12 TH INTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING

1. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING Development of Constructive and Technological Solutions for the Manufacture of Blisks Turbine by Connecting the Disk with Shrouded Blades under Hot Isostatic Pressing Dr. Liubov Magerramova1, Dr. Eugene Kratt2 1Central Institute of Aviation Motors (CIAM), Moscow, Russia, lamagerramova@mail.ru 2Laboratory New Technology (LNT), Moscow, Russia, kratt@rambler.ru

2. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING INTRODUCTION • The constantly evolving characteristic requirements of gas turbine engines have led to an overall increase in thermal loading on engine parts. • The wheel elements of gas turbines operate under conditions of non-uniform loading and heating along the radius. • Consequently, the materials for the different parts of the wheel must meet different requirements. Therefore, the resulting structure must have the most appropriate materials placed in areas that best suit the given working conditions. • One region recognized as a stress concentrator is the lock connection of the blades with the disk. The stress at this location limits the life of the wheel and reinforcement results in a greater disk weight. • Wheels with detachable blades often do not allow placement of the necessary (in term of gas-dynamic efficiency) number of blades. The temperature field The design of the wheel may take the form of a bimetallic blisk, where the blades and the disk part are made of different materials

3. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING THE REQUIREMENTS TO THE TURBINE WHEEL OF A GAS TURBINE ENGINE • The mass reduction of the wheel, • The increasing the efficiency of the turbine wheel, • The air mass flow for cooling would not exceed that in the original design, • The ensuring both reliable contact on the shroud working faces during actual operation regime, • design of the joint zone based on stress-strain state and strength calculations at operated conditions taking into consideration mechanical properties of the materials; • The consideration of strength and detuningrequirements , • possibility of damping blade oscillations; • possibility of cooling at the rim for disk and blades; • The possibility of production. The absence of blade - disk lock joints allows to prevent leakages, to solve a problem of the blade location on the disk, i.e. to provide the turbine lattice density required for high gas dynamic parameters that can result in the engine efficiency increasing. The bimetallic blisk design consisted of shrouded blades made of a heat resistant superalloy and a disk part made of a nickel alloy powder. An advanced technological process is proposed to produce blisks

4. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING PROJECT DEVELOPMENT OF A BLISK WITH SHROUDED BLADES • The configuration of the shroud is selected by minimization of mass with following requirements: • The number of blades for the blisks is the same as for the prototype. • Gas leakage should be prevented from the suction side of the blade in trailing edge area; • Radial clearances over the shroud fins should not exceed 0.2 mm under operating conditions. This can be done by installation of appropriate inserts above the rotor; • The gaps between the contact faces of the shrouds during assembly of the blades should be sufficient to prevent their connection in the HIP process; • The contact of shrouds in the working conditions should occur when the speed rotation is not less than 50%; • The strength of the shrouds and blade zones under the shrouds should be sufficient. The design of the shroud The shrouds come into contact when the rotation speed is about 25%. With increasing rotation speed, the contact pressure and contact area increase.

5. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING CONNECTION ZONE The location and configuration of the connection zone of the blade with the disc part are determined by the demand of minimization of weight of wheels and satisfaction of the requirements of strength under specified conditions of operation and capabilities of the production process. Min M,MplMax M,Mpl The von Mises plastic strain MinKm (blisk) > MinKm (prototype) by 10-24% Min MMax M The weight of the designed blisks was reduced in comparison with the mass of the prototype by 5–15%. The von Mises stress

6. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING TECHNOLOGICAL ASPECTS The process of joining components at high temperature and pressure by the HIP method is accompanied by a shrinkage of the powder disc alloy in the gap between the disc part and the blades (db). Allowing movement of the blades to the disk in the process of shrinkage of the powder requires the assembly of the blades in the capsule in a special fixture that makes gaps between the shrouds (initial sh) The initial sh ? to HIP after =0 This gap is necessary to: -reliable filling of the powder material; -resistant seal powder. The initial gap between the central disk and the annular assembly of the blades and embedded items is chosen as 5 mm Capsule for forming a bimetallic blisk: 1-capsule, 2-embedded elements, 3-central part, 4-fixing elements, 5-cast blades The bimetallic blisk consisting of single-crystal blades with shrouds and a disk consisting of a granulated heat-resistant nickel base alloy, connected by hot isostatic pressing

7. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING INDIVIDUAL ITEMS CAPSULAR SNAP Assembly diagram Embedded elements Cast blades Cast blades and fittings Assembly

8. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING SIMULATION RESULTS CAPSULAR SHRINKAGE The contour of the capsule before HIP The contour after HIP The scheme of assembly The results of the simulation of the shrinkage of the capsules blisks at HIP before HIP after HIP

9. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING THE TECHNOLOGICAL PROCESS OF MANUFACTURING OF BLISKS WITH SHROUDED BLADES OF THE ALLOYS ZHS32 OR ZHS6U AND DISC FROM JEP741NP • Cast of the blades (ZHS32) • Manufacturing of capsules for the Central part of the disk • Manufacturing of Central disc part blisks by HIP (JEP741NP) separately to minimize shrinkage at the final shaping of blisks • Manufacture of capsule snap to connect the disc part and blades • Manufacturing of embedded elements • The Assembly in the capsule tooling with blades and the disс part. • Conduct of the HIP: a pressure of 15,000 ATM. 1200°C, 2.5 hours • Homogenization of blisks at 1200°C, 4 hours (for ZHS6U and JEP741NP), Aging (910°C - 3h, 750°C – 8 hours. 700°C – 12 HR.) • Removal of the capsule and embedded elements, machining

10. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING DEVELOPING AN EFFECTIVE METHOD OF CAPSULE PRODUCTION EQUIPMENT FOR PRODUCTION OF BILLETS BLISKS WITH THE ASSISTANCE OF MODERN TECHNOLOGY For the manufacture of the elements of the capsule mounting rings and the filling pipes, it is advisable to use a machining of sheet materials For manufacturing of the embedded elements on the stage of working out the geometry of the blisks (1 and 2 iterations) the most appropriate use of additive technologies. Element capsule is made by lathe Welding of individual elements of the capsule is recommended using argon-arc welding

11. HIP ’17 12THINTERNATIONAL CONFERENCE ON HOT ISOSTATIC PRESSING SUMMARY • As a result of this work were developed: • A turbine wheel design without a locking connection of the blades with the disk is proposed. • Gas turbine shrouded blades were designed based on the turbine wheel with a lock connection between the disk and the uncooled blades. • The gas flow calculations in the turbine flow path of designs showed an increase in turbine efficiency of almost 2%for the modified wheel. • The blisk is proposed to made of two Ni-based materials(superalloy for the blades and powder alloy for the disk).The weight is 7% lower for the blisk than for the prototype. • The location and configuration of the connection zone of the blades with the disk part of the blisk were determined from the conditions that minimized the mass of the wheels but still maintained the strength requirements and capabilities of the process. • The technological process of manufacturing bimetallic blisks with shrouded blades by hot isostatic pressing method was suggested. • The capsule for forming central part of disk and assembling disk and blades was developed. • Calculation of shape changing of capsule during hot isostatic pressing process was carried out. • The elements of tooling and technological process were designed.

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