CJ Enterprises, a division of Bowyer Engineering

CJ Enterprises provides bespoke Micro EDM notching services for Ultrasonic and Eddy Current NDT inspection standards.

Notches are defined in the following classifications:

• Axial or Longitudinal Notch
  A sink notch of 100 to 250 microns wide, which runs along the length of a flat plane, where a standard electrode can be utilised.

• Transverse or Circumferential Notch
  A sink notch 100 to 250 microns wide, which runs
  along a varying plane and could require the
  manufacture of custom / shaped electrodes.

• Micro Notch
  A sink notch less than 1.5 mm long and 100 microns or less wide.

• Internal Notching
  The scope of internal notching is controlled by
  electrode access but includes all other notch and hole categories.

• Shape/ Hole Sinking
  A shape or hole, down to 150 microns diameter.

• Micro Notching to an Ultrasonic Response
  A notch meeting the definition of a Micro Notch.
  With the added capability of meeting a specified
  ultrasonic dB response.

Applications and background:

NDT (non destructive testing) using Ultrasonic, Eddy Current, Radiography etc, to evaluate the presence of discontinuities,(appearing as flaws, voids, and cracks etc) requiring artificial defects of known size, shape and orientation (in the form of notches / holes) placed into reference pieces, in order that detection / sizing of the NDT process can be assessed.
The more accurately the notch can replicate the shape, size and orientation of the defects to be located, the better the detection rate of significant defects. This also results in fewer parts being rejected, as a result of over testing.
Micro notches or fissures can also be placed on parts to seed corrosion on accelerated ageing tests.