0.6 and 0.3k Problem 4 1Opts) The concentrations of carbon at the two faces of a...
Problem 700 pts) (e) Compare the response of thermoplastics and thernosets to heati classes of polymers (if any) can be recycled. (b) what is a copolymer? The concentrations of carbon at the two faces of a 12 mm thick plate are 0.6 and 0.3 kg/m' Fe constant. If the preexponential and activation energy are 6x10 m'ls and 80,000 J/mol, Problem 8.d0 pts) The concentrations of carbon at the two faces respectively, determine the temperature at which the diffusion flux is...
plastic
5. Consider the diffusion of water vapor through a polypropylene (PP) sheet 2 mm thick T pressures of H20 at the two faces are 1 kPa and 9 kPa, which are maintained constant. Th permeability coefficient of H2O through PP is 38 x 103 (cm STP)-cm/cm2-s-Pa. Assumin conditions of steady state, what is the diffusion flux, in [(em STP/em-s), at 298 K? Answer:ー-52,10ーフ (cm3 STP)/cm2-S 1.52 10
5. Consider the diffusion of water vapor through a polypropylene (PP) sheet...
No. 5 (20 points) (a) Determine the time necessary to achieve a carbon concentration of 0.30 wt.% at a position of 4 mm into an iron-carbon alloy that initially contains 0.10 wt. % C. The surface concentration is to be maintained at 0.90 wt.% C, and the diffusion coefficient of C is 7.0 x 10-11 m2/sec. (10 points) (b) The diffusion coefficient of Ni in a stainless steel (fcc) is 1 x 1022 m2/sec at 500°C and 1 x 10-15...
Please show work for problems 1-4
1. Calculate the activation energy for vacancy formation in aluminum, given that the equilibrium number of vacancies at 500°C (773 K) is 7.57 x10m3. The atomic weight and density (at 500°c) for aluminum are 26.98 g/mol and 2.62 g/cm, respectively 2. What point defects are possible for Al,0, as an impurity in Mgo? How many Al ions must be added to form each of these defects? 3. A sheet of steel 4.5 mm thick...
Problem 5.10
A sheet of BCC iron 4.9-mm thick was exposed to a carburizing
atmosphere on one side and a decarburizing atmosphere on the other
side at 725°C. After having reached steady state, the iron was
quickly cooled to room temperature. The carbon concentrations at
the two surfaces were determined to be 0.011 and 0.0074 wt%.
Calculate the diffusion coefficient if the diffusion flux is 2.6 ×
10-8 kg/m2-s, given that the densities of
carbon and iron are 2.25 and...
A diffusion couple composed of
two silver– gold alloys is formed; these alloys have compositions
of 98 wt% Ag–2 wt% Au and 95 wt% Ag– 5 wt% Au. Determine the time
this diffusion couple must be heated at 750°C (1023 K) in order for
the composition to be 2.5 wt% Au at the 50 μm position into the 2
wt% Au side of the diffusion couple. Preexponential and activation
energy values for Au diffusion in Ag are 8.5 × 10−5...
Problem 9.43 The 4 m x 4 m horizontal roof of an uninsulated aluminum melting furnace is comprised of a 0.08-m-thick fireclay brick refractory covered by a 5-mm-thick steel (AISI 1010) plate. The refractory surface exposed to the furnace gases is maintained at 1700 K during operation, while the outer surface of the steel is exposed to the air and walls of a large room at 25 0C. the emissivity of the steel is 0.3. (a) What is...
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compare and co describe one industrial application in which steady state diffusion plays an important role, use sketches as needed; (c) An FCC iron-carbon alloy initially containing 0.22 wt% carbon is carburized at an elevated temperature and in an atmosphere wherein the surface carbon concentration is maintained at 1.1 wt% carbon. If after 50.0 hours the concentration of carbon is 0.47 wt% at a position 2.2 mm below the surface, determine...
15 Points In one workshop, five holes (12 mm diameter) need to be drilled in a 50 mm thick steel plate. Three holes are blind with 30 mm deep, while the other two holes are through holes. At the moment there is only one drill available in the workshop with a tool diameter of 12 mm and point angle of 1180. The available tool can achieve a tool life of 1 minute at a cutting speed of 16 m/min using...
Problem 2 Heat Diffusion: A tall wall has a thickness of L = 400 mm and a thermal conductivity of 0.25 W/m-K. One side of the wall is maintained at Ts 80°C. The temperature in the wall varies as a function of position due to internal heat generation. The temperature variation is given as, goL2 where go 10 W/m3. Use this expression to answer the following questions. Assume that the wall temperature is at steady state. A) Find the temperature...