Open-cell reticulated foam

• US 10,035,174 B2
• Filed: 02/09/2015
• Issued: 07/31/2018
• Est. Priority Date: 02/09/2015
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Noraas, Ryan B., Bullied, Steven J.
• Primary Examiner(s): Kerns, Kevin P
• Assistant Examiner(s): Ha, Steven S
• Application Number:
  US14/617,291
• Publication Number:
  US 20160228913A1
• Time in Patent Office: 1,268 Days
• CPC Class Codes: B05D 1/24 Applying particulate materials
• CPC Class Codes: B05D 3/007 After-treatment
• CPC Class Codes: B22C 7/023 Patterns made from expanded plastic materials
• CPC Class Codes: B22C 9/046 Use of patterns which are eliminated by the liquid metal in the mould
• CPC Class Codes: C08J 9/36 After-treatment C08J9/22 takes precedence
• CPC Class Codes: F01D 5/28 Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
• CPC Class Codes: F01D 5/288 Protective coatings for blades
• CPC Class Codes: F04D 29/324 Blades
• CPC Class Codes: F05D 2220/36 specially adapted for the fan of turbofan engines
• CPC Class Codes: F05D 2230/31 Layer deposition
• CPC Class Codes: F05D 2240/303 related to the leading edge of a rotor blade
• CPC Class Codes: F05D 2300/43 Synthetic polymers, e.g. plastics; Rubber
• CPC Class Codes: F05D 2300/603 Composites; e.g. fibre-reinforced
• CPC Class Codes: F05D 2300/612 Foam
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A foam for use in a lost-foam casting process utilized in the manufacture of a component for a gas turbine engine, the foam having a void fraction less than or equal to ninety five percent, is disclosed. The foam may include a first layer comprising polymer foam having an open-cell structure and a void fraction greater than ninety five percent. A second layer, comprising adhesive, may be adhered to the first layer. A third layer comprising particulate material may be adhered to the second layer.

Claims

1. A method of manufacturing a fan blade for a gas turbine engine, comprising:

providing a polymer foam having an open-cell structure and a void fraction greater than ninety five percent;

coating the polymer foam with an adhesive to create an adhesive coated foam;

applying a particulate material to the adhesive coated foam to make a modified foam having a void fraction less than or equal to ninety five percent;

covering the modified foam having a void fraction less than or equal to ninety five percent with a refractory material;

curing the refractory material until it hardens to form an investment;

heating the investment to a temperature above the boiling point of the modified foam having a void fraction less than or equal to ninety five percent to form a negative of the modified foam;

adding molten metal or metal alloy to the negative, followed by cooling the negative to a temperature below the melting temperature of the metal or metal alloy to form a positive of the modified foam;

removing the refractory material to form an open-cell metal foam having a void fraction less than or equal to ninety five percent; and

enveloping the open-cell metal foam having a void fraction less than or equal to ninety five percent with an outer shell of a first material, the outer shell having the shape of an airfoil, to form a fan blade for a gas turbine engine.

2. The modified foam according to claim 1, wherein the polymer foam is one of polyurethane polymer foam, polyvinyl chloride polymer foam, polystyrene polymer foam, polyimide polymer foam, silicone polymer foam, polyethylene polymer foam, polyester polymer foam, polypropylene foam and combinations thereof.

3. The foam according to claim 1, wherein the adhesive is an adhesive polymer one of acrylic polymer, alkyd polymer, styrene acrylic polymer, styrene butadiene polymer, vinyl acetate polymer, vinyl acetate homopolymer polymer, vinyl acrylic polymer, vinyl maleate polymer, vinyl versatate polymer, vinyl alcohol polymer, polyvinyl chloride polymer, polyvinylpyrrolidone polymer, casein and combinations thereof.

4. The foam according to claim 1, wherein the particulate material is one of wax powder, wood flour, polymer powder and combinations thereof.

5. The foam according to claim 4, wherein the wax powder is one of animal wax powder, vegetable wax powder, mineral wax powder, petroleum wax powder and combinations thereof.

6. The foam according to claim 4, wherein the polymer powder is one of polyurethane polymer powder, polyvinyl chloride polymer powder, polystyrene polymer powder, polyimide polymer powder, polyethylene polymer powder, polyester polymer powder, polypropylene polymer powder and combinations thereof.

7. The method of manufacturing the foam according to claim 1, wherein the coating the polymer foam with an adhesive step comprises applying an emulsion to the polymer foam, the emulsion comprising an adhesive polymer and solvent.

8. The method of manufacturing the foam according to claim 7, further comprising removing excess solvent from the polymer foam before applying a particulate material to the adhesive.

9. The method of manufacturing the foam according to claim 1, wherein the applying a particulate material to the adhesive includes passing the adhesive coated polymer foam through a fluidized bed of particulate material.

10. The method for manufacturing the fan blade according to claim 1, wherein the polymer foam is polyurethane polymer foam, the adhesive is vinyl acetate, the particulate material is polyethylene polymer powder and the metal or metal alloy is aluminum.

11. The method for manufacturing the fan blade according to claim 1, wherein the outer shell of a first material is made of a metal or metal alloy selected from the group comprising;

aluminum, titanium and nickel, aluminum alloys, steel, nickel alloys and titanium alloys.

12. The method of manufacturing the fan blade according to claim 1, wherein the outer shell of a first material is made of a composite material, and the composite material is made of fiber embedded in resin.