Question

An investigation of grain growth in a-brass for various times and temperatures generated the following data:

Temperature (°C)	Time (min)	Average diameter (µm)
600	30	30
600	60	40
700	90	80

1. Determine the original grain diameter and if the grain growth law (d2-d02 = kt, k = 2M_og_b exp(-Q/(RT)), where M_o and g_b are constants for a given material, Q activation energy, and T temperature) applies for this alloy and the original grain size is the same for various temperatures.
2. Determine the activation energy Q.
3. What grain diameter would you predict after 120 min at 500 °C?

Answer 1