1. By Marcel van Wonderen Process Technology Department Central Engineering KLM Engineering & Maintenance Schiphol-Airport The Netherlands

2.

Content

Introduction

Chronological

Pictures

Details

Features

Metallurgical results

Applications

Conclusions

Developments

3. 4. KLMs chronological order of acquiring thermal spray equipment: - 69/70: Flame spray equipment (including fusion), in a brick room with water curtain - 1972: Plasma spray equipment (handheld gun, turntable, powder feeder, manual control console) - 1987: First robotized plasma cabin with PLC control (first Airline in Europe) - 1992: Programmable special purpose plasma spray machine for Fan disks - 1997: New cabin for electric arc spraying at the B&V department- 1995: New dust collecting & filtration system for the brick room - 1998: Upgrade of plasma spray equipment towards CE marking - 1993: Introduction of electric arc spraying - 2004: New State of the Art robotized spray cabin with unique features(like high efficiency plasma) - 1999: New multi functional turntables- 2001: New PLC programmable horizontal and vertical traverses - 2005: First to get new closed loop electric arc spray system of Praxair-TAFA type 9935 5. Improvements needed : High amount of fume and dust emission. Lower than desired deposit efficiency Process Instability ; a) Voltage output fluctuations b) Possible feed rate changes, arcing, micro-welding of wires to the current transfer tips c) Changes of atomizing airflow rateCoating non-homogeneity, inclusions of unmelts and sometimes high porosity ; a) Electrical voltage parameters ripple and pulsation;b) Instability of wire feeding; arcing; c) Instability of airflow rate mentioned aboveImproper control or lack of control; a). Feedback voltage and air pressure or flow rate signals are taken from the console b). Air hose restrictions, resistance and bending are nottaken into account.c). Electrical resistance of power leads and their connections to a power sourceand to a gun are not taken into account. High incoming air supply pressure ; Big pressure drop inside control systems requires high incoming pressure. Often only 80-90 psi (5.56.2 bar) of air pressure is available. Therefore more difficult of producing as dense a coating as possible 6. Picture at the ITSC05 in Basel, Switzerland: KLM purchases first type 9935 closed loop electric arc spray system of Praxair-TAFA 7. Detail pictures of the 9935 CoArc: 8. Features of the new 9935 Praxair-TAFA Closed-loop electric arc spray system:

Touch screen operators console

Lower atomizing voltage spraying

Ultra high air flow capability

Voltage and air pressure measuring at the gun head

Wire usage counter and out monitor

Recipe storage

Data acquisition

Higher deposit efficiencies

Low, HVOF-like coating porosity and low oxide levels

Pull and push-pull configurations

9. Metallurgical and tensile bond strength results of the new 9935 Praxair-TAFA closed loop electric arc spray system : Example of Cupper-Zinc-Silver alloy CuZnAg: tensile bond strength average64 N/mm 2 (min. req. is 20,7 N/mm 2ref. GE SPM 70-49-44) Non-Heat Treated Heat Treated 2 Hours at 399C Heat Treated 2 hours at 468C 10. Examples of Inconel 718, Nickel-Aluminum and Cupper-Nickel-Indium: Evaluation according GE SPM 70-49-xx Evaluation according GE SPM 70-49-yy Evaluation according GE SPM 70-49-zz 11. Voltage during spraying with traditional system Voltage during spraying with new state of the art closed loop electric arc spray system 12. Typical applications:

Parts: Coatings: Function:

- HPC stator caseAl Abradable

- CRF Inc 718 Dimensional rest.

- Fan frame assy NiCrAl Dimensional rest.

- Cooling & Vent Seal CuZnAg Abradable

- Fanblades CuNiIn Anti-fretting

- #1Bearing Housing Mo Anti wear

- Housing Sump 4 brg NiAl Dimensional rest.

13. Conclusion - KLM is investing in new State-of-the-Art thermal spray equipment in order to establish a center of excellence in thermal spraying within the Aircraft MRO market. - KLM wants to stay in the front line of new developments 14. Future :

Testing Zinc and Aluminum spraying on compositeAircraft materials as anti-static coating

Testing new (cored) wires for Aircraft Industry

New light gun (only push system). EM-14

Development of internal spray gun.