Damage mechanisms and fracture toughness of GlidCop (R) CuAl25IG0 copper alloy

Crack nucleation and growth behaviour are important parameters in deciding about the applicability of the dispersion strengthened copper alloy CuAl25 in components such as the first wall and divertor in ITER. The effective st rain to fracture of notched tensile specimens decreased with increasing str ess state triaxiality and with increasing temperature at constant constrain t level following the Rice and Tracey model for void growth. in three point bend tests, the strain for stable crack initiation decreased significantly with increasing temperature. The CuAl25 alloy failed by a ductile microvoi d mechanism where extensive void nucleation occurred at very low strains at grain boundaries with increasing stress state triaxiality. At elevated tem peratures the fracture surface morphology changed from microvoid to intergr anular fracture in three-point bend tests. (C) 2000 Elsevier Science B.V. A ll rights reserved.