Final Report Summary - DAFNE (Development of gamma-TiAl forgings in a low-cost near conventional hot-die process and process evaluation)
Executive Summary:
The strong need for higher efficiency, reduced CO2 emissions and weight reduction in aircraft engines leads to a demand of innovative light-weight high-temperature resistant materials which can partly substitute the materials currently employed. Presently, Ni-base alloys are used for turbine blades in aero-engines which satisfy the high mechanical and thermal requirements. A disadvantage of Ni-base alloys, however, is their high density of about 8 g/cm3. Intermetallic titanium aluminides, which exhibit a low density of about 4 g/cm3, are certainly among the most promising candidates to meet the required thermal and mechanical specifications. During the last decade several “wrought” gamma-TiAl alloys have been developed. These alloys exhibit excellent mechanical properties, but show a narrow processing window. Böhler Schmiedetechnik GmbH & Co KG is specialized on forging processes of materials like Ni-base and Ti-alloys for aero engine applications with a high demand on structure mechanical requirements. In cooperation with the Department of Physical Metallurgy and Materials Testing at the Montanuniversität Leoben as well as other project partners a novel Nb and Mo containing gamma-TiAl based alloy (TNM alloy) was developed. Due to optimized microstructure the alloy showed good malleability in first forging trials. An innovative approach of near conventional hot-die forging, which means that conventional forging equipment with minor and inexpensive modifications can be used, was made by Böhler Schmiedetechnik GmbH & Co KG. Aim of this project is to develop a robust low-cost near conventional hot-die forging process for low pressure turbine blades which meet on the one hand the requirements of the OEM and give the right direction for future serial production on the other hand. To reach these ambitious goals, this project is divided into seven work packages. Besides the project management work package, the remaining work packages are aiming towards the main objective of this project: forging turbine blades via a near conventional hot-die forging process for a test engine. Therefore an optimization of infrastructure, optimization of forging tools and development of robust process parameters are the main tasks.
Project Context and Objectives:
Work package 1:
Effective project coordination
Project risk management & management of project success criteria
Work package 2:
Benchmarking of ingot quality
Definition of ingot requirements
Approval of ingot manufacturer together with customer
Work package 3:
Optimization of existing infrastructure
Definition of optimized work flow
Work package 4:
Design of blades and forging equipment
Continuous improvement in forging (lessons learned)
Production of first article inspection hardware
Target cost calculation
Work package 5:
Selection of most economic forging die material for serial production
Definition of manufacturing and repair strategies and options for die lifetime improvement
Work package 6:
Definition of stable processing window
Work package 7:
Production of engine test hardware
Delivery of > 100 blades to customer
Project Results:
Work package 1:
Effective coordination of project team, partners and other relevant projects
Good communication between all involved parties
Organization of meetings and workshops
Project controlling
Financial and technical reporting
Project marketing at international conferences and through journals
Work package 2:
After first microstructural investigations of trial forgings, it was found that the billet needed to be improved. Simulation studies were conducted to find an optimized billet geometry. Together with the pre material source the results were discussed and the casting process was changed (see D2.2). First blade forgings were tested mechanically at different test labs.
Work package 3:
The upsetting press was upgraded with a new data recording system to meet aerospace requirements. A special chemical milling agent was designed together with a laboratory. A plant layout for an optimized work flow was created and an investment plan was calculated.
Work package 4:
Several production lots were forged within this work package. Continuous improvements were made by detailed lessons learned records after each forging lot. Discussions with the machining house started to optimize the forging geometry. Results are summarized in D4.5.
Work package 5:
A detailed investigation of different candidates for application as die material for the near conventional hot-die forging process was performed within this work package. A master thesis was written at IWS under coordination of BSTG. The results were presented at international conferences (D5.3).
Work package 6:
Robust process parameters were derived from forging trials in work package 4. Results of microstructure and geometry evaluations were analyzed within this work package. A method of manufacturing was defined (D6.4).
Work package 7:
The final work package dealt with the production of engine test hardware according to an approved Method of Manufacturing (D7.6). More than 100 blades were forged with the near conventional hot-die forging process and heat treated at BSTG (D7.7). After the shipping a detailed production cost evaluation was performed to show cost drivers (D7.8).
Potential Impact:
With the implementation of gamma-TiAl near conventional hot-die forged LPT blades a completely new market segment could have arisen for BSTG to increase turnover intensively. As the process established within this project is not stable for serial production and some billet material issues could not have been solved, it was not possible to meet the cost demands of the OEM. After the last trials Böhler Schmiedetechnik GmbH & Co KG feels confident to show the potential of a near conventional hot-die forging process. Böhler Schmiedetechnik GmbH & Co KG has paved the way for future investigations and the implementation of a cost effective near conventional hot-die forging process.
