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:
Jan. 06, 1976
Filed:
Jan. 27, 1975
Donald E Witkin, Warren, PA (US);
National Forge Company, Irvine, PA (US);
Abstract
Method for compacting preheated powder bodies in a high pressure isostatic pressure vessel in which a liquid such as water is used as the pressurizing medium. A preheated workpiece is inserted into the vessel which is closed and sealed. The vessel is then rapidly filled with the liquid pressurizing medium while avoiding contact of the medium with the preheated workpiece until the vessel is substantially completely full. The pressure within the vessel is then increased rapidly to a preselected compacting level by continually pumping the liquid pressurizing medium into the vessel. The preselected compacting pressure is in excess of the critical pressure of the liquid pressurizing medium. The rapid increase of pressure within the vessel to a level exceeding the critical pressure minimizes the amount of vapor that is formed in the vessel and reduces heat transfer from the preheated body to the pressurizing system. In a preferred embodiment, avoidance of contact of the pressurizing medium with the preheated workpiece until the vessel is substantially completely filled is accomplished by the use of a shielding container. Alternative means are disclosed. Means for increasing the temperature of the workpiece after it is inserted into the pressure vessel are disclosed. Means for rapidly reducing the pressure within the vessel and for withdrawing the pressurizing medium are also disclosed.