LOW GRAVITY TEAM
REXUS 15/16
Main parts of our project
The experiment is concerned on studying the physical deformations and properties of alloys after being melted and welded in a sounding rocket. The process will take place during the miligravity period that is after the yo-yo de-spun and the motor separation. We require a de-spun environment because of the high degree of precision needed in our method: the laser and the optical system will be aligned in such a manner that the focused laser light points at the target (the alloy sample).
More details about our experiment and the winning article at International Astronautic Congress (IAC 2013) for "The best Team Project" can be found here.
Laser and Lenses
Laser & Lenses
After some calculus we decided to use a LASER diode of minimum 5W focusing to a spot of 0.1 mm diameter. The students from Polytechnic University of Bucharest melted the samples with a CO2 laser at The National Institute of Lasers, Plasma & Radiation Physics (INFLPR) while those from Durham used laser diodes.The experiment at University of Durham was concerned on focusing the LASER beam in order to obtain melting processes at low output power.
1 plano convex cylindrical lens
-1046nm anti-reflective coating on them to minimise reflections and power absorption
-The samples were placed in front of the lens.
-The laser beam spot was elliptical
-Aware of the LIDT ( Laser Induced Damage Threshold)
Set-up and Electronics
Set-up & Electronics
The experiment will contain a box where we are going to place the instruments (the LASER, the sensors, the camera, the LEDs etc.). On a rail, we are going to mount several materials of different thickness in front of the laser beam. The samples will be placed vertically and will move during the flight through a servo-motor. The altitude and the temperature will be constantly measured. We will also use an accelerometer to monitor the changes of gravity.
Materials and Results
Materials & Results
Expected results in miligravity:
1. Abnormal flow of liquid metal
2. Changes in microstructure
3. Thermocapillary convection
4. Dendritic growth
Interesting materials for space industry:
a).Low temperature Pb- free solder
b).Aluminun alloy (Al6061)
c). Titanium alloy (Ti64 and Ti6Al4V)
Because we are expecting to get advice from the best specialists from ESA, DLR, MORABA and SNSB about our SED, we will publish it after the workshop. Until then we give you the Abstract of our experiment and our Proposal.
You are also invited to have a look on our presentation, held in Holland.
Just a sample of our work. To see more or discuss about our experiment please contact us!