Abstract
The dependences of stretch-formability on crystallographic orientation and work hardening exponent n for metal sheets were investigated. The results showed that in aluminium single crystal plates stretch-formed the (100) oriented single crystal sheet has the best stretch-formability. Therefore copper sheets with various amounts of the (100)[001] orientation were stretch-formed and the effect of the (100)[001] orientation on the stretch-formability was studied.
On the other hand, brass and aluminium sheets annealed at various temperatures were stretch-formed and the contribution of work hardening exponent n to the stretch-formability was studied. The results obtained are summarized as follows:
(1) There is little effect of the crystallographic orientation on the stretch-formability.
(2) Stretch-formability is nearly independent of strain ratio r.
(3) Stretch-formability has little bearing on the observed values of work hardening exponent n at 10% strain, but it is considered that work hardening exponent at fracture represents the stretch-formability.
(4) Elongation is closely related to the stretch-formability; the more the material is elongated in tension, the more excellent is it in strech-formability.
