In this work we demonstrate how absolute length measurements by interferometry, as used for regular gauge block calibration, can be applied to measure the dimensional drift behavior of connections joined by gluing or screwing and how these joining techniques are influenced by thermal treatment. While it is common to investigate the intrinsic stability of material samples by repeated length measurements, there exist growing demands in precision engineering to characterize the stability of assemblies, i.e. of joined material pieces. In order to enable investigation of joining techniques representative joints were fabricated by a number of methods as wringing, screwing and gluing. By using gauge block shaped samples as joining parts parallelism and flatness could be achieved which is needed for interferometric length measurements. The stability of the joints has been investigated longitudinally and laterally to the connection interface, and also mutual tilting of the parts was detected by analysis of the phase topographies. With the use of sample joints, the behavior of connection elements used in ultrahigh-precision instruments can now be examined on an accuracy level of about one nanometer. Results of approximately one year of observation show that screwed joints do not exhibit a significant change of length or orientation. They also did not show response to temperature variations of ±10°C, which is different for adhesive joints where dimensional changes of up to 100 nm were observed.

Date Published: 27 August 2014
PDF: 8 pages
Proc. SPIE 9173, Instrumentation, Metrology, and Standards for Nanomanufacturing, Optics, and Semiconductors VIII, 91730B (27 August 2014); doi: 10.1117/12.2060382

Published in SPIE Proceedings Vol. 9173:
Instrumentation, Metrology, and Standards for Nanomanufacturing, Optics, and Semiconductors VIII
Michael T. Postek, Editor(s)