Abstract
This paper reports on an investigation conducted to
establish the influence of Wire Electrical Discharge Machining
(WEDM) on the fracture toughness of aluminum 7075-T6511.
The main objective was to determine if WEDM can be used to
introduce a pre-crack into a compact tension specimen instead
of the ASTM E-1820-11 specified fatigue pre-crack method.
Fracture tests were conducted on four specimens which were
pre-cracked using the WEDM technique. The rest of the
fracture toughness evaluation followed the ASTM E-1820-11
guidelines. Results obtained from the experimental data were
found to be inconsistent with the theoretical expectations. The
fracture toughness was found to be significantly dependent on
the effect of the WEDM on the material. The WEDM
introduced a Heat Affected Zone (HAZ) on the surface of the
pre-crack which modifies the fracture behavior of the material.
It was concluded that WEDM is not a viable alternative to
create a pre-crack in a compact tension specimen to perform
fracture toughness testing of aluminum 7075-T6511.