Development of micrometer-sized specimen production processes for nonconductive materials
Research output: Thesis › Diploma Thesis
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Abstract
The position resolved measurement of mechanical properties of materials allows a mapping of inhomogeneities and enables us to draw conclusions about the local composition, damage evolution and microstructure. The motivation for this work came from the prospect of gaining a better insight into the ageing mechanisms of fluorinated ethylene propylene (FEP) in low earth orbit (LEO) environment, which can lead to severe embrittlement of the polymer. FEP is widely used in form of foils for the outermost layer of the multi layer insulation (MLI) of spacecrafts. In this function, FEP is exposed directly to the LEO environment. The aim was to produce flat tensile specimens with a thickness of a few tens of micrometers, to be able to resolve a possible gradient in the mechanical properties within the 127 µm thick FEP outer layer of MLI, which was retrieved from the Hubble Space Telescope. Various types of micro machining methods were tested and assessed. The use of a microtome and an ion milling system proved to give the best results in respect to cheap and relatively fast specimen production. The well reproducible specimens were tested in tensile tests under an optical microscope and the results were then complemented by spectroscopic measurements.
Details
Translated title of the contribution | Entwicklung eines Probenfertigungsverfahrens für nichtleitende Materialien mit Abmessungen im Mikrometerbereich |
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Original language | English |
Qualification | Dipl.-Ing. |
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Award date | 27 Jun 2014 |
Publication status | Published - 2014 |