HWCH6Spring - at the surface with the oxygen in the...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Homework Ch. 6 2 Introduction to Materials Science 6.5 (a) Briefly explain the concept of a driving force. (b) What is the driving force for steady-state diffusion? . 6.6 The purification of hydrogen gas by diffusion through a palladium sheet was discussed in Section 6.3. Compute the number of kilograms of hydrogen that pass per hour through a 5-mm thick sheet of palladium having an area of 0.20 m2 at 500C. Assume a diffusion coefficient of 1.0x10-8 m2/s, that the concentrations at the high- and low-pressure sides of the plate are 2.4 and 0.6 kg of hydrogen per cubic meter of palladium, and that steady state conditions have been attained. 6.12 An FCC iron–carbon alloy initially containing 0.35 wt% C is exposed to an oxygen-rich and virtually carbon-free atmosphere at 1400 K (1127C). Under these circumstances the carbon diffuses from the alloy and reacts
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: at the surface with the oxygen in the atmosphere; that is, the carbon concentration at the surface position is maintained essentially at 0 wt% C. (This process of carbon depletion is termed decarburization.) At what position will the carbon concentration be 0.15 wt% after a 10-h treatment? The value of D at 1400 K is 6.9x10-11 m2/s. 3 Introduction to Materials Science 6.22 The diffusion coefficients for silver in copper are given at two temperatures: (a) Determine the values of D o and the activation energy Q d . (b) What is the magnitude of D at 875 o C? 6.23 Below is shown a plot of the logarithm (to the base 10) of the diffusion coefficient versus reciprocal of the absolute temperature, for the diffusion of iron in chromium. Determine values for the activation energy and preexponential....
View Full Document

Page1 / 2

HWCH6Spring - at the surface with the oxygen in the...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online