subject
Engineering, 26.06.2020 16:01 isabua

Dependence of oxidation on the temperature 10 points total The process temperature is an important parameter for the oxide growth process. To get an estimate for the temperature dependence of the Deal-Groove formula, the following considerations can be used. All processes (transport, diffusion and reaction) that are used in the Deal-Groove model are thermally activated. Thus, the dependence on the growth parameters on the temperature T can be estimated by: X(T) = Xpe Xe{A, B, B/A} (5) Here kB = 8.617 x 10-5 eV/K is the Boltzmann Constant and EX is the activation energy for the parameter. X, is the value for the corresponding parameter at T =0 K. Please note that this is not a 'physical activation energy but rather an average/fit parameter for all the physical and chemical thermally activated processes relevant for the process. In the original publication by Deal and Groove, they gave the following parameter sets for dry oxidation: Oxidation temperature in 'C A in um Bin um²/h 1000 0.165 0.0117 1200 0.040 0.045 a)EXct and X, for A, B and B/A a) Use the given values for the parameters A and B in the table above, along with equation ?? to derive the activation energies EXd and zero temperature values X(T = 0 K) for all three parameters A, B and B/A. Then use this calculate the corresponding values of A, B, B/A for the following temperatures: 1000°C, 1200°C, 800°C and 900 °C.
b) Plot estimates for other temperatures 2 points Use the obtained values from the previous sub-task along with the full Deal-Groove model equation for Z:(t) to plot the oxide thickness over time (0-100h) using at least 20 data points each for the following temperatures: 1000°C, 1200°C, 800°C and 900 °C. Assume Zo = Om.

ansver
Answers: 1

Another question on Engineering

question
Engineering, 04.07.2019 18:10
Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.
Answers: 2
question
Engineering, 04.07.2019 18:10
An ideal otto cycle with air as the working fluid has a compression ratio of 8. the minimum and maximum temperatures in the cycle are 300 k and 1340 k. use constant specific heats at room temperature to determine (a) the amount of heat transferred to the air during the heat- addition kj/kg, (b) the thermal efficiency, and (c) the thermal efficiency of a carnot cycle ope limits. process, in rating between the same temperature
Answers: 2
question
Engineering, 04.07.2019 18:10
An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0
Answers: 3
question
Engineering, 04.07.2019 18:10
Aturning operation is performed with following conditions: rake angle of 12°, a feed of 0.35 mm/rev, and a depth of cut of 1.1 mm. the work piece is aluminum alloy 6061 with t6 heat treatment (a16061-t6). the resultant chip thickness was measured to be 1.0 mm. estimate the cutting force, fc. use shear stress of 207 mpa and coefficient of friction on the tool face of 0.6.
Answers: 1
You know the right answer?
Dependence of oxidation on the temperature 10 points total The process temperature is an important p...
Questions
question
Mathematics, 19.05.2020 22:17
question
Mathematics, 19.05.2020 22:17
question
Mathematics, 19.05.2020 22:17
question
Biology, 19.05.2020 22:17
Questions on the website: 13722361