The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 19, 2002
Filed:
Jan. 26, 1999
Joseph M. Vihtelic, Whitehall, MI (US);
Philip D. Jackson, Muskegon, MI (US);
Jiri E. Kresta, Warren, MI (US);
Kurt C. Frisch, Grosse Ile, MI (US);
Howmet Research Corporation, Whitehall, MI (US);
Abstract
Method of making a shell mold for casting molten metals or alloys involves forming a thermally collapsible, low density reaction injection molded (RIM) thermosetting polyurethane foam pattern having a shape corresponding to the casting to be made. The pattern is formulated to have an aggregate density (pattern outer skin and pattern cellular core) in the range of about 10 to 15 lbs/ft and a smooth continuous as-molded surface devoid of surface connected open cells, dimensional stability over a range of temperatures, and ready, ashless burnout from the shell mold formed thereon without cracking the shell mold. The pattern is free of organometallic catalysts that should not be present in the casting of aerospace superalloys, such as nickel and cobalt base superalloys and titanium. The pattern then is invested without the need for any surface polymer or other film or layer in a shell mold.