TY - CONF A1 - Beck, Uwe A1 - Hielscher, Stefan A1 - Lange, Thorid A1 - Rietz, U. A1 - Lerche, D. T1 - State-of-the-Art in Multiple-Sample Evaluation of Adhesive and Bonding Strength N2 - The paper addresses the “State-of-the-Art in Multiple-Sample Evaluation of Adhesive and Bonding Strength” and the following points are discussed in more detail: 1. Motivation (coatings, varnishes, tapes, laminates, CFRP, adhesive-bonded joints) 2. Conventional single-sample testing (evaluation of adhesive and bonding strength; failure pattern) 3. Multiple-sample handling (MSH), bonding (MSB), and testing: centrifugal adhesion testing (CAT) (multiple-sample approach, tensile test within a centrifuge) 4. Application examples of CAT-Technology™ (laminates, optical coatings, CFRP joints) Finally, a summary is given regarding status quo and benefits of CAT-technology under tensile stress conditions whereas examples of testing in a centrifuge under compressive stress conditions are mentioned in the outlook. T2 - The 5th International Conference Competitive Materials and Technology Processes CY - Miskolc-Lillafüred, Hungary DA - 08.10.2018 KW - Centrifugal Adhesion Testing KW - CAT KW - Multiple-sample handling (MSH) KW - Multiple-sample bonding (MSB) KW - Tensile strength of laminates KW - Tensile strength of coatings KW - Adhesive strength KW - Bonding strength PY - 2018 AN - OPUS4-46336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Hidde, Gundula A1 - Lange, Thorid A1 - Gargouri, H. A1 - Kärkkänen, I. A1 - Naumann, F. T1 - Plasma Activation and Plasma-assisted ALD Surface Modification of Polymers for Improved Bonding and Adhesive Strength N2 - Bonding strength is crucial on polymers of low surface energy, for clean surfaces limited to 0.5, 1, and 2 MPa for PTFE, PP, and PE. Plasma treatment may improve bonding strength by a factor of 2 (PTFE) or 5 (PP and PE). The efficiency of treatment is usually 10% as both low pressure and atmospheric pressure processes show low topographic conformity. Besides, lifetime of activation/modification is rather short. Hence, bonding has to be carried out immediately after plasma treatment. The concept of plasma-assisted ALD (atomic layer deposition) interlayers was introduced in the project HARFE of SENTECH (modification/deposition/in-situ monitoring) and BAM (bonding, characterization, testing). ALD deposition has a high surface conformity and for dielectric films of Al2O3 also a good long-term stability given that the films are dense enough. Based on TMA and O2/O3 precursors, ALD layer stacks from 60 to 375 monolayers were prepared under different conditions. For a transfer time of 24 hours from deposition to measurement, bonding strength could be increased up to 5 MPa (PTFE) respectively 10 MPa (PP, PE). The huge potential of ALD layers as adhesive interlayers was demonstrated for Al2O3 on stainless steel with bonding strength beyond 15 MPa, i.e. interface strength within the ALD stack is also in this range. This is a prerequisite for subsequent PVD/CVD-deposition in hybrid systems. By means of the SI ALD LL system of SENTECH thermal and plasma-supported ALD processes can be alternatively realized. Ellipsometric in-situ monitoring provides monolayer sensitivity and reveals that the efficient bonding of the lower ALD layers on the polymer has to be further improved. Testing of bonding strength was realized by CAT (centrifugal adhesion testing) technology. It was shown that ALD modification correlates with the increase of surface energy and bonding strength. T2 - PSE 2018 - 16th Conference on Plasma Surface Engineering CY - Garmisch-Partenkirchen, Germany DA - 17.09.2018 KW - Plasma activation KW - Plasma-assisted ALD modification KW - Adhesive ALD interlayer KW - Bonding strength KW - Adhesive strength PY - 2018 AN - OPUS4-46015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -