(a) From the curves shown in Figure and using Equation 10.18, determine the rate of recrystallization for pure copper at the several temperatures.

(b) Make a plot of ln(rate) versus the reciprocal of temperature (in K???1), and determine the activation energy for this recrystallization process. (See Section 5.5)

(c) By extrapolation, estimate the length of time required for 50% recrystallization at room temperature, 20°C (293K).

Transcribed Image Text:

100 80 135°C/ 119 C 113°C 102°C 88°C 43'C 60 40 20 102 104 10 Time (min) (Logarithmic scale) (10.18) rate = fo5