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:
Sep. 28, 1982
Filed:
Feb. 25, 1981
Klaus Hunold, Kempten, DE;
Klaus Reinmuth, Durach, DE;
Alfred Lipp, Bad Worishofen, DE;
Johannes Napholcz, Kempten, DE;
Peter Arnold, Sulzberg, DE;
Elektroschmelzwerk kempten GmbH, Munich, DE;
Abstract
The invention is a process for the manufacture of substantially pore-free shaped articles from polycrystalline material, such as tungsten carbide, silicon nitride, titanium boride or silicon carbide, in which encased articles preformed from pulverulent materials and having open pores are isostatically hot-pressed in a vacuum-sealed casing of vitreous or ceramic-like material in a high-pressure autoclave using an inert gas as pressure-transfer medium. Before the application of the casing material, a first layer comprising material that can be decomposed or melted, such as an organic wax or a resin-like product, or of a compressible heat-resistant material such as inorganic fibers or felts, is applied to the preformed articles. Then, the encased articles are thermally treated until the glass or ceramic layer is fused or sintered gas-tight. The articles pretreated in this manner are then isostatically hot-pressed.