List of Websites:
www.bohler-forging.com
Coordinator:
Daniel Huber
daniel.huber@bohler-forging.com
The strong need for higher efficiency, reduced CO2 emissions and weight reduction in aircraft engines leads to a demand of innovative light-weight high-temperature resistant materials which can partly substitute the materials currently employed. Presently, Ni-base alloys are used for turbine blades in aero-engines which satisfy the high mechanical and thermal requirements. A disadvantage of Ni-base alloys, however, is their high density of about 8 g/cm3. Intermetallic titanium aluminides, which exhibit a low density of about 4 g/cm3, are certainly among the most promising candidates to meet the required thermal and mechanical specifications. During the last decade several “wrought” gamma-TiAl alloys have been developed. These alloys exhibit excellent mechanical properties, but show a narrow processing window. Böhler Schmiedetechnik GmbH & Co KG is specialized on forging processes of materials like Ni-base and Ti-alloys for aero engine applications with a high demand on structure mechanical requirements. In cooperation with the Department of Physical Metallurgy and Materials Testing at the Montanuniversität Leoben as well as other project partners a novel Nb and Mo containing gamma-TiAl based alloy (TNM alloy) was developed. Due to optimized microstructure the alloy showed good malleability in first forging trials. An innovative approach of near conventional hot-die forging, which means that conventional forging equipment with minor and inexpensive modifications can be used, was made by Böhler Schmiedetechnik GmbH & Co KG. Aim of this project is to develop a robust low-cost near conventional hot-die forging process for low pressure turbine blades which meet on the one hand the requirements of the OEM and give the right direction for future serial production on the other hand. To reach these ambitious goals, this project is divided into seven work packages. Besides the project management work package, the remaining work packages are aiming towards the main objective of this project: forging turbine blades via a near conventional hot-die forging process for a test engine. Therefore an optimization of infrastructure, optimization of forging tools and development of robust process parameters are the main tasks.
Project Context and Objectives:
Work package 1:
Effective project coordination
Project risk management & management of project success criteria
Work package 2:
Benchmarking of ingot quality
Definition of ingot requirements
Approval of ingot manufacturer together with customer
Work package 3:
Optimization of existing infrastructure
Definition of optimized work flow
Work package 4:
Design of blades and forging equipment
Continuous improvement in forging (lessons learned)
Production of first article inspection hardware
Target cost calculation
Work package 5:
Selection of most economic forging die material for serial production
Definition of manufacturing and repair strategies and options for die lifetime improvement
Work package 6:
Definition of stable processing window
Work package 7:
Production of engine test hardware
Delivery of > 100 blades to customer
Project Results:
Work package 1:
Effective coordination of project team, partners and other relevant projects
Good communication between all involved parties
Organization of meetings and workshops
Project controlling
Financial and technical reporting
Project marketing at international conferences and through journals
Work package 2:
After first microstructural investigations of trial forgings, it was found that the billet needed to be improved. Simulation studies were conducted to find an optimized billet geometry. Together with the pre material source the results were discussed and the casting process was changed (see D2.2). First blade forgings were tested mechanically at different test labs.
Work package 3:
The upsetting press was upgraded with a new data recording system to meet aerospace requirements. A special chemical milling agent was designed together with a laboratory. A plant layout for an optimized work flow was created and an investment plan was calculated.
Work package 4:
Several production lots were forged within this work package. Continuous improvements were made by detailed lessons learned records after each forging lot. Discussions with the machining house started to optimize the forging geometry. Results are summarized in D4.5.
Work package 5:
A detailed investigation of different candidates for application as die material for the near conventional hot-die forging process was performed within this work package. A master thesis was written at IWS under coordination of BSTG. The results were presented at international conferences (D5.3).
Work package 6:
Robust process parameters were derived from forging trials in work package 4. Results of microstructure and geometry evaluations were analyzed within this work package. A method of manufacturing was defined (D6.4).
Work package 7:
The final work package dealt with the production of engine test hardware according to an approved Method of Manufacturing (D7.6). More than 100 blades were forged with the near conventional hot-die forging process and heat treated at BSTG (D7.7). After the shipping a detailed production cost evaluation was performed to show cost drivers (D7.8).
Potential Impact:
With the implementation of gamma-TiAl near conventional hot-die forged LPT blades a completely new market segment could have arisen for BSTG to increase turnover intensively. As the process established within this project is not stable for serial production and some billet material issues could not have been solved, it was not possible to meet the cost demands of the OEM. After the last trials Böhler Schmiedetechnik GmbH & Co KG feels confident to show the potential of a near conventional hot-die forging process. Böhler Schmiedetechnik GmbH & Co KG has paved the way for future investigations and the implementation of a cost effective near conventional hot-die forging process.
List of Websites:
www.bohler-forging.com
Coordinator:
Daniel Huber
daniel.huber@bohler-forging.com