The influence of work-history on the
r-value has been examined on the pure aluminium and copper sheets having the cubic orientation.
The results obtained are as follows:
(1) The
r-values of the Cu annealed specimens having the cubic orientation have neither texture anisotropy dependence nor strain rate dependence and are expressed by
r=0.95 for the whole strain regions.
(2) On the
r-values of the Cu prestrained specimens pressed under conditions of \dotε=0.666/sec, ε=0.50 and
n=0.336, the
r-values of 0° and 90° directions to the rolling direction are expressed by
r=
e−0.05·\sqrtε. While the
r-values of 0° and 90° directions have no strain rate dependence, but the
r-value of 45° direction shows the strain rate dependence and are expressed by
r=
e0.006·ε
0.27·\dotε
0.02.
(3) The
r-values of the annealed specimens having the cubic orientation have no strain rate dependence and are expressed by
r0=0.60,
r45=0.90 and
r90=0.50 for the whole strain regions.
(4) On the
r-values of the Al prestrained specimens pressed with conditions of \dotε=0.653/sec, ε=0.50 and
n=0.283, the
r-values of 0° and 90° directions to the rolling direction are expressed by
r=1.747·ε+0.239. While, this
r-values of 0° and 90° directions have no strain rate dependence, but the
r-value of 45° direction shows the strain rate dependence and are expressed by
r=3.56·\dotε+0.43·ε+0.118.
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