Method of manufacturing a blade

• US 8,555,501 B2
• Filed: 02/03/2010
• Issued: 10/15/2013
• Est. Priority Date: 02/27/2009
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Brennand, Phillip
• Primary Examiner(s): Omgba, Essama
• Assistant Examiner(s): Walters, Ryan J
• Application Number:
  US12/699,547
• Publication Number:
  US 20100281690A1
• Time in Patent Office: 1,350 Days
• Field of Search: 298/897, 298/897.2, 294/211, 228/157, 228/190, 244/123.14
• US Class Current: 29/889.72
• CPC Class Codes: B21D 26/055 Blanks having super-plastic properties
• CPC Class Codes: B21D 53/78 propeller blades; turbine blades
• CPC Class Codes: B23K 20/023 Thermo-compression bonding
• CPC Class Codes: B23K 20/18 Zonal welding by interposing weld-preventing substances between zones not to be welded
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23P 15/04 turbine or like blades from several pieces
• CPC Class Codes: F01D 5/147 Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F05D 2230/236 Diffusion bonding
• CPC Class Codes: F05D 2230/31 Layer deposition
• CPC Class Codes: F05D 2250/18 patterned
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10T 29/49336 Blade making
• CPC Class Codes: Y10T 29/49339 Hollow blade

Abstract

A method of manufacturing a blade comprising: applying a stop-off material in a first predetermined pattern between a first layer and a membrane so as to prevent a diffusion bond from forming between the first layer and the membrane across said first predetermined pattern; and applying the stop-off material in a second predetermined pattern between a second layer and the membrane; wherein the first and second predetermined patterns are arranged to allow a diffusion bond to be formed along the blade tip edge, the diffusion bond along the blade tip edge extending across the blade in a chord-wise direction; applying the first and second predetermined patterns so that over at least a first portion of the blade chord at the blade tip, a greater portion of the first layer at the tip edge, extending in a span-wise direction, is diffusion bonded to the membrane than the opposing second layer.

Claims

1. A method of manufacturing a blade for a turbomachine by superplastic forming and diffusion bonding a first layer, a second layer and a membrane, the membrane being disposed between the first and second layers, the method comprising:

applying a stop-off material in a first predetermined pattern between the first layer and the membrane so as to prevent a diffusion bond from forming between the first layer and the membrane across said first predetermined pattern; and

applying additional stop-off material in a second predetermined pattern between the second layer and the membrane so as to prevent a diffusion bond from forming between the second layer and the membrane across said second predetermined pattern;

wherein

the first and second predetermined patterns are arranged so as to allow a diffusion bond to be formed along the blade tip edge, the diffusion bond along the blade tip edge extending across the blade in a chord-wise direction;

the first and second predetermined patterns are applied so that over at least a first portion of the blade chord at the blade tip, a greater portion of the first layer at the tip edge, extending in a span-wise direction, is diffusion bonded to the membrane than the opposing second layer;

the second pattern is applied such that it defines one or more strips arranged in a span-wise direction, the strips being void of the additional stop-off material;

the second pattern is applied such that it defines one or more dots, the dots being void of the stop-off material; and

the second pattern is applied such that one of the one or more dots are located between one of the one or more strips and the blade tip edge.

2. The method of manufacture according to claim 1, wherein the first pattern is applied such that it defines one or more strips arranged in a span-wise direction, the strips being void of the stop-off material.

3. The method of manufacture according to claim 1, wherein the first layer forms a pressure surface or a suction surface of the turbomachine blade and the second layer forms the other of the pressure surface or suction surface.

4. The method of manufacture according to claim 1, wherein the blade is a compressor fan blade.

5. The method of manufacture according to claim 1, wherein the method further comprises applying the first and second predetermined patterns so that over at least a second portion of the blade chord at the blade tip, a greater portion of the second layer at the tip edge extending in a span-wise direction is diffusion bonded to the membrane than the opposing first layer.

6. The method of manufacture according to claim 1, wherein the method further comprises heating and pressing the first and second layers and the membrane to diffusion bond the first and second layers and the membrane together to form an integral structure.

7. The method of manufacture according to claim 1, wherein the method further comprises placing the first and second layers and the membrane between appropriately shaped dies;

heating the first and second layers, the membrane and dies; and

supplying a pressurized fluid between the first and second layers to cause at least one of the first and second layers to be superplastically formed.