AIRBUS HELICOPTERS Oil Deflector

AIRBUS HELICOPTERS Oil Deflector

Historic

In order to achieve consistent, repetitive results, a manual intervention is required in the last forming step therefore skilled people are still an active part of this process.

Manufacturing the Oil Deflector first involves a multi-pass forming process, then a thermal treatment is applied to an Aluminium 6061 T0 blank  to achieve a T4 temper. During this process internal stresses are liberated generating deformations requiring an additional calibration step using the elasto-press. Manual rework is then often needed to finish the part (after the deep drawing process) and cannot be done using mechanised tools.

AIRBUS HELICOPTERS – A technical dream

AIRBUS HELICOPTERS has mastered this procedure to achieve the desired results yet the complexity of the range, the cost of production, the waste and the cycle times can ultimately render this part ineffective to guarantee quality robustness and compete economically.

The options were to:

• Remove heat treatments
• Reduce the number of different manufacturing steps
• Reduce the number of repeated manual operations
• use other materials

This had to be done in strict accordance with quality and dimensional performance standards to improve production.

Why this seemed difficult to achieve?

Trying to do this using only conventional production methods would be extremely difficult as they dictate many technical limitations, such as the drawing depth before rupture, stress pocket distribution and required multi-pass forming and additional heat treatments.

Working in partnership

Technological advances and innovations usually come from grouping diverse fields of expertise. AIRBUS HELICOPTERS understands what is at stake and therefore actively put in place a partnership with Bmax, a company specialising in high-speed deformation solutions for metal work:  assemblies and implementations through Ultra High-Power impulse electrical discharges that enables deeper drawing of the flat sheet needed to achieve final temper state using less steps and rework.

The team from left to right:
D. Alleman (Bmax); Dr G. Avrillaud (Bmax); Dr Delphine Alléhaux (AIRBUS HELICOPTERS): Material Processes Engineer – Responsible for New Technological Development; Robert Ré (AIRBUS HELICOPTERS) Head of Industrial Innovations and Deployment Structures; J. Bonafe (Bmax), M. J. Jimenez (Bmax Agent – France)

AIRBUS HELICOPTERS X3 demonstrator test flight (Image: Copyright AIRBUS HELICOPTER – Patrick Penna)

The increasing number of new and composite materials needed in the design and manufacture of aircraft parts requires those specialising in assembly procedures and the deformation of metallic materials, to be even more innovative in order to improve performance, robustness and competitiveness.

Bmax Solutions

Bmax specializes in Indirect and Direct Magnetic Pulse Forming as well as Electro-Hydraulic Forming technologies. After consideration, Electro-Hydro-Forming (EHF) was chosen to develop the part due to:

– The size of the parts to be produced
– The complexity of the shape

EHF is a process used to form metal at Ultra high-speeds using shock waves created in an aqueous environment through high-voltage electrical discharges.

For this project, the blank material of hardened T4 strength Aluminium (AI 6061) was supplied. Where normally AIRBUS HELICOPTERS uses two dies on the elasto-press here a single forming die was used.

The forming was then achieved through multiple discharges in a one step process.

The Results

The Oil Deflector was precisely and accurately formed with no manual intervention, no heat treatments and accomplished up to 35% elongation where normally elongation at rupture occurs at only 15% with traditional forming methods.
This project is a great success for the AIRBUS HELICOPTERS and Bmax teams who rose to this considerable technical and economical challenge through a shared passion for breaking conventional boundaries.