(a) Determine the carburizing time necessary to achieve a C concentration of 0.45 wt % at a position 2 mm into of 0.45 wt% at a position 2 mm into an Fe-C alloy that initially contains 0.2 wt% C. The surface concentration is to be maintained at 1.30 wt %C, and the treatment is to be conducted at 1000 C. Use Table 1 for y-Fe. (R= 8.31 j/mol K) Table 2 Table 1. Diffusing Specie ../mol) Z 0.55 0.60 Host Metal DAP/) Interstitial Diffusion Fe (a or BCC) 1.1 X 100 Fe (yor FOCY 23 X 10-5 Fe (a or BCCY 5.0 X 10 Fe (yor FCCY 21 x 10 87.400 148.000 77.000 168.000 N N 0 0.025 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 erf (1) 0 0.0282 0.0564 0.1125 0.1680 0.2227 0.2763 0.3286 0.3794 0.4284 0.4755 0.5205 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.0 1.1 1.2 erf(z) 0.5633 0.6039 0.6420 0.6778 0.7112 0.7421 0.7707 0.7970 0.8209 0.8427 0.8802 0.9103 2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 20 2.2 2.4 2.6 erf(2) 0.9340 0.9523 0.9661 0.9763 0.9838 0.9891 0.9928 0.9953 0.9981 0.9993 0.9998 0.9999 28 (b) Explain the solidification process and burgers vector (curciut) by drawing a figure. Explain what is the relation between points defects and temperature