Microwave processing of MIM preforms

Abstract

A method of producing a metallic component includes: providing a mixture of a metallic powder and a binder; melting the binder and forming the mixture into a preform in the shape of the component; removing a majority of the binder from the preform; and heating the preform with microwave energy to remove the remainder of the binder and to sinter the metal powder together to form the component. The component may be formed as an individual component or continuously.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates generally to sintered metallic components and more particularly to components sintered by microwave heating. [0002] Metal Injection Molding (“MIM”) is a known process in which a fine metallic powder is mixed with a plastic binder and extruded to a desired shape using plastic molding equipment. The resulting preform is washed to remove a large portion of the plastic from the powder. Subsequent sintering consolidates the preform to form a finished component. [0003] Prior art methods of sintering for MIM preforms require furnace heat treatment at temperatures capable of causing the metal powders to sinter together to make the preform mechanically strong enough for further processing. This is a time consuming process that results in a non uniform product due to the heating process being “from the outside in”, meaning the outer portion of the preform gets more time at high temperature and can sinter earlier causing voids to be tra...

AI Technical Summary

Problems solved by technology

This is a time consuming process that results in a non uniform product due to the heating process being “from the outside in”, meaning the outer portion of the preform gets more time at high temperature and can sinter earlier causing voids to be trapped inside the preforms.

This can also result in non-uniform mechanical properties.

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