Controlled environment superplastic forming of metals
AssigneeRockwell International Corporation
InventorsCharles Howard Hamilton, Fred B. Koeller, Roger S. Raymond, Martin Goldberg
Life of this patent
Estimating the term…
Abstract
Metals such as titanium alloy blanks which are subject to contamination by air at elevated temperatures are precision formed into desired shapes in a controlled environment. The metal worksheet and a shaping member are located within an enclosure. An inert gas environment is provided in the enclosed area. The metal worksheet is heated to a suitable forming temperature and stretched substantially in excess of its original surface area under tensile stress from a fluid pressure loading and formed into the desired shape by interaction with the shaping member. Novel sealing arrangements for the enclosed area of the forming apparatus are provided.
Claims17
A method of making metallic forms in a controlled environment comprising:
- providing at least one shaping member having a surface formed complimentary to the shape desired to be formed;
- providing a metal blank having an effective strain rate sensitivity and two opposed principal surfaces;
- enclosing an area around said metal blank and said at least one shaping member, said enclosed area being divided into first and second chambers by said metal blank, said metal blank being positioned as a diaphram between said chambers, said at least one shaping member being located in said first chamber;
- providing an inert gas environment in said chambers;
- heating said metal blank to a temperature suitable for superplastic forming;
- and
- controlling the fluid pressure of said inert gas within said chambers to induce a pressure loading across the principal surfaces of said metal blank wherein the fluid pressure of said inert gas within said second chamber is greater than the fluid pressure of said inert gas within said first chamber, thereby causing said metal blank to deform into said first chamber and against, and into intimate contact with, said at least one shaping member.
Apparatus for making metallic forms from metal blank having an effective strain rate sensitivity in a controlled environment comprising:
- at least one shaping member having a surface formed complimentary to the shape desired to be formed;
- an enclosure around said metal blank and said at least one shaping member, said metal blank being positioned within said enclosure such that said enclosure is divided into first and second separate chambers, said at least one shaping member being located in said first chamber;
- means for heating said metal blank to a suitable forming temperature;
- and
- an environmental control means for providing an inert gas environment with said chambers during heating and forming of said metal blank and for regulating the inert gas pressure in said first and second chambers to induce a pressure loading across said metal blank to cause said metal blank to deform against, and into intimate contact with, said at least one shaping member.
Dependencies are inferred from the claim text.