Introducing small artificial defect (semi-elliptical surface slit) into test specimen

  Micro defects and nonmetallic inclusions in material are factors affecting material fatigue strength, and have been drawing attention as a subject for study. Recently, test methods using a specimen with an artificial defect are receiving attention to quantitatively evaluate effects of micro defects and nonmetallic inclusions.

  Our laboratory has established technology to machine a semi-elliptical surface slit (an artificial defect). The machining is controlled by small-amplitude pulse of low-peak current.

  The following is an example of possible slit configuration introduced into a specimen.