Diffusion in material You are hardening a very thick tool plate made of BCC Fe by...

Diffusion in material

You are hardening a very thick tool plate made of BCC Fe by increasing the carbon concentration in its surface layer by heating the tool in the presence of a C-rich gas (e.g. methane) which maintains a constant C concentration at the surface. A heat treatment at 600 °C for 100 minutes results in a C concentration of 0.75 wt% at a position 0.5 mm below the surface. How long would it take to obtain the same result (i.e. the same C concentration at the same depth) if the heat treatment were conducted at 900 °C. Schematically draw the C concentration profile (i.e. the C composition as a function of the distance from the surface) in the tool plate. At either of the temperatures, does the diffusion rate (measured by the diffusion flux) go up or down with increasing distance from the surface and why?

D₀ = 2 x 10^-6 m²/s and Q_d = 84 kJ/mol

Solutions

Expert Solution

samet mamat answered 1 year ago

Next > < Previous

Related Solutions

If you were using the quadrant streak plate method to plate a very dilute broth culture...

If you were using the quadrant streak plate method to plate a very dilute broth culture (with many fewer bacteria than the broth used for the plate pictured here), would you expect to see single, isolated colonies in quadrant 4 or quadrant 3? Explain your answer.

2. You are an engineer trying to design a capacitor. You have a parallel-plate capacitor made...

2. You are an engineer trying to design a capacitor. You have a parallel-plate capacitor made of two circular metal plates. The radius of each plate is 1 m and they are separated by a distance of 0.1 mm. If the space in between the plates was filled with vacuum, the capacitor would have a capacitance of 0.278 μF but you want to make this capacitor have a capacitance of 1.0 μF. You only have paraffin (K=2.2) and glass (K=5)...

You shine a laser on a plastic prism made from an unknown material and measure the...

You shine a laser on a plastic prism made from an unknown material and measure the angles relative to the normal that the light takes both inside and outside the medium. You make a plot of sin ?inside versus sin ?outside for the plastic object and calculate the slope of best-fit line of your plot to be 0.79365 ± 0.05669. What is the index of refraction of the plastic object? Correct Answer: 1.26 +/- 0.09 How do you get the...

Can a magnetic field sensor be made using semiconductor material? If you say it can be...

Can a magnetic field sensor be made using semiconductor material? If you say it can be done, draw the necessary schemes and explain the theoretical calculations. Discuss which devices or instruments will you use to determine physical quantities (indicate which quantities are you going to find), and how you can determine the magnetic field strength.

Hi Tina. Thanks for getting our discussion off to a great start! You made a very...

Hi Tina. Thanks for getting our discussion off to a great start! You made a very good observation related to comparability across entities! It might be interesting to see how this could apply in practice. Let’s say that we wanted to value the following organizations: Walmart Honda Exxon Ebay Local law firm Class, what challenges might we encounter in comparing the values of such entities?

You need to electroplate a 140-nm-thick zinc coating onto both sides of a very thin, 1.0 cm × 1.0 cm copper sheet.

You need to electroplate a 140-nm-thick zinc coating onto both sides of a very thin, 1.0 cm × 1.0 cm copper sheet. You know that the charge carriers in the ionic solution are divalent (charge 2e) zinc ions. The density of zinc is 7140 kg/m3. How many seconds will it take the zinc to reach the desired thickness?

Hi Max. You made a very interesting point regarding reliability! Anytime we are making computations for...

Hi Max. You made a very interesting point regarding reliability! Anytime we are making computations for the purposes of financial analysis, evaluation, or projections, we are somewhat at the mercy of the accuracy of those input figures. If the figures used for our input are unreliable, then our results could be useless or downright misleading. Class, with that being said, when computing projections or indicators, what responsibility does a given analyst have to confirm or further verify the reliability of...

Hi Archie. You made a very interesting observation in your posting regarding restatement issues with specific...

Hi Archie. You made a very interesting observation in your posting regarding restatement issues with specific statements. It might be interesting to explore this a little bit more. We typically think of the income statement when we hear of a financial restatement, but it’s certainly possible for other statements to be impacted. Let’s examine the statement of cash flows. We know that the change in cash during the period should reconcile with the change that we see in cash between...

Subjects