Question

The diffusion coefficients for carbon in nickel are given at two temperatures:

T(˚C)	D(m2/s)
600	5.5 × 10-14
700	3.9 × 10-13

(a) Determine the value of D_0.
(b) Determine the value of Q_d.
(c) What is the magnitude of D? at 820˚C?

Answer 1

We are given with diffusion coefficients of Carbon and Nickel at different temperatures

D₁ = 5.5 × 10^-14 m²/s D₂=3.9 × 10^-13m²/s

T₁ = 600 ^oC = 873 K T₂=700 ^oC=973 K

b)

Relation between D and Q is given by

Let us plug in the values so we can get two equations

subtract 2 from1

-----------------------------------------------------

Let us plug in the values now

a)

Now let us plugin Qd value in 1 and solve for D_o

D_o=1.06x10^-5 m²/s

C)

Magnitude of D at 820 ^oC

Using the same realtion but change in T value

Now T = 820 + 273 = 1093 K

D=2.56x10^-12 m²/s