APPLICABILITY OF INDENTATION TESTS TO ASSESS DUCTILITY IN THE HOT-ROLLING OF ALUMINUM-ALLOYS

Partial-width indentation tests (PWIT), secondary tension tests (STT) and laboratory-scale rolling tests were conducted on AA5182 and AA7075 alloys at temperatures of from 300 to 560 degrees C. The PWIT was fou nd unsuitable, but the reduction of area in the STT proved, however, a sensitive measure of ductility. For a given temperature, the ductilit y decreased rapidly with increasing strain rate. In rolling, edge tape r had an effect, but temperature was the primary factor controlling fr acture. When the indentation speeds in the STT were chosen to give the same strain rates as in rolling, the agreement between the results of the two tests was very good. The secondary-tension test is thus suita ble for exploring the ductility of aluminium alloys under conditions r elevant to industrial processes. (C) 1998 Elsevier Science S.A.