TY - CONF A1 - Rietz, U. A1 - Lerche, D. A1 - Beck, Uwe A1 - Hielscher, Stefan A1 - Kern, Janine T1 - Determination of bonding, adhesive and composite strength by means of centrifuge technology N2 - The quality and durability of bonded joints, coated systems and composites depend on various factors. Therefore effective quantitative tests to determine adhesive, bonding or composite strength are of great need for R&D and QC. In this paper a new measuring principle is described which uses the centrifugal force to generate the test load. By the geometry of the whole measurement set-up, the test specimen are supported from only one side, the influence of shear forces is avoided. The possibility to test up to eight samples in one measurement under identical testing conditions allows a high sample throughput. A detailed description of the whole sample preparation procedure including pre-treatment is followed by the specification of the measuring protocol as well as result analysis. For each application area bonding strength of joints, adhesive strength of coated systems and internal strength of composite materials examples are presented. T2 - EURADH 2014 - 10th European Adhesion Conference CY - Alicante, Spain DA - 22.04.2014 KW - Adhesive strength KW - Bonding strength KW - Composites KW - Centrifuge technology KW - Zentrifugentechnologie KW - Klebfestigkeit KW - Haftfestigkeit KW - Mehr-Proben-Prüfen/Kleben PY - 2014 SN - 978-84-616-9067-1 SN - 84-616-9067-2 SP - Paper 47, 203 EP - 206 AN - OPUS4-31311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beck, Uwe A1 - Reiners, Georg A1 - Lerche, D. A1 - Rietz, U. A1 - Niederwald, H. T1 - Quantitative adhesion testing of optical coatings by means of centrifuge technology N2 - Although adhesion testing of coatings is of fundamental interest for quality assurance, it is still a challenge regarding reliable quantitative results. Because of the huge variety of coating/ substrate systems in terms of materials and thickness range, adhesion tests display the same variety as coating/substrate systems. Some tests are qualitative, many are quantitative but except for the pull (DIN EN ISO 15870) and pull-off test (DIN EN ISO 4624) adhesion is not measured in terms of force per area. For optical coatings, the standardized tests according to ISO 9211-4 apply, i.e. abrasion tests (cheese cloth or eraser test) and adhesion tests (tape or cross-hatch test) with different degrees of severity. Instead of the adhesion strength, all these single-sample tests provide only quantitative information on the abrasion or adhesion resistance of a particular coating/ substrate system. The centrifuge test has manifold advantages. First, it can be easily run as multiple-sample test. Second, adhesion strength is measured in absolute numbers (N/mm2). Third, the centrifuge test requires only a one-sided sample support instead of a two-sided sample clamping as the pull- and pull-off test do. Fourth, it is much easier and faster than many other tests. Fifth, the centrifuge technology additionally enables tests under defined climates or harsh environments. Last but not least, versatile test conditions (alternating loads at various load rates) important to fatigue testing can be easily realized by varying the number of revolutions. The centrifuge test was applied to the testing of optical coatings on glass and CaF2. It could be shown that there are significant advantages compared to other tests. In particular, the centrifuge test was able to discriminate the adhesion strength for coating/substrate systems until failure which all passed the standardized tests of ISO 9211-4. KW - Adhesion strength KW - Bonding strength KW - Optical coatings KW - Pull-off test KW - Centrifuge test KW - Quantitative adhesion testing PY - 2011 U6 - https://doi.org/10.1016/j.surfcoat.2011.02.016 SN - 0257-8972 VL - 205 IS - Supplement 2 SP - S182 EP - S186 PB - Elsevier Science CY - Lausanne AN - OPUS4-23285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rietz, U. A1 - Lerche, D. A1 - Hielscher, Stefan A1 - Beck, Uwe T1 - Centrifugal adhesion testing technology (CATT) - A valuable tool for strength determination N2 - A new technology for strength determination of adhesive-bonded joints based on analytical centrifugatioon is introduced. Tensile as well as shear strength can be measured for multiple test specimens simultaneously within a very short time. The experimental procedure is described from sample preparation, application of adhesives, sample mounting within the centrifuge to testing parameters and sequences. All requirements of DIN EN 15870 are fulfilled and, in addition, a higher throughput and a better reproducibility can be obtained. The experimental results are discussed regarding bonding strength development over time, comparison of tensile and shear strength and various testing conditions. Furthermore, an additional application field of centrifuge technology is described with respect to the determination of the adhesive strength of coatings. The novel centrifuge based technology provides the determination of bonding, adhesive and shear strength on a statistical basis under identical testing conditions for up to eight samples. Moreover, sophisticated two-sided sample clamping, necessary for a tensile testing machine, is replaced by a simple plug-in procedure. KW - Centrifuge technology KW - Adhesive strength KW - Interface strength KW - Bonding strength KW - Adhesion KW - Tensile strength KW - Shear strength KW - Centrifuge KW - Multiple sample testing PY - 2015 SN - 0916-4812 SN - 0001-8201 VL - 51 IS - S1 (Special Issue on WCARP-V) SP - 293 EP - 297 PB - Kyokai CY - Osaka AN - OPUS4-33994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -