PEEK machining
PEEK is a high-performance (semi-crystalline) thermoplastic with remarkable mechanical, thermal and chemical stability in demanding environments. It retains its properties over long periods at high temperatures, resists chemical corrosion, and certain grades are biocompatible. By working with PEEK, MicroMécanique has expanded its offering beyond hard and technical metals, for lightweight, resistant, insulating parts or special applications where metals are less than ideal.
Examples of products and possible applications
MicroMécanique produces or could produce the following components from PEEK according to its customers’ needs:
- Insulating components for electrical or electronic devices (holders, spacers and insulators).
- Medical parts: external implants, surgical instruments, sterile parts, and even prostheses when the grade is suitably biocompatible.
- Aeronautics and space industry parts: lightweight parts with temperature resistance, low moisture absorption, limited thermal conductivity = good thermal insulation.
- Parts for the chemical or petrochemical industry: valves, seals, seats, components in contact with solvents or aggressive environments.
- Parts subject to moderate wear: bearings, bushings, slides, sliding or moving parts not sustaining extreme friction or abrasion.
- Components in the semiconductor or electronics industry that require minimal degassing, dimensional stability and tight tolerances.
- Prototypes, small series for R&D or for technical/aesthetic parts where the specific performance of PEEK is an advantage.
Properties of PEEK
Below are the main properties of PEEK, and typical values found in the literature:
Property | Description/Typical values |
Continuous operating temperature | Up to approximately 250-260°C depending on grade. |
Glass transition temperature (Tg) | Around 143°C. |
Melting point (Tm) | ≈343°C for pure PEEK. |
Density | ≈1.31-1.45 g/cm³ depending on the grade (unreinforced or reinforced); significantly lighter than metals. |
Tensile strength | Varies depending on grade; for example around 90-120 MPa for unreinforced PEEK and higher for reinforced grades. |
Young’s modulus/stiffness | Grades reinforced with (glass or carbon) fibres have significantly greater stiffness. Reinforced grades have a higher flexural modulus. |
Heat resistance/dimensional stability | Good resistance to thermal expansion, low water absorption and its properties hold well with strong heat conduction. |
Chemical resistance | Excellent: resistant to many solvents, weak acids, bases, aggressive environments, etc. |
Wear/friction/coefficient of friction | Low coefficient, good abrasion resistance in many conditions, especially in suitable grades. |
Biocompatibility | Some medical grade PEEKs are used for external medical devices and implants. |
Machining techniques required/used at MicroMécanique
The following processes and techniques are suitable for precision machining of PEEK:
- CNC turning and milling: widely used, with well-sharpened tools, an appropriate feed rate and speed to avoid overheating, distortion or stress accumulation in the workpiece.
- 5-axis or multi-axis machining for complex parts, special geometries and parts with curved surfaces.
- Microdrilling/thin pieces: possible, but it is important to control heating levels and eliminate chips.
- Dry milling or with light lubrication if medical grade to avoid contamination. Some grades require drying or specific processes.
- Control of internal stresses: annealing/stress relieving after machining or before machining if the material has been subjected to stress (storage, shaping), to avoid subsequent distortion.
- Surface finishing: polishing and deburring to obtain smooth surfaces, particularly for medical or contact applications.
- Dimensional stability: PEEK offers good tolerances, but thermal expansion, humidity variations, etc. must be anticipated.
Would you like to work with PEEK?
Discover its applications
MicroMécanique is able to work with this high-performance material to serve the following sectors:
- Medical equipment and devices, implantology: implants, fixings, instruments and sterile parts.
- Aeronautics and space: lightweight parts exposed to heat or thermal cycling, insulating parts, non-load-bearing but critical structural components.
- Chemicals and petrochemicals: parts in contact with solvents, aggressive fluids and corrosive environments.
- Electronics and semiconductors: insulating parts, substrates, holders, components that must withstand a vacuum or require minimal degassing.
- Projection industry and moderate wear: bearings, slides, sliding parts where weight, friction and durability are key.
- Research & development, prototypes and small series for specific technical needs (reduced weight, thermal performance, chemical performance, etc.).