Method and apparatus for hot forming of sheet metal in titanium-base alloys
AssigneeRolls-Royce Deutschland Ltd & Co KG
InventorKarl Schreiber
Life of this patent
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Abstract
A titanium sheet to be formed is heated in a sealingly closed tool by the radiation heat from the heating elements integrated into the tool to a forming temperature not exceeding 600° C., and is deformed towards a cold tool contour by the action of a non-oxidizing gaseous pressure medium introduced into the tool and heated to the hot-forming temperature, as well as by underpressure generated on the side of the workpiece facing away from the pressure medium.
Claims19
A method for hot forming of sheet metal of titanium-base alloys in a forming apparatus, comprising:
- holding a sheet of titanium-base alloy to be formed between two sealingly closed halves of a tool, thereby forming a pressure side of the tool and a vacuum side of the tool on opposite sides of the held sheet,
- heating the sheet from the pressure side to a hot-forming temperature with radiation heat from heating elements integrated into the tool, and
- deforming the sheet towards a vacuum side tool contour by action of a heated gaseous pressure medium free from oxidizing constituents injected into the pressure side and the further action of a vacuum generated on the vacuum side of the titanium-base alloy sheet facing away from the pressure medium;
- maintaining the vacuum side tool contour cold relative to the heated sheet of titanium-base alloy during the deforming of the sheet such that the heated sheet of titanium-base alloy is immediately cooled and stabilized upon contact of the sheet with the cold vacuum side tool contour.
A forming apparatus for hot forming of sheet metal of titanium-base alloys, comprising:
- a forming tool having a first portion having a forming tool contour and second portion having a hollow body, between which first portion and second portion a sheet of titanium-base alloy to be formed can be sealingly held,
- at least one heating element positioned in the hollow body directed towards the sheet for heating the sheet,
- an inlet port in the tool for supplying a gaseous pressure medium to one side of the sheet, and
- an evacuation port in the tool for generating a vacuum on an opposite side of the sheet;
- wherein the second portion of the forming tool is not directly heated to maintain a cold forming tool contour relative to the heated sheet of titanium-base alloy for cooling and stabilizing the heated sheet of titanium-base alloy upon contact with the cold forming tool contour.
A forming apparatus for hot forming of sheet metal of titanium-base alloys, comprising:
- a forming tool having a forming tool contour and a hollow body between which a sheet of titanium-base alloy to be formed is sealingly held,
- at least one heating element positioned in the hollow body directed towards the sheet,
- an inlet port in the tool for supplying a gaseous pressure medium to one side of the sheet,
- an evacuation port in the tool for generating a vacuum on an opposite side of the sheet,
- a heat exchanger positioned outside of the forming apparatus for heating the pressure medium prior to entry into the forming tool.
A method for hot forming of sheet metal of titanium-base alloys in a forming apparatus, comprising:
- holding a sheet of titanium-base alloy to be formed between two sealingly closed halves of a tool,
- heating the sheet to a hot-forming temperature with radiation heat from heating elements integrated into the tool,
- deforming the sheet towards a cold tool contour by action of a heated gaseous pressure medium free from oxidizing constituents and the further action of a vacuum generated on a side of the titanium-base alloy sheet facing away from the pressure medium;
- heating the pressure medium in a heat exchanger outside of the forming apparatus.
Dependencies are inferred from the claim text.