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A Preliminary Investigation of Bonding Mechanisms and Microstructure Development of Molding Materials for the Investment Casting Industry.

Steinkamp B; Ramay C; Askeland D
For Reference Only At Bureau Libraries :5 pages
Because of the advantageous refractory and nonwetting characteristics of zircon, an important application for zircon minerals is in the production of investment casting shell molds. Zircon flours and sands often substitute all or partly for silica in the prime coats of the investment shell. Each individual investment casting foundry often employs its unique blend of zircon, silica, and colloidal silica in this application. Backup coats to complete the buildup of the shell are often composed almost entirely of silica-based materials. Because of the mixture of materials in the shells, recovery of the zircon has seldom been attempted, either for reuse as an investment material or for other applications, such as refractory materials. The intent of this research is to understand the phase reactions that occur during the investing process: the burnout, firing, and preheat processes; and the pouring and cooling processes. This study of the bonding mechanisms and microstructures in investment shell materials will suggest methods for reclamation and both foundry and nonfoundry uses for the recovered minerals. A fundamental understanding of the microstructures and how they develop may also lead to the development of new shell consumables that will be more sensitive to reclamation needs, while assuring consistent production of high-quality investment castings.
Document Type
CP; Final Contract Report;
Identifying No.
OFR 39-92
NIOSH Division
Source Name
For Reference Only At Bureau Libraries
Performing Organization
University of Missouri--Rolla
Page last reviewed: December 30, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division