Fracture Toughness Testing of Bi-Material Joints with High Strength Mis-Match
SourceThis paper deals with the influence of strength mis-match on CTOD (δ5) R-curves obtained from homogeneous and electron beam (EB) welded bimaterial CT and SENB specimens of two aluminium alloys. The R-curves of metal-metal bimaterial specimens are compared with the R-curves of each alloy to determine the effect of strength mismatch on the locally measured CTOD (δ5) fracture toughness properties. The homogeneous specimens of two different aluminium alloys, namely 2024-FC and 2024-T351 with yield strengths of 80 and 360 MPa respectively, as well as EB welded bi-material 5 mm thick CT and SENB specimens (a/W=0.15 and 0.5) have been tested at room temperature. The local CTOD (δ5) fracture toughness measurements on such composite specimen configurations produced generally strength mis-match and geometry independent R-curves.