Patent ID: 7311500

Claim:
A turbomachine blade comprising a root portion and an aerofoil portion, the aerofoil portion having a leading edge, a trailing edge, a concave metal wall portion extending from the leading edge to the trailing edge and a convex metal wall portion extending from the leading edge to the trailing edge, the concave metal wall portion and the convex metal wall portion forming a continuous integral metal wall, the aerofoil portion having a hollow interior defined by at least one internal surface, the hollow interior of the aerofoil portion being at least partially filled with a vibration damping material, the vibration damping material being bonded to the at least one internal surface and wherein a vibration damping and stiffening system comprises a variation of material properties between the wall portions wherein the vibration damping and stiffening system comprises a damping layer and a stiffening core, the damping layer is disposed on the internal surface and the stiffening core is disposed within the damping layer wherein a second damping layer comprises a modulus between that of a first damping layer and that of the stiffening core.