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· Web viewPROBLEM SET I I 1-) How can you classify diffusion based on the mass transport...
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AssignmentDate: 10.03.2015 Return Date: 17.03.2015 PROBLEM SET II 1-) How can you classify diffusion based on the mass transport mechanism? 2-) Calculate the equilibrium number of vacancies in 1 m 3 of Al at 727°C (or 1000°K). (ρ=2.7 g/cm 3 ; A Al = 27 g/mol; Q V =1 eV/atom; N A = 6,02x10 23 atoms/mole) 3-)A sheet of steel 2.5 mm thick has nitrogen atmospheres on both sides at 900°C and is permitted to achieve a steady-state diffusion condition. The diffusion coefficient for nitrogen in steel at this temperature is 1.2 × 10 -10 m 2 /s, and the diffusion flux is found to be 1.0 × 10 -7 kg/m 2 s. Also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 2 kg/m 3 . How far into the sheet from this high-pressure side will the concentration be 0.5 kg/m 3 ? Assume a linear concentration profile.
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Transcript of · Web viewPROBLEM SET I I 1-) How can you classify diffusion based on the mass transport...
AssignmentDate: 10.03.2015Return Date: 17.03.2015
PROBLEM SET II
1-) How can you classify diffusion based on the mass transport mechanism?
2-) Calculate the equilibrium number of vacancies in 1 m3 of Al at 727°C (or 1000°K). (ρ=2.7 g/cm3 ; AAl= 27 g/mol; QV=1 eV/atom; NA= 6,02x1023 atoms/mole)
3-)A sheet of steel 2.5 mm thick has nitrogen atmospheres on both sides at 900°C and is permitted to achieve a steady-state diffusion condition. The diffusion coefficient for nitrogen in steel at this temperature is 1.2 × 10-10 m2/s, and the diffusion flux is found to be 1.0 × 10 -7 kg/m2s. Also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 2 kg/m 3 . How far into the sheet from this high-pressure side will the concentration be 0.5 kg/m 3? Assume a linear concentration profile.
