50 40 boltzmann matano ao ni interface 30 20 10 10 15

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Unformatted text preview: 20 10 10 15 20 25 30 35 40 45 50 Slice No. Results, x Ni 0.20 0.30 0.40 dc dx -0.283 -0.199 -0.139 1 c2 c1 xdc 3.3525 10-3 3.8415 10-3 2.6415 10-3 D( xNi ) / cm2 s1 1.48 10-9 1.19 10-9 5.72 10-10 (b) x kt1/2 ( x = distance between B-M interface and original interface) d x k x 1/2 Thus v dt 2t 2t x (1.5)(0.003) v 0.011107 cm / s 6 2t (2)(2.07 10 ) (Markers found at xNi =0.30(# of slice=23.5) dx v ( DNi DAu ) Ni dx x D x D D Ni Au Au Ni xNi 0.3, xAu 0.7 dxNi 1.98 cm1 , D 1.19 10 9 cm 2 / s dx 1.10 109 ( DNi DAu )(1.98) DNi 1.10 109 DAu 1.98 1.19 10 9 (0.3) DAu (0.7) DNi 1.10 10 9 (0.3) DAu (0.7) DAu 1.98 1.10 109 10 2 DAu 1.19 109 (0.7) 8.0110 cm / s 1.98 9 1.0110 10 9 2 DNi 8.0110 1.3110 cm / s 1.98 4. Assume molar volume = const. Thus C total C A C B cons tan t (a) When the diffusivity is a function of the concentration, Fick’s 2 nd law is expressed as, 2 ~ ~ C B ~ C B ~ 2 C B C B D ~ 2 C B C B D D D D t x x x 2 x x x 2 x C B I.C. : C B ( x,0) 0.072 mol / cm 3 ( x 0) 0 mol / cm 3 ( x 0) B.C. : assume infinite system : C B (, t ) 0 C B ( , t ) 0.0 7 2 mol / cm 3 This i...
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This document was uploaded on 11/26/2013.

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