The colors of thermal deburring
Die Farben des thermischen Entgratens bei Eisenwerkstoffen
leiten sich aus den verschiedenen
1. Untreated workpiece
2. Workpiece after the first shot with an excess of oxygen
3. Minimization of oxide via stoichiometrical gas mixture (second shot)
4. Finished/cleaned part Washing of TEM deburred workpieces is – depending on the
material – an essential part of the subsequent treatment.
Process capability of materials
Basically, all oxidable metals can be deburred, but
there are limitations for standard materials:
- Magnesium, due to its low ignition temperature as well as of its melting and boiling point, this material tends to further, uncontrollable combustions
- Titanium, because of its very high boiling point (3,535 °C/6,395 °F)
- The same applies to highly heat resisting materials for the aerospace technology (e.g. zirconium)
Generally, all thermoplastics are processable. In this connection, the burr is melted and not oxidized. Only pure thermoplastics are suitable for TEM, the applicability of plastics with glass fiber content is limited. The burr melts a bit more than the fiber glass during deburring so that – examined under a microscope – the edge looks saw-toothed. The roughness of the edge is also noticeable with the fingers. Thermoset does not resist the explosion pressure and bursts due to its brittleness.