Variable vane having body formed of first material and trunnion formed of second material

1. A variable vane comprising:

a variable vane body including an airfoil portion, the variable vane body being formed of a first material; and

a trunnion attached at one end of the variable vane body, the trunnion including a pivot formed of a second, different material, wherein the first material has a first density and the second material has a second density that is greater than the first density.

2. A variable vane comprising:

a variable vane body including an airfoil portion, the variable vane body being formed of a first material; and

a trunnion attached at one end of the variable vane body, the trunnion including a pivot formed a second, different material, wherein the variable vane body includes a first anti-rotation member and the trunnion includes a second anti-rotation member that interlocks with the first anti-rotation member such that relative rotational movement between the trunnion and the variable vane body is limited.

3. The variable vane as recited in claim 2 , wherein the first material is selected from the group consisting of aluminum, aluminum-based alloys, magnesium, magnesium-based alloys, polymers, polymer-matrix composites and combinations thereof, and the second material is selected from the group consisting of nickel, nickel-based alloys, titanium, titanium-based alloys, steel, cobalt, cobalt-based alloys and combinations thereof.

4. The variable vane as recited in claim 2 , wherein the first material is an aluminum-based material and the second material is selected from the group consisting of nickel, nickel-based alloys, titanium, titanium-based alloys, steel, cobalt, cobalt-based alloys and combinations thereof.

5. The variable vane as recited in claim 2 , wherein the first material is a polymer-matrix composite and a second material is selected from the group consisting of nickel, nickel-based alloys, titanium, titanium-based alloys, steel, cobalt, cobalt-based alloys and combinations thereof.

6. The variable vane as recited in claim 2 , wherein the trunnion includes a flange connected to the pivot, and the flange is adhesively bonded to the variable vane body.

7. The variable vane as recited in claim 2 , wherein the first material has a first strength and a second material has a second strength that is greater than first strength.

8. The variable vane as recited in claim 2 , wherein one of the first anti-rotation member or the second anti-rotation member includes an elongated ridge and the other of the first anti-rotation member or the second anti-rotation member includes a channel.

9. A variable vane comprising:

a variable vane body including an airfoil portion, the variable vane body being formed of a first material; and

a trunnion attached at one end of the variable vane body, the trunnion including a pivot formed of a second, diiferent material, wherein the variable vane body includes a first alignment member and the trunnion includes a second alignment member inter-fit with the first alignment member such that a central axis of the variable vane body aligns with a central axis of the pivot.

10. The variable vane as recited in claim 9 , wherein one of the first alignment member or the second alignment member is a pin and the other of the first alignment member or the second alignment member is a hole.

11. The variable vane as recited in claim 2 , wherein the pivot includes a plurality of flat bearing surfaces.

12. The variable vane as recited in claim 2 , wherein the trunnion is adhesively bonded to the variable vane body.

13. The variable vane as recited in claim 2 , wherein the trunnion is welded or brazed to the variable vane body.

14. A turbomachine comprising:

optionally, a fan;

a compressor section including a plurality of variable vanes, each of the plurality of variable vanes including a variable vane body having an airfoil portion, and a trunnion attached at one end of the variable vane body, the variable vane body being formed of a first material and the trunnion including a pivot formed of a second, different material, wherein the variable vane body includes a first anti-rotation member and the trunnion includes a second anti-rotation member that interlocks with first anti-rotation member such that relative rotational movement between the trunnion and the variable vane body is limited;

a combustor in fluid communication with the compressor section; and

a turbine section in fluid communication with the combustor.

15. The turbomachine as recited in claim 14 , wherein the first material has a first density and the second material has a second density that is greater than the first density.

16. The turbomachine as recited in claim 14 , wherein the first material is selected from the group consisting of aluminum, aluminum-based alloys, magnesium, magnesium-based alloys, polymers, polymer-matrix composites and combinations thereof, and a second material selected from the group consisting of nickel, nickel-based alloys, titanium, titanium-based alloys, steel, cobalt, cobalt-based alloys and combinations thereof.

17. A method of assembling a variable vane, the method comprising:

providing a variable vane body including an airfoil portion, the variable vane body being formed of a first material and including a first anti-rotation member;

providing a trunnion including a pivot formed of a second, different material and including a second anti-rotation member; and

attaching the trunnion at one end of the variable vane body by interlocking the first anti-rotation member and the second anti-rotation member such that relative rotational movement between the trunnion and the variable vane body is limited.

18. The method as recited in claim 17 , wherein the attaching includes adhesively bonding, welding or brazing the trunnion to the one end of the variable vane body.