HOW FIRING TIME AND Temperature Affect Investment Shells

The investment casting process commonly is used to produce near-net shape castings, especially with complicated geometries and thin sections. Investment shells typically are fired at elevated temperatures after dewaxing but before the casting process. This is to combust the residue wax pattern as we...

Full description

Saved in:
Bibliographic Details
Published inModern Casting Vol. 108; no. 9; pp. 30 - 33
Main Authors Wooley, Madison, Vogel, Scott, Pugh, Wayne
Format Trade Publication Article
LanguageEnglish
Published Des Plaines American Foundry Society 01.09.2018
Subjects
Burning time
Casting
Castings
Coarsening
Cooling
Dewaxing
Firing
Grain
Heat conductivity
High temperature
Investment casting
Mechanical properties
Near net shaping
Physical properties
Sintering
Solidification
Temperature
Thermomechanical properties
Online AccessGet full text

Cover

More Information
Summary:The investment casting process commonly is used to produce near-net shape castings, especially with complicated geometries and thin sections. Investment shells typically are fired at elevated temperatures after dewaxing but before the casting process. This is to combust the residue wax pattern as well as sinter the shell to improve the shell strength for subsequent casting operation. However, different firing temperatures and times can have a significant impact on the thermo-mechanical properties of the investment shells. Sintering and coarsening are kinetic driven processes; consequently, time and temperature play an important role on controlling the kinetical perspectives. When firing the shells at relatively low temperatures (less than 1,112F [600C]) for a shorter period of time (one hour), sintering and coarsening are not significant. With increasing amount of time and temperature, the sintering and coarsening are more rapid, resulting in higher shell strength as well as coarser grains.
ISSN:0026-7562
2376-4430