Filament reinforced gas turbine blade

Claim 2

A filament reinforced gas turbine engine blade having a divergent root portion having a particular splay radius comprising: high modulus, high strength, nonductile inner reinforcing filaments embedded in a matrix material and aligned in a spanwise direction in the blade portion and diverging outwardly in the portion, the smallest radius of curvature formed by said inner filaments in said root portion being greater than said splay radius but not smaller than its working radius; and high strength ductile outer reinforcing filaments embedded in a matrix material and aligned in a span-wise direction in the blade portion and diverging outwardly in the root portion, said outer filament-reinforced matrix material being bonded to said inner filament-reinforced matrix material, the smallest radius of curvature formed by said outer filaments being equal to said splay radius with essentially no loss of strength therein.

Claim 3

The blade of claim 1 wherein said inner reinforcing filaments are selected from the group consisting of boron, carbon, silicon carbide and silicon carbide coated boron.

Claim 4

The blade of claim 2 wherein said outer reinforcing filaments are selected from the group consisting of steel or titanium or alloys thereof.

Claim 5

A filament reinforced gas turbine engine blade having a splayed root being defined by a particular splay radius comprising: a plurality of substantially parallel elongated blade forming laminations disposed in a stack one on the other, one end of the stack having its laminations flaring centrally outwardly to form an enlarged inner root portion extending chordwise of the blade; said blade forming laminations including elongated sheets of high modulus, high strength, nonductile first reinforcing filaments embedded in a matrix material and aligned in a spanwise direction, the smallest radius of curvature formed by said blade forming laminations being greater than said splay radius but not smaller than the working radius of said first reinforcing filaments; a plurality of substantially parallel outer laminations disposed in a stack on each side of said blade forming laminations, the outer laminations covering said one end of the blade forming laminations and being flared outwardly to form the outer portion of said root; said outer laminations including sheets of ductile second reinforcing filaments embedded in a matrix material and aligned in a spanwise direction, said second reinfoRcing filaments being formed to a minimum radius of curvature which is equal to said splay radius with essentially no loss of strength; and a plurality of inserts disposed between said flaring blade-forming and outer laminations and bonded thereto to maintain the laminations in flaring relation.

Claim 6

A filament reinforced gas turbine engine blade having a splayed root being defined by a particular splay radius comprising: a plurality of substantially parallel elongated blade forming laminations disposed in a stack one on the other, one end of the stack having its laminations flaring centrally outwardly to form an enlarged inner root portion extending chordwise of the blade; said blade forming laminations including elongated sheets of high modulus, high strength, nonductile first reinforcing filaments embedded in a matrix material and aligned in a spanwise direction, the smallest radius of curvature formed by said blade forming laminations being greater than said splay radius but not smaller than the working radius of said first reinforcing filaments; a plurality of substantially parallel outer laminations disposed in a stack on each side of said blade forming laminations, the outer laminations covering said one end of the blade forming laminations and being flared outwardly to form the outer portion of said root; said outer laminations including sheets of ductile second reinforcing filaments embedded in a matrix material and aligned in a spanwise direction, said second reinfoRcing filaments being formed to a minimum radius of curvature which is equal to said splay radius with essentially no loss of strength; and a plurality of inserts disposed between said flaring blade-forming and outer laminations and bonded thereto to maintain the laminations in flaring relation.

Claim 7

The blade of claim 4 wherein said first reinforcing filaments are selected from the group consisting of boron, carbon, silicon carbide, and silicon carbide coated boron.

Claim 8

The blade of claim 5 wherein said second reinforcing filaments are steel or titanium or alloys thereof.