Master of Science (MS)
Mechanical and Aerospace Engineering
cryogenic, distortion, quench, residual, stress, uphill
Mechanical engineering; Aerospace engineering; Design
Parts machined from relatively large thickness cross sections can experience significant deformations from high residual stresses that develop in the part during the heat treatment used to form the aluminum alloy. Uphill quenching is a process that can create a part with low residual stress and stable dimensions when the process is controlled properly. The uphill quenching process involves a solution heat treat, quench, cool to liquid nitrogen, steam blast, and then age to final temper.
In this thesis two parts were modeled using ANSYS. The first part underwent the uphill quench process in the rough machined state. The second part was modeled in the stock material shape and only underwent a solution heat treat, quench, and age to final temper. After the residual stress in the second part was predicted the excess material was removed by killing the associated elements and the deformation of the final machined part was predicted. For both parts analyzed measurements were made and compared against predictions with fairly good results.
Jones, Robert Michael, "Prediction of Residual Stress and Distortion from Residual Stress in Heat Treated and Machined Aluminum Parts" (2014). Master's Theses. 4423.