Lean Manufacture Technologies

This part of the project will be oriented on development of new manufacture technologies to get savings in manufacture costs and manufacture time. However, the quality of engine components produced by innovative manufacture techniques must not be endangered. Durability of components must also be secured as the maintenance costs are the important source of DOC reduction.

Low-cost machining for compressors (WP 3.1)
Feasibility of development of resource-saving processes of manufacturing centrifugal compressor parts for gas turbine engines is stipulated by development of high-speed multiaxis machining of aviation materials, as well as by techniques of analysis, design, and manufacturing highly efficient cutting tools, and information technologies that ensure integral optimization of machining operations. The work will comprise the selection of the suitable turning and milling tools for compressor parts machining according to the material to be machined and the complexity of the part’s shape. Different cutting data of milling operation will be investigated and tested in order to obtain the best relationship between the machining time and the quality of parts.  Developmental work will focus on novel optimized strategy and modes of machining to reduce machining time and costs of the most labour-intensive centrifugal compressor parts, such as impeller and diffuser in particular.

Precise and low-cost casting technologies for turbine wheels (WP3.2)
Objective of technology developmental work is to find a cost effective casting technology for turbine wheels of small power class engines. The work will comprise the investigation of new materials in parallel with improvement of current used design approaches aimed at the realization of advanced high temperature resistant castings used as a structural casting. New casting materials will be new nickel based super alloys with higher heat corrosion characteristics and with modified mechanical properties to be used in higher temperature range than is usual today in aircraft engines. Current state of heat resistance is 950°C for alloys such as IN 713LC and IN792 5-A which will be taken as base line material for comparison. Based on this chemical composition (for example Wolfram content will be optimised and it’s negative effects will be negotiated by carbon, aluminium and titan content) the casting material will be modified in order to achieve improved heat resistance preliminary defined 1050°C.
Based on numerical simulation of casting process we can achieve better quality control of the casting process. Subsequently the scrap rate can be reduced by approx. 10%. Better efficiency of the parts production brings a reduction in part price by 8% with current part quantities required for the engine. It can be even more significant with increased part numbers.

Development of progressive coating solutions for engine parts (WP3.3)
The aim is to develop new TBC (Thermal Barrier Coating) technology. Two approaches would be considered:
a) the use of new nanostructured zirconia based materials for TBC deposition
b) the use of HFPD (high frequency pulse detonation) technology to deposit dense, erosion resistant and high performance zirconia top coats in single and/or multilayered structures
The work will comprise the implementation of commercial solutions whose potential has already been explored for application in large engines. For this purpose, novel thermal spray processes based on the HFPD and a new hybrid high velocity combustion (OFI, from Oxy-Fuel Ionisation) spray technologies will be investigated. Both technologies represent cost-competitive solutions for the thermal spray systems. Novel composite materials for compressor blade roots to replace existing CuNiIn coatings will be also addressed by RTD work of ESPOSA. These new materials are based on blends of HT corrosion resistant cobalt alloys and solid lubricants such as Hexagonal Boron Nitride (hBN). Development of novel ceramic materials for TBC applications under extreme service conditions with optimised architecture in the nano-scale will also be part of RTD work.

Low-cost gearbox manufacturing (WP3.4)
Main intention is to develop more cost efficient manufacturing technologies without compromising performance of the gearbox.  Efforts will be focused on improvement of finishing processes of transmission elements which are in fact the most time consuming operations. Moreover the most energy consuming operation like heat treatment and quenching will be reviewed to select most efficient technology available. The contour induction hardening process (CIH) was selected in order to reduce energy consumption during the heat treatment process. The use of CIH for gearwheels will be investigated as this process gives the promises of the best choice between cost and performance. CIH process has the potential to generate a shape and thickness of hardened layer similar to classical carburization process.  However, the difficulties to achieve such results with conventional trial and error process tuning approach have limited the use of CIH technology in the aviation industry so far. Reduction of the machining time is a second area of improvement which will be addressed by comparison of all most recently used processes, but not limited to, like superfinishing, honing by Red ring, and by Fassler processes and precise grinding. All these methods will be evaluated to find the optimum ratio between the finishing costs and performance. Samples will be made using above mentioned methods and tested to determine wearing resistance.