Masters Theses

Abstract

"The work contained here is a collection of papers dealing with metal/mold interactions in net shaped cast steels. These unwanted interactions lead to surface defects that warrant extensive rework or in extreme cases, scrapped casting. The overall goal of these papers was to understand the mechanisms behind the surface defects that form in investment casting and no-bake casting. Even though the molding media may be different, the underlying goal of understanding why coating breaches occur and identifying approaches to prevent metal penetration and casting surface defects is the same.

The first two papers deal with measurement of factors such as thermal conductivity change of the shell, the mechanisms of condensation and effects of drain angle on the heat of condensation as well as documentation of autoclave and boilerclave conditions. The first of the two papers is an overview of the design of a data acquisition system to measure the aforementioned properties. The second paper contains the collected data, detailed explanations of the results and conclusions.

The third paper is a study of thermal and structure properties of various investment casting waxes. Four foundries submitted commonly molded, filled virgin wax patterns and identically shaped filled reclaimed wax patterns for comparison. These samples and a pure polyvinyl ether wax were analyzed for crystallinity using x-ray diffraction. Additionally, each wax was subjected to differential scanning calorimetry to examine the heat capacity, heat of fusion, melting temperature and glass transition temperature (Tg) for various heating rates. This information is useful when comparing foundry to foundry and when evaluating the efficiency of each foundry's reclamation process.

The last paper is the culmination of several designed experiments on the mechanisms behind burn-in, bum-on and penetration in no-bake molding systems. These designed experiments explore the effects of several process factors such as sand composition, sand reclamation process, molding techniques and coating application on adhering sand defects. It also presents the resulting conclusions based on the outcomes of the various trials"--Abstract, page iv.

Advisor(s)

Richards, Von

Committee Member(s)

Peaslee, Kent D., 1956-2013
Smith, Jeffrey D.

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Metallurgical Engineering

Publisher

University of Missouri--Rolla

Publication Date

Fall 2005

Journal article titles appearing in thesis/dissertation

  • Success of a data acquisition system designed to measure thermal, moisture and pressure profiles in production autoclaves
  • Thermal and moisture characterization during autoclave dewaxing in investment casting
  • Characterization of investment casting waxes as a semi-crystalline material by DSC and XRD
  • Investigation of the causes that lead to burn-in/burn-on in heavy section steel castings

Pagination

xv, 140 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2005 Brandon Lee Kruse, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Subject Headings

Precision castingAutoclavesShell molding (Founding)

Thesis Number

T 8860

Print OCLC #

70135166

Electronic OCLC #

1086394083

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