgical implants). UL 94 V-0 is intrinsic.

B.  Universal chemical and thermal resistance

PEEK is essentially insoluble in any common solvent and resistant to all hydrocarbon fuels, hydraulic fluids, and de-icers; acids; alkalis. Continuous service to 240 °C; short-term excursions to 310 °C; melting point 343 °C.

C.  Mechanical and fatigue resistance

Among the most fatigue-resistant thermoplastics — used for high-cycle parts in jet engines, oil-and-gas downhole tools, and orthopaedic implants. Wear and creep resistance are exceptional.

D.  Print difficulty

PEEK is the most difficult conventional FDM polymer to print successfully. Active heated chamber (90–160 °C), nozzle temperatures > 350 °C, post-print annealing, and meticulous moisture control are all mandatory. Capital cost is high (typical industrial PEEK printer > USD 50k).

IX.  REPRESENTATIVE APPLICATIONS

PEEK is typically deployed in the following applications:

1)  Aerospace flight-rated brackets: Lightweight cabin and engine-bay structural fittings; FST + chemical compliance.

(Source : Stratasys)

2)  Medical implants and surgical instruments: Spinal cages (FDA-cleared as ISO 10993 / USP Class VI), trauma fixation, sterilisable instrument handles.

3)  Oil-and-gas downhole tools: Seals, bearings, instrumentation parts in 200 °C / 70 MPa downhole environments.

4)  Semiconductor manufacturing equipment: Wafer carriers, end-effectors that must not contaminate or out-gas at process temperatures.

5)  Automotive racing / motorsport: High-temperature engine and brake-system components.

Photographs of representative parts in these applications are not reproduced here for copyright reasons; the table below provides direct manufacturer / case-study URLs where original imagery and project descriptions can be viewed.

TABLE VI
 SUGGESTED IMAGE / CASE-STUDY SOURCES

X.  REFERENCES

[1]  Stratasys / Victrex, “VICTREX AM™ 200 Material Data Sheet,” 2023.

[2]  3DXTech, “ThermaX™ PEEK Datasheet,” 2024.

[3]  AS9100D, Aerospace Quality Management System, SAE / IAQG.

[4]  ASTM F2026, “PEEK Polymers for Surgical Implant Applications,” ASTM.

[5]  ISO 10993, “Biological evaluation of medical devices,” ISO.

[6]  S. Berretta et al., “Processing-structure-property relationships of FDM PEEK structures,” Compos. Sci. Tech., 2022.

[7]  ASTM D638-14; ASTM D256-10; ASTM D648-18; UL 94, 2018.