A computer model was constructed and run to predict the thermal history of a
Stellite alloy investment casting prone to the formation of microporosity. The thermal
history of the casting was utilized to calculate the thermal gradient at a specified
temperature, the rate of cooling during solidification, and the solidification velocity.
These parameters were combined in a manner consistent with the formulation of two
different criteria (Niyama and L.C.C. criteria) used to predict porosity. The Niyama and
L.C.C. criteria successfully predicted the distribution of porosity found in the actual
investment casting. Several new casting configurations were designed and modeled on
computer until a configuration was constructed that predicted very little or zero porosity
in the problematic areas. A new casting configuration, similar to the one designed in this
study, was designed and cast by the industrial sponsor. The computer simulation of the
casting configuration by the industrial sponsor predicted a small pocket of microporosity.
Upon examination, some microporosity, consistent with the predictions by the model,
was discovered. The finite element modeling software (ProCAST™) and the Niyama and
the L.C.C. criteria served as excellent tools for predicting porosity in Stellite alloy
castings. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/5877 |
| Date | 05 1900 |
| Creators | Hermesmann, Christopher Marc |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Format | 10234608 bytes, application/pdf |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
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