Industrial Materials Technology, Inc.

Daniel H Zick

Robert Widmer

Jane L LaGoy

A new class of ductile iron is formed by the hot isostatic pressing of a ductile iron casting, followed by austempering of the ductile iron casting. Hot isostatic pressing can be carried out at a pressure in the range of 10,000 to 17,000 psi at a temperature above 1600.degree. F., and usually in the range of 1850.degree. F. to 2050.degree. F. Austempering of the material is carried out by heating to the austenitizing temperature (about 1500.degree. F. to 1800.degree. F.), maintaining the austenitizing temperature for a suitable time period, and rapidly cooling to an austempering temperature (about 400.degree. F. to 750.degree. F.) to form ausferrite within the sample.

Class of ductile iron, and process of forming same

The invention includes an apparatus and method for hot isostatic compaction of compactible material in a heated and pressurized environment within a pressure vessel, having a compaction container which can be hermetically sealed over a load, and which can transmit pressure from the pressure vessel to the load sealed in the container, a compaction die which can be hermetically sealed within the container, the die having an interior wall area which defines within the die an internal cavity having a width measured along a first axis, the die interior wall area extending along a second axis transverse to the first axis to generally define the height of the die cavity, the die having a wall thickness measured along the first axis, and a punch arrangement for applying compacting force to the compactible material and having a width essentially equal to the die cavity width such that when the punch arrangement is loaded oriented along the first axis within the die cavity, respective ends of the punch arrangement contact the die interior wall area, the die wall thickness being selected according to the separation between portions of the punch arrangement, such that pressure on the container will force the punch arrangement to travel along the second axis to compact the loaded compactible material charge along the second axis.

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Andover, MA, United States of America

Daniel H Zick