Method for manufacturing a dual alloy cooled turbine wheel

A method of manufacturing a cooled dual alloy turbine wheel having a hub portion and a plurality of thin blades projecting radially outwardly from said hub portion, said method comprising the steps of:

• (a) producing a hollow cylinder of first superalloy material having high creep rupture strength, said hollow cylinder having an axial hole therein;
• (b) filling said hole with second superalloy material having the properties of high tensile strength and high low-cycle-fatigue strength and permanently bonding said second superalloy material to said first superalloy material;
• (c) slicing said cylinder into a plurality of relatively thin, precisely flat wafers;
• (d) forming a plurality of cooling holes in each of said wafers at predetermined locations thereof;
• (e) aligning and stacking said wafers and bonding said wafers into a laminated dual alloy cylinder with fluid cooling passages extending through blade locations in said laminated dual alloy cylinder whereat said thin blades are to be subsequently formed;
• and
• (f) machining said laminated dual alloy cylinder to produce said thin blades, said fluid cooling passages extending through various ones of said blades, respectively, to form said cooled dual alloy turbine wheel with blades having high creep rupture strength and with said hub having high low-cycle-fatigue and tensile strengths.

A method of manufacturing a cooled turbine wheel having a hub portion from which a plurality of blades outwardly extend, said method comprising the steps of:

• (a) providing a plurality of thin metallic laminae each having a central portion with a high tensile strength and a high low cycle fatigue strength and a contiguous peripheral portion having high creep rupture strength by forming the central portion and the peripheral portion during separate steps and then diffusion bonding an outer edge of the central portion to an inner edge of the peripheral portion;
• (b) forming holes through said laminae;
• (c) intersecuring said laminae in a stacked relationship in which said holes are relatively oriented to define at least one cooling passage extending through the stacked laminae;
• and
• (d) removing part of the said peripheral portions of said laminae to define, in the stacked laminae, said blades.

A method of manufacturing a cooled turbine wheel having a hub portion from which a plurality of blades outwardly extend, said method comprising the steps of:

• (a) providing a central metallic hub portion having high tensile strength and high low-cycle-fatigue strength;
• (b) providing a plurality of thin, annular metallic laminae each having high creep rupture strength;
• (c) forming holes through said laminae;
• (d) intersecuring said laminae in a stacked relationship in which said holes are relatively oriented to define at least one cooling passage extending through the stacked laminae;
• (e) securing the inner edges of said laminae to said central metallic hub portion;
• and
• (f) removing part of said peripheral portions of said laminae to define, in the stacked laminae, said blades.