US 5,729,901 AGranted

Method of manufacturing hollow articles by superplastic forming and diffusion bonding

AssigneeROLLS-ROYCE plc

InventorsJohn O. Fowler, Arnold J. S. Pratt

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Abstract

A plurality of hollow blades are produced by assembling a plurality of titanium sheets and a plurality of titanium blocks into a stack. At least one of the sheets is provided with a stop off material on one of its surfaces at a plurality of longitudinally spaced pre-selected areas to prevent diffusion bonding at these areas to define the hollow interiors of the blades. The edges and ends of the sheets are welded together and the blocks are welded to the sheets. The assembly is heated and externally pressurised to diffusion bond the sheets and blocks together. The integral structure so formed is then heated and internally pressurised to superplastically form at least one of the sheets at each of the pre-selected areas to produce a plurality of hollow blades. Thereafter the hollow blades are separated from each other by machining and simultaneously producing the aerofoil shapes.

Claims37

Dependent claims

A method of manufacturing hollow articles by superplastic forming and diffusion bonding at least two metal workpieces comprising the steps of

(a) defining a plurality of spaced preselected areas of at least one of the surfaces of at least one of the at least two metal workpieces to prevent diffusion bonding at the preselected areas, each preselected area corresponding to the hollow interior of one of a plurality of hollow articles,
(b) assembling the at least two workpieces into a stack,
(c) applying heat and pressure across the thickness of the at least two metal workpieces to diffusion bond the at least two workpieces together, in areas other than the plurality of spaced preselected areas to form an integral structure,
(d) heating and internally pressurising the preselected areas to cause the preselected areas to be superplastically formed to produce a plurality of hollow articles of predetermined shapes and a further step of parting the integral structure between the plurality of spaced preselected areas to provide a plurality of articles, said further step occurring between steps (c) and (d) or after step (d).

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 08/694,095Filed 8 Aug 1996
Granted: 24 Mar 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

B21D 26/055
Characterised by the material of the blanks: blanks having super-plastic properties
B21D 35/003
Processes combined with methods covered by groups B21D1/00 - B21D31/00: simultaneous forming, e.g. making more than one part per stroke
B21D 53/78
Making other particular articles: propeller blades; turbine blades
F01D 5/18
Form or construction: hollow blades, i.e. blades with cooling or heating channels or cavities ; Heating, heat-insulating or cooling means on blades