Gas turbine engine rotor assembly

A method of manufacturing a rotor assembly for a gas turbine engine comprising the steps of:

• fabricating a metal disc having at least one axially extending annular flange at its radially outer periphery;
• fabricating a circumferential array of spaced aerofoil shaped metal blades, each blade comprising an aerofoil portion and a root portion which has at least one axially extending flange shaped complementary to at least part of the circumference of the at least one annular flange of the disc;
• mounting the array of blades on the radially outer periphery of the disc with the at least one flange of each blade confronting the at least one annular flange of the disc, the root portion of each blade and the disc each being provided with at least two spaced grooves that cooperate to define at least two spaced enclosed chambers at an interface between the disc and the root portion of each blade;
• sealing the interface between the disc and the root portion of each blade at a location adjacent a first of said chambers;
• and
• subsequently hot isostatically pressing the resultant assembly thereby to achieve diffusion bonding between the array of blades and the disc and between the at least one flange of each blade and the at least one annular flange of the disc, and to collapse a second of said chambers thereby to provide a visual indication of success of the diffusion bonding.

A method of manufacturing a rotor assembly for a gas turbine engine comprising the steps of:

• fabricating a member of circular cross-section;
• fabricating an array of aerofoil shaped blades, each blade comprising an aerofoil portion and a root portion;
• mounting each said blade on a radially outer peripheral portion of said member, the root portion of each said blade confronting said member, each said root portion and said member being provided with at least one pair of grooves that cooperate to define first and second enclosed chambers at an interface between said member and each said root portion;
• sealing the interface between each said root portion and said member at a location between the first chamber and a peripheral edge of each said root portion;
• and
• subsequently hot isostatically pressing the resultant assembly thereby to achieve diffusion bonding between each said blade and said member, and to collapse the second chamber thereby to provide a visual indication of success of the diffusion bonding.