Homework 4
.pdf
School
University at Buffalo**We aren't endorsed by this school
Course
MAE 381
Subject
Aerospace Engineering
Date
Jan 8, 2025
Pages
2
Uploaded by GeneralRavenMaster1153
MAE381 Engineering Materials Fall 2024 Homework 4: Diffusion –16 pointsName: ______________________________ Last 4 digits Student ID: _____________ 1)Find the diffusion flux of carbon through an iron plate if the steady state concentrations beneath the carburizing surface are 0.5 kg/m3and 1.25 kg/m3at 10mm and 8mm respectively. Assume a diffusion coefficient of 2.9 x 10-11m2/s. (4 points) 2)You are planning to case harden a gear by increasing the carbon content in the outer layer, but first need to determine the diffusion coefficient; the gear is made from low-carbon steel (assume BCC iron). What is the diffusion coefficient if you plan to case harden the gear at 550°C? (4 points)
MAE381 Engineering Materials Fall 2024 3)Nitrogen from a gaseous phase is to be diffused into pure iron at 600°C; initially the iron does not contain any nitrogen. The surface concentration is maintained at 0.25 wt% N and the diffusion coefficient for nitrogen in iron at 600°C is 1.22 x 10-11m2/s. What will the concentration be 0.5mm below the surface after 20 hours? (8 points)