TY - CONF A1 - Beck, Uwe A1 - Griepentrog, Michael A1 - Hertwig, Andreas A1 - Hielscher-Hofinger, Stefan A1 - Lange, Thorid A1 - Weise, Matthias T1 - Uncertainty budgets in surface technology: stepheigt, layerthickness, indentation hardness, adehesive strength N2 - The object (sample) and the measurement/testing procedure may always have unknown degrees of freedom, i.e. instead of 𝐯 ≥ n – 1 in many cases 𝐯 ≫ n - 1 may apply, in particular in the micro- and nano-world! T2 - 10. VDI-Fachtagung, Messunsicherheit und Prüfprozesse CY - Erfurt, Germany DA - 10.11.2021 KW - Methodology in metrology KW - Methodology in testing KW - Spectroscopic Ellipsometry KW - Instrumented Indentation Testing (IIT) KW - Centrifugal Adhesion Testing (CAT) PY - 2021 AN - OPUS4-53986 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Griepentrog, Michael A1 - Hertwig, Andreas A1 - Hielscher-Hofinger, S. A1 - Lange, Thorid A1 - Weise, Matthias T1 - Uncertainty budgets in surface techno-logy: step height, layer thickness, indentation hardness, adehesive strength N2 - The object (sample) and the measurement/testing procedure may always have unknown degrees of freedom, i.e. instead of 𝐯 ≥ n – 1 in many cases 𝐯 ≫ n - 1 may apply, in particular in the micro- and nano-world! T2 - 10. VDI-Fachtagung, Messunsicherheit und Prüfprozesse CY - Erfurt, Germany DA - 10.11.2021 KW - Methodology in metrology KW - Methodology in testing KW - Spectroscopic Ellipsometry KW - Instrumented Indentation (IIT) KW - Centrifugal Adhesion Testing (CAT) PY - 2021 AN - OPUS4-53739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Lange, Thorid A1 - Weise, Matthias A1 - Bartholmai, Matthias A1 - Schukar, Vivien A1 - Basedau, Frank A1 - Hofman, Detlef A1 - Köppe, Enrico T1 - From on line sensor validation to in-situ monitoring of layer growth: coatings around fibre bragg gratings N2 - The lack of on-line validation procedures for structure-embedded fiber-optical strain sensors, in particular fiber-Bragg-gratings (FBG), resulted in limited applications in structural health monitoring (SHM). Degradation under service conditions and ageing as a result of climatic influences or delamination under load were unsolved Validation issues. This could be overcome by means of an auto-diagnosis procedure based on FBG-sensors coated by electrochemical deposition (ECD) with a magnetostrictive NiFe-coating on top of an adhesive Cu/Cr adhesive layer deposited by physical vapour deposition (PVD) around the FBG strain sensor. This allows at any time under Service a validation of sensor functionality, stability, and reliability. For this purpose, a magnetic strain-proportional reference field is introduced. The optical read-out is realized by the measurement of the Bragg-wavelength shift. The ratio of resulting strain and exciting magnetic reference field should be constant given that the sensor is in proper function. In principle, the magnetostrictive coating around the FBG should also work as on-line magnetic field sensor and other applications in material science. One of these applications is the in-situ monitoring of ECD processes as the deposition of the ECD NiFe-layer on the FBG revealed. Challenges are the monitoring of temperature, deposition stages/thickness, and resulting mechanical stress under given plating conditions. Monitoring problems can be solved by applying a pre-coated FBG to the electrolytic process as the shift of the Bragg wavelength is affected by both the temperature of the electrolyte near the substrate and the stress formation in the growing layer. The experimental FBG set-up and the quantitative determination of temperature- and stress-related strain are described for a nickeliron electrolyte. The in-situ measurement of Bragg wavelength shifts of a pre-coated FBG during electrochemical deposition allows a detailed analysis of stress states due to changes in the growth morphology of the layer. The separation of mechanical and thermal contributions to this shift provides information on the individual Deposition processes in terms of a process fingerprint. T2 - ICMCTF 2021 San Diego/on-line CY - Online meeting DA - 28.04.2021 KW - Fiber- Bragg-gratings (FBG) KW - Physical vapour deposition (PVD) KW - Electrochemical deposition (ECD) KW - Magnetostrictive coating KW - ECD NiFe-layer PY - 2021 AN - OPUS4-52898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Hielscher-Hofinger, Stefan A1 - Hidde, Gundula A1 - Lange, Thorid A1 - Weise, Matthias A1 - Lerche, D. A1 - Rietz, U. T1 - Adhesion of Coatings vs. Strength of Composite Materials – A Review of Applications Evaluated by Centrifugal Adhesion Testing (CAT) N2 - Sufficient adhesion/tensile strength are basic requirements for any coating/composite material. For coatings, adhesive strength in N/mm2 is of Major interest for various applications such as decorative and water-repellent coatings on wood (paints and varnishes), optical coatings on glass and polymers (reflectors and filters), electrical coatings on semiconductors, glass and polymers (conducting and bondable layers), mechanical coatings on metals and polymers (wear-reduction, scratch-resistance) and adhesion-promoting layers. For composite materials, tensile strength in N/mm2 is also a key quantity for carbon fiber reinforced composites (CFC), laminates and adhesive-bonded joints. Centrifugal adhesion testing (CAT) transfers the single-sample tensile test from a tensile or universal testing machine into an analytical centrifuge as multiple-sample test of up to eight test pieces. The one-sided sample support instead of a two-sided sample clamping and the absence of mounting- and testing-correlated shear forces provides fast and reliable results both for adhesive strength and bonding strength by means of bonded test stamps. For bonding strength, the evaluation of failure pattern from microscopic inspection is required in order to determine the failure pattern according to ISO 10365 such as adhesive failure (AF), delamination failure (DF) and cohesive failure (CF). Hence, one test run by CAT-technology provides either statistics or ranking of up to eight samples at once. For adhesive strength of coatings, a variety of examples is discussed such as ALD-Al203 layers as adhesion promoters, evaporated Ag