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Question 7.1: The strain-rate dependence of a zinc alloy can be represente......

The strain-rate dependence of a zinc alloy can be represented by Equation (7.1), with m = 0.07. What is the ratio of the flow stress at \varepsilon = 0.10 for a strain rate of 10³/s to that at \varepsilon = 0.10 for a strain rate of 10^{-3 } /s? Repeat for a low carbon steel with m = 0.01.

\sigma =C\dot{\varepsilon }^m.    (7.1)

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For zinc (m = 0.07),        \sigma_{2}/\sigma_{1}=(C\dot{\varepsilon }m_{2})/(C\dot{\varepsilon }m_{1})=(\dot{\varepsilon }_{2}/\dot{\varepsilon }_{1})^m =(10^3 / 10^{-3 })^{0.07 }=(10^6)^{0.07}=2.63. For steel (m = 0.01), \sigma_{2}/\sigma_{1}= (10^6)^{0.01 } =1.15.

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