초록 ▼

Embodiments of the invention relate to a robust turbine vane made of stacked airfoil-shaped CMC laminates. Each laminate has an in-plane direction and a through thickness direction substantially normal to the in-plane direction. The laminates have anisotropic strength characteristics in which the in

Embodiments of the invention relate to a robust turbine vane made of stacked airfoil-shaped CMC laminates. Each laminate has an in-plane direction and a through thickness direction substantially normal to the in-plane direction. The laminates have anisotropic strength characteristics in which the in-plane tensile strength is substantially greater than the through thickness tensile strength. Thus, the laminates can provide strength in the direction of high thermal gradients and, thus, withstand the associated high thermal stresses. The laminates are relatively weak in through thickness (interlaminar) tension, but, in operation, relatively low through thickness tensile stresses can be expected. The laminates can be strong in through thickness compression; accordingly, the laminate stack can be held in through thickness compression by one or more fasteners. The CMC material can permit the inclusion of additional features such as cooling passages, ribs, spars, and thermal coatings, without compromising the strength characteristics of the material.

대표청구항 ▼

What is claimed is: 1. A ceramic matrix composite laminate comprising: a laminate having an airfoil-shaped outer peripheral surface, the laminate having an in-plane direction and a through thickness direction, the through thickness direction being substantially normal to the in-plane direction, the

What is claimed is: 1. A ceramic matrix composite laminate comprising: a laminate having an airfoil-shaped outer peripheral surface, the laminate having an in-plane direction and a through thickness direction, the through thickness direction being substantially normal to the in-plane direction, the laminate being made of an anisotropic ceramic matrix composite (CMC) material, wherein the in-plane tensile strength of the laminate is substantially greater than the through thickness tensile strength of the laminate. 2. The laminate of claim 1 wherein the in-plane tensile strength is at least three times greater than the through thickness tensile strength. 3. The laminate of claim 1 wherein the CMC material includes a ceramic matrix and a plurality of fibers therein, wherein substantially all of the fibers are oriented substantially in the in-plane direction of the laminate. 4. The laminate of claim 3 wherein a first portion of fibers extend in a first in-plane direction and a second portion of fibers extend in a second in-plane direction, wherein the first and second in-plane directions are oriented at about 90 degrees relative to each other. 5. The laminate of claim 1 wherein the laminate includes through thickness cutouts so as to form one of a rib or a spar in the laminate. 6. The laminate of claim 1 wherein the laminate includes at least one of recesses, serrations and cutouts about at least a portion of the outer peripheral surface. 7. A turbine vane assembly comprising: a plurality of airfoil-shaped laminates radially stacked so as to define a turbine vane, the vane having an outer peripheral surface and a planar direction and a radial direction, the radial direction being substantially normal to the planar direction, wherein each laminate is made of an anisotropic ceramic matrix composite (CMC) material such that the planar tensile strength of the vane is substantially greater than the radial tensile strength of the vane. 8. The vane assembly of claim 7 wherein the planar tensile strength is at least three times greater than the radial tensile strength. 9. The vane assembly of claim 7 wherein the CMC material includes a ceramic matrix and a plurality of fibers therein, wherein substantially all of the fibers are oriented substantially in the planar direction of the vane. 10. The vane assembly of claim 9 wherein the fibers are arranged in two planar directions in the vane, a first portion of the fibers extend in a first planar direction and a second portion of the fibers extend in a second planar direction, wherein the first and second planar directions are oriented at about 90 degrees relative to each other. 11. The vane assembly of claim 9 wherein at least one pair of adjacent laminates have a uni-directional fiber arrangement, the pair of laminates including a first laminate and a second laminate, substantially all of the fibers in the first laminate extend in a first planar direction, substantially all of the fibers in the second laminate extend in a second planar direction, and wherein the first and second planar directions are oriented at about 90 degrees relative to each other. 12. The vane assembly of claim 7 further including a fastening system including an elongated fastener and a retainer, the fastener extending radially through a radial opening provided in the vane, wherein at least one end of the fastener is closed by the retainer so as to hold the plurality of laminates in radial compression. 13. The vane assembly of claim 7 further including a stiffened fastening system including at least two tie rods extending radially through at least one opening provided in the vane, the tie rods being joined so as to form a single rigid fastener, wherein the ends of the tie rods are closed by retainers so as to hold the plurality of laminates in radial compression, whereby the stiffened fastener system can reduce the possibility of radial creep of the fasteners and laminates. 14. The vane assembly of claim 7 wherein the plurality of laminates includes alternating large laminates and small laminates so as to form a vane having a stepped outer peripheral surface. 15. The vane assembly of claim 7 wherein at least one of the laminates is staggered from the other laminates so as to form a vane with an irregular outer peripheral surface. 16. The vane assembly of claim 7 wherein each of the laminates in the stack has an outer peripheral edge, wherein at least two of the laminates have a tapered outer peripheral edge. 17. The vane assembly of claim 7 wherein the laminates form an irregular outer peripheral surface of the vane. 18. The vane assembly of claim 17 further including a thermal insulating material applied over the outer peripheral surface of the vane. 19. The vane assembly of claim 7 wherein at least one pair of adjacent laminates are joined by at least one of co-processing, sintering and bonding material applied between the laminate pair. 20. The vane assembly of claim 7 further including a coolant supply opening extending radially in the vane, wherein each of the laminates have a leading edge and a trailing edge, wherein at least one of the laminates includes a channel extending from the trailing edge and into fluid communication with the coolant supply opening, whereby a coolant can be provided to the trailing edge of the vane assembly.