ZCC Cutting Tools Europe

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Bernd Heinermann Manager Product Management & Application Engineering


Non-metallic Materials

The Challenges of Machining Non-metallic Materials

Non-metallic materials are all materials that do not contain metal in their material matrix. The most important non-metallic materials for industrial applications include plastics, glass, and ceramics. They belong to the ISO X group. Carbon fiber, glass fiber, and, to a more limited extent, Kevlar fiber reinforced plastics (CFRP, GFRP, and KFRP) are highly popular as manufacturers seek to lower the weight of their vehicles in an effort to conserve resources. To create each of these materials, fibers are embedded in a plastic matrix. In the next step, pressed components are made from the base material.
Non-metallic materials – from plastics to ceramics

It has been possible to replace numerous metal parts with plastic components as part of efforts to reduce the weight of electric vehicles and develop more fuel-efficient aircraft. Composites like CFRP or GFRP excel in terms of their high mechanical stability and low specific weight. As a general rule, however, non-metallic components have to be machined before they can be used. This also applies to ceramic components made of zirconium dioxide used in dental prostheses.

Here is a short list of non-metallic materials that are difficult to work:

  • Kevlar: Kevlar is a brand name of DuPont that refers to a material spun from aramid fibers (aromatic polyamide). The main advantages of the material are the high tensile strength of its densely packed fibers and its high impact strength. The material is quite light and highly vibration-absorbent, making it suitable for use in components subject to impact and shock. When machining KFRP, there is a risk of delamination. This involves fraying of the cut edges, causing damage to the part. Conversely, due to their abrasive effects, the fibers wear down cutting tools if they are not specifically designed for this purpose.
  • CFRP: CFRP is approximately four to five times stronger and lighter than steel. The fibers are embedded in thermoset (not re-fusible) or increasingly thermoplastic (re-fusible) plastic. Another property of CFRP is high fatigue resistance. The material is used in beams and body parts in the automotive, aerospace, and medical equipment sectors. Delamination and high abrasiveness are other issues to consider when machining the material.
  • GFRP: Glass fibers are embedded in plastic to create this composite material. GFRP is relatively stable and less expensive than CFRP. As with CFRP, issues include delamination and the abrasive effects on the cutting tool.
  • Zirconium: Zirconium is a mineral. It is used in the form of zirconium dioxide, or zirconia, in many areas of dentistry, such as in the production of implants, dental crowns, root posts, and overdentures. Heavy tool wear is an issue when machining this extremely hard material.

As you can see, machining non-metallic materials poses a number of unique challenges. There is a high risk of delamination with fiber reinforced plastics, especially when the tool is plunged in and out, which takes the form of fraying and splintering. Conversely, ceramic-like materials such as zirconia cause tool wear. But with the high-quality cutting tools from ZCC-CT, it is possible to overcome these material-specific challenges encountered in milling, turning, and drilling operations.

ZCC Cutting Tools Europe

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