•You are case-hardening a tool made of BCC (α) iron in the presence of a carbonaceous material. A heat treatment at 600 oC for 100 minutes results in a carbon concentration of 0.75 wt% at a position 0.5mm below the surface. How long would it take to obtain the same concentration at the same position if the heat treatment were conducted at 900 oC?   x12/D1t1=  x22/D2t2 Arrhenius equation: D=D0e^(〖-Qd〗∕RT) Qd = Activation energy of diffusion D0 = Pre-exponential diffusion factor R = gas constant = 8.314 J/(mol*K) Use the Arrhenius equation to calculate D1 and D2.   Calculate the time to satisfy the problem statement.

Q: ..An experiment is conducted to determine the variation of the diffusion coefficient as a function…

A: Answer: The value for the activation energy Qd (eV/atom) based on the experimental data is 0.232…

Q: The mass fraction of eutectoid cementite in a hypereutectoid iron-carbon alloy (just below its…

A:

Q: 900 1600 800 (a) A+F 1400 (a) 700 |(c) (c) A + P P 1200 600 (c) A + B 1000 500 (c) A (b) 800 50% 400…

A: we have  (a)   The final composition will consist of proeutectoid ferrite and martensite.

Q: An FCC iron–carbon alloy initially containing 0.35 wt% C is exposed to an oxygen-rich and virtually…

A: Given: D=6.9×10-11m/2s C0=0.35% Cs=0% Cx=0.15% t=15h or 54000s

Q: A 1020 steel contains 0.20% carbon is carburized by a source that maintains a surface carbon content…

A: Given that, Carbon content at surface, Cs=2 %CInitial carbon content,  Co=0.2 % CCarbon content at a…

Q: Determine the activation energy for vacancy formation in aluminum, if the equilibrium number of…

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Q: Diffusion of carbon into the surface of BCC steel at 600oC for 10 hours results in a carbon…

A: Fick's law of diffusion states that the molar flux of the substance due to diffusion is always…

Q: Using the following table, draw a melting point diagram and estimate the eutectic temperature and…

A: Given data To  Draw a melting point diagram Estimate the eutectic temperature and composition

Q: Q3: With a moderately agitated water, a cylindrical piece of steel with 80 mm diameter is to be…

A: Given data: -  The diameter of the cylindrical piece is D = 80 mm. The hardness of the surface and…

Q: Q2) A steel gear is needed to be improved by increasing the carbon content within an outer surface…

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Q: Problem 1. A sheet of BCC iron 1 mm thick was exposed to a carburizing gas atmosphere on one side…

A: Given:Carbon concentration, Cc=0.012 % and 0.0075 %T=725o CDiffusion flux=1.4×10-8 kg/m2-s

Q: At approximately what temperature (in Kelvin) would a specimen of an alloy have to be carburized for…

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Q: 8.) A steel plate has been heat treated and carburized for 8-h duration. This treatment raised the…

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Q: To increase hardness of steel gear, it was carburized at 1040°C by introducing 1.5%C at its steel…

A: According to Fick's law, the concentration gradient of a composition is equal to the molar flux…

Q: For a steel alloy it has been determined that a carburizing heat treatment of 16 h duration at 763°C…

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Q: 1200 Liquid B+L 1000 a+L 28% 800- 780°C (Ag) (Cu)' 600 a +B 400 200 0- 10 20 30 40 50 60 70 80 90…

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Q: A 6061-T4 aluminum alloy is to be used to make a thin-walled cylindrical canister in which…

A: Thin walled cylinders experience two types of stresses: Longitudinal stress Circumferential stress…

Q: Caldie steel will be nitrided at a temperature of 520°C. By using Table 1, determine the nitrogen…

A: Diffusion is the movement of molecules in the presence of a concentration gradient. The molecules…

Q: For a steel alloy it has been determined that a carburizing heat treatment of 11.3 h duration will…

A:

Q: The mass fraction of eutectoid cementite in a hypereutectoid iron-carbon alloy (just below its…

A:

Q: 5.) A steel plate has been heat treated and carburized for 8-h duration. This treatment raised the…

A: Given data: The locations at which the concertation achieved, x1 = 2.5 mm x2 = 4.5 mm Time (t1) = 8…

Q: For a steel alloy it has been determined that a carburizing heat treatment of 18 h duration at 885°C…

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Q: At approximately what temperature (Kelvin) would a sample of an alloy have to be carburized for 1.8…

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Q: A 0.001 in. BCC iron foil is used to separate a high hydrogen gas from a low hydrogen gas at 650 °C.…

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Q: An iron-carbon alloy initially containing 0.240 wt% C is exposed to an oxygen-rich and virtually…

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Q: An aluminum cup contains 225 g of water and a 40-g copper stirrer, all at 27°C. A 481-g sample of…

A:

Q: Q3) A steel gear is needed to be improved by increasing the carbon content within an outer surface…

A:

Q: To increase hardness of steel gear, it was carburized at 1040°C by introducing 1.5%C at its steel…

A:

Q: At approximately what temperature (in Kelvin) would a specimen of an alloy have to be carburized for…

A: Given Data: The value of D0=1.4×10-4 m2/s. The value of Qd=147 kJ/mol. The time is t1=2.5 h and…

Q: Determine the treatment temperature (°C) necessary to achieve a carbon Formula concentration of 0.60…

A: Calculate the diffusion after 9 hours. Cx-C0Cs-C0=1-erfx2Dt0.60-0.201-0.20=1-erf0.75×10-3 m2D9×3600…

Q: Consider de-oxidation by the addition of ferromanganese (60 percent Mn) to molten steel at…

A: When the steel is partially deoxidized with magnese,then the iron also participates in the reactions…

Q: For alloys of two hypothetical metals A and B, there exists an a, A-rich phase and a b, B-rich…

A: Solution: The mass fraction of α phase for the first alloy is given by: Here, Wa1 = 0.60…

Q: The microstructure of an iron-carbon alloy consists of pro-eutectoid cementite and pearlite; the…

A: Solution:

Q: 3. A BCC iron alloy containing 0.05 wt% C is carburized at 1050°C such that the carbon concentration…

A: (a) Write the given data. cx=0.5%  x=2 mm cs=1.5%co=0.05% T=1050°C Here, cx is the carbon percentage…

Q: 1. What are the point A and point B meaning? Please explain in detail and write the reaction…

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Q: The microstructure of an iron-carbon alloy consists of proeutectoid ferrite and pearlite; the mass…

A:

Q: After entering Cs, C0 and Cx into the LHS of Fick's second law equation, what does erf(z) equal to?…

A: The value of z is written as, Then, Non-steady state diffusion equation, Substitute the given…

Q: For alloys of two hypothetical metals A and B, there exist an α, A-rich phase and a β, B-rich phase.…

A:

Q: An FCC iron-carbon alloy initially containing 0.10 wt% C is carburized at an elevated temperature…

A: Find the error function using Fick’s second law.

Q: Two pieces of the same aluminium alloy were Precipitation Hardened; one by Natural Aging (25°C) and…

A: The activation energy is calculated as: Q=1.987T1T2T2-T1(2.303logt1t2cal/mol here, T1 = Room…

Q: An FCC iron–carbon alloy initially containing 0.25 wt% C is carburized at an elevated temperature…

A: Given X = 5 × 10-3 mm t = 55 h Co = 0.25 Cx = 0.35 Cs = 1 To find Treatment temperature

Q: Diffusion of carbon into BCC iron for 12 hours at a temperature of 500 °C results in a carbon…

A: Given: Carbon concentration at temperature 500 °C for 12 hours is  0.2 wt% at depth of 2 mm.

Q: 1. You have ice at 263 K (-10.0 °C) and 1.0 atm. Whatvcould you do to make the ice sublime? 2. A…

A: Given,  Phase diagrams of ice and Carbon dioxide .

Q: Below is shown the isothermai transrormation aiagram for a 0.45 wt% C iron-carbon alloy. List the…

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Q: Q10. The diffusivity of copper atoms in the aluminum lattice is 7.5 x 10exp- 13 m2/s at 600 °C and…

A: To Find :  The activation energy KJmol   Given :  at the temperature T=600°C diffusivity of copper…

Q: At approximately what temperature (in Kelvin) would a specimen of an alloy have to be carburized for…

A: Given data: Activation energy per mole, Qd = 156 kJ/mol. Pre-exponential, Do = 3.7×10-5 m2/s.…

Atomic diffusion in solids

In material science, diffusion can take place in solid, liquid, and gases. In solids, atomic diffusion can take place with the help of thermally activated and randomly vibrating atoms. The atomic diffusion in solids is complex and very slow in comparison to atomic diffusion in liquids and gases because the interatomic distance between the atoms is smaller in solids as compared to liquids and gases.