1. In the Grain Boundary Nucleation of aa phase to develop 5 phase, the optimum embryo...
1. In the Grain Boundary Nucleation of aa phase to develop 5 phase, the optimum embryo shape should be that which minimizes the total interfacial energy. The optimum shape will consequently be abbuted spherical caps as shown in the following figure, which given by Cos 0 = Yaal 2 Yap sle)-5,2+011-00 X1 cosey = 0 208 Yap Yal a) Calculate the 8 ini figure aboves if the Yaa is between 450-600 m) m 2 and Yep is between 600-700 m] m (Please decide one value of y value by your own in their range ). b) Evaluate the magnitude of the shape factor S(e) for this nucleus. c) What is the type of this nucleation? Is it Homogeneous or heterogeneous nucleation? Explain your answer. d) What is the effect of the value S(0) in question b aboves to this nucleation process??