Several prototypes and a set of Qualification Modules have been fabricated. To verify the exact form and dimension, mass, density and thermal expansion of the TMs (Test Masses), ex-situ measurements were performed at PTB's (Physikalisch-Technische Bundesanstalt)dedicated labs. The Sandvik polycrystalline diamond insert DCMW 11 T3 04FP CD 10 yielded the best results at a turning speed of Vc = 70 m/min, a feed of f = 0.02 mm/Rev, and an infeed of ap = 0.05 through 0.002 mm. To fabricate the flats a natural diamond Contur V1800 was used (Vc = 19 m/min, f = 10 mm/min, ap = 0.025 - 0.0005 mm). We applied the cooling lubricant Blasocut Kombi (mix ratio 4:1) at a pressure of 0.8 MPa. Even small deviations from the optimum turning parameters lead to ruptures of several micrometers depth and, as the removed material piles up at the tip of the cutting insert, even more material is removed from the surface. At optimum parameters we have been able to obtain a continuous chip of 3 micron thickness, only, thus achieving the best possible surface and form accuracy. Most dimensions of the manufactured TMs are compliant with the demanding requirements and show a discrepancy of about 1 micron only. The actual depth of the countersinks is off by several micrometers, the fabrication of which will be optimized for the next production. An average roughness of Ra < 0.2 micron (flats and faces) and Ra < 0.4 (shell) was achieved. The results are utilised to further improve the fabrication for the Flight Modules.
Fabrication and measurement development for precise test masses for the MICROSCOPE space project
Fertigungstechnische und messtechnische Entwicklung für genaue Prüfmassen zum Einsatz im MICROSCOPE-Weltraumprojekt
2009
4 Seiten, 2 Bilder, 4 Quellen
Aufsatz (Konferenz)
Englisch
Development of High Precision Test Masses for the MICROSCOPE Space Project
Tema Archiv | 2014
|Precise Measurement of Fuel Consumption on Engine Test Beds
Online Contents | 1993
Microscope: A Microsatellite for Equivalence Principle Measurement in Space
British Library Conference Proceedings | 2011
|Fabrication of a Precise Microwave Reflector
NTRS | 1983
|THERMAL VACUUM CHAMBER SYSTEM FOR PRECISE MEASUREMENT OF SPACE ENVIRONMENT
Europäisches Patentamt | 2024
|