アルミニウムおよびアルミニウム-マグネシウム合金の強度の温度およびひずみ速度依存性

抄録

The effects of temperature and strain-rate on the strength of polycrystalline pure aluminium and on that of aluminium-magnesium alloy have been investigated within the range of temperature from -195 to 450°C and strain-rate from 10^-4 to 3×10²/s.
The test results have been studied from the standpoint of the thermally activated deformation theory. The parameter Z=εexp(H_t/R.T.) (ε is the strain-rate, H_t the apparent activation energy, R gas constant and T the absolute temperature) is effective in prescribing the flow stress in two limited temperature ranges (The intermediate temperature range and the high temperature range) up to ε=10∼50/s.
In the case of pure aluminium, the value of the apparent activation energy H_t increases with the increase of strain (H_t=6600∼19000cal/mol for ε=5∼20%) in the intermediate temperature range (-20∼80°C) and is nearly constant (H_t=34000∼32000cal/mol) in the high temperature range (250∼450°C), while in the case of aluminium-magnesium alloy, H_t is nearly constant in the intermediate temperature range (-20∼80°C) and also in the high temperature range (350∼450°C) (H_t=9000∼12000cal/mol and 42000∼39000cal/mol respectively).