1918 Strain Rate Dependence of Flow Stress of 2017-O Aluminum alloy at Very High Strain Rates

Strain rate sensitivity in FCC metals is known to increase dramatically when the strain rate exceeds about 5×10^3 s^<-1>. In order to evaluate the strain rate sensitivity of a dynamic flow stress of aluminum alloy at very high strain rates, constant strain rate tests and strain rate reduction tests are conducted for 2017-O in a strain rate range from about 1×10^3 s^<-1> to 3×10^4 s^<-1>. The flow stress increases linearly with increasing strain rate itself and the instantaneous strain rate plays a dominant role in the flow stress at very high strain rates. Alloying elements increase a component of athermal stress but have no influenced on the strain rate sensitivity of the flow stress.