Heat treatment devices and method of operation thereof to produce dual microstructure superalloy disks

A method for differentially heat treating a superalloy disk having a gamma prime solvus temperature to obtain a dual microstructure disk, said disk comprising an inner section termed the bore portion with a bore hole, an intermediate section termed the web portion, an outer section termed the rim portion, and first and second faces on opposite sides of the said disk, said disk having predetermined diameter and thickness dimensions for said rim and bore portions,

• providing first and second thermal blocks respectively arranged on said first and second faces of said disk, each of said first and second thermal blocks having predetermined diameter and thickness dimensions related to said predetermined diameter and thickness dimensions of said disk by a predetermined relationship, said diameter of said first and second thermal blocks being less than said diameter of said disk, said first and second thermal blocks each has upper and lower faces with the lower face of the first thermal block having an alignment pin positionable in correspondence with said bore hole of said disk and the upper face of the second thermal block having an alignment pin positionable in correspondence with said bore hole of said disk;
• providing first and second alignment plates each with a diameter greater than the diameter of said first and second thermal blocks and with a periphery and having means for being respectively fastened to the upper face of the first thermal block and to the lower face of the second thermal block;
• providing first and second outer shells respectively located outside of the periphery of said first and second alignment plates with high temperature insulating media filling the cavity between the outer shells and thermal blocks;
• positioning each of said alignment pins of said first and second thermal blocks in correspondence with said bore hole of said disk;
• bringing together said first and second thermal blocks, first and second alignment plates, the first and second shells with the associated high temperature insulating media, and said disk and exposing said rim portion;
• selectively attaching a thermocouple to either said first or second thermal block;
• placing the brought together disk, the first and second thermal blocks, first and second alignment plates, first and second shells with the associated high temperature insulating media, and the thermocouple in a furnace;
• heat treating the disk in a furnace at a temperature which is above said gamma prime solvus temperature of said disk for a first predetermined duration;
• removing the disk and heat treatment assembly from furnace when thermocouple reaches the subsolvus temperature of said disk alloy;
• freeing said disk from heat treatment assembly;
• and
• quenching said disk.