Gm Global Technolgoy Operations, Inc.

Hitchiner Manufacturing Co., Inc.

Metal Casting Technology, Incorporated

Qi Zhao

George D Chandley

Curtis A Harrison

A vaporizable refractory coated pattern assembly is formed having a sprue connected to a plurality of thin wall patterns of articles to be cast. The pattern assembly is supported in a refractory particulate media in an open bottom container that is evacuated to subambient pressure and rotated in a manner to distribute particulates to regions of the refractory coated patterns not yet directly contacted by particulates. The pattern assembly is comprised of relatively dense foam plastic pattern material that imparts increased strength to the thin wall patterns. The sprue includes a vent passage that communicates to a particulate media to vent pattern decomposition vapors thereto in a manner that enables faster replacement of the pattern assembly in the media, despite the use of the relatively dense pattern material.

Lost foam countergravity casting

Tooling for handling molten or hot solid aluminum and its alloys wherein the tooling is made of a passivated titanium aluminide (TiAl) intermetallic compound having a thin passivating surface oxide film formed in-situ thereon by contact with an oxygen-bearing atmosphere at elevated temperature. The surface oxide film passivates and renders the tooling non-wetted by and non-reactive with molten aluminum and its alloys and non-bonded to hot solid aluminum and its alloys.

Passivated titanium aluminide tooling

Fold defects are reduced or eliminated in lost foam castings by contacting a destructible polymeric pattern surface proximate to which deleterious fold defects comprising unbonded seams are prone to form in the solidifying molten metal with a material that reduces or eliminates fold defects in the casting proximate the pattern surface. The material can comprise a silicone layer that is anti-sticking relative to a gas permeable refractory layer on the pattern or foundry sand directly contacting the pattern surface depending on casting configuration. The pattern is cleaned prior to contact with the material. Lower melt casting temperatures can be used with concomitant improvements in casting microstructure (e.g. finer dendritic arm spacing) and mechanical properties.

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Nashua, NH, United States of America

Qi Zhao