Nieuwe generatie van lichtgewicht mobiliteitsproducten en externe protheses

Iedere gram telt…

Geert Smits, Mifa Aluminium BV, Aalberts Industries NV

The Dutch population numbers 16.7 million inhabitants today• 4,7% (± 800,000 people) of Dutch

population need aids to enhance mobility• Cain• Crutch• Walking frame• Wheelchair

• 5,4% (± 900,000 people) of Dutch population use anatomic aids• Orthopedic shoes• Orthesis• Prosthesis

Data from CBS

Like everyone else• Stay active• Be independent• Have a social life• Have a professional career• Participate in sports

Mobility and anatomic aids• Designed according to their

individual needs• Shape• Size

…But everyone wants lighter aids

Easier to lift / push Competitive advantage Energy efficient

And stiffer. And more comfortable.

More efficient transfer of muscle power

Better absorbance of shocks

Translation of user requirements into the right material

• Light and strong - Specific Strength

Material selection by the Ashby approach

Translation of user requirements into the right material

• Light and strong - Specific Strength• 1. Magnesium Alloys• 2. Aluminium Alloys• 3. Titanium Alloys• 4. Steels

Material selection by the Ashby approach

Translation of user requirements into the right material

• Light and strong - Specific Strength• 1. Magnesium Alloys• 2. Aluminium Alloys• 3. Titanium Alloys• 4. Steels

• Light and stiff - Specific Stiffness• 1. Magnesium Alloys• 2. Aluminium Alloys• 3. Titanium Alloys• 4. Steels

Material selection by the Ashby approach

Translation of user requirements into the right material

• Light and strong - Specific Strength• 1. Magnesium Alloys• 2. Aluminium Alloys• 3. Titanium Alloys• 4. Steels

• Light and stiff - Specific Stiffness• 1. Magnesium Alloys• 2. Aluminium Alloys• 3. Titanium Alloys• 4. Steels

• Shock absorbent - Specific Damping Capacity• 1. Magnesium Alloys• 2. Steels• 3. Aluminium Alloys• 4. Titanium Alloys

Material selection by the Ashby approach

Pros and cons of Magnesium

• 40% lighter than Aluminium• 250% lighter than Titanium• 400% lighter than Steel• 30% better absorption of

vibrations than Aluminium

• Low deformability at room temperature

• Low corrosion resistance• No readily available

technology for manufacturing Magnesium parts

+ -

Total Performance Approach

Extrusion MachiningBending

Welding and assemblyFinished product Coating

Challenges: Extrusion• Optimization of die design• Optimization of billet

homogenizing treatments• Optimization of extrusion

temperature and speed• Determination of extrudate

strength

Challenges: bending• Determination of minimum

relative bending radius• Optimization of bending speed• Determination of spring-back• Optimization of bending

temperature

Bending at room temperature, speed 1 rpm

Bending at 150°C, speed 1 rpm

Challenges: Machining• Optimization of feed rate• Optimization of cutting speed• Optimization of depth of cut

Challenges: Coating• Optimization of pretreatments• Optimization of process

parameters• Optimization of lacquering step• Wear resistance of coating• Corrosion resistance of coating

Challenges: Welding and assembly• Optimization of pre-treatments• Optimization of filler feeding• Optimization of alternating current• Determination of joint strength

Phase II: Manufacturing and biomechanical testing of prototypes • Starts summer 2012• Selection of prototypes• Design of prototypes• Manufacturing of prototypes• Biomechanical testing of

prototypes

Sharon WalravenSilver medalist – Olympic Games Sydney 2000 (Ladies single)Gold medalist – Olympic Games Beijing 2008 (Ladies double)

Phase II: Manufacturing and biomechanical testing of prototypes • Novel ultra-light wheelchair for

tennis-star Sharon Walraven

Future spin-offs after completion of the project• Light-weight magnesium coated

profiles and parts for• High end sport bikes• Automobiles• Airplanes• Portable electronics

The members of the consortium would like to thank …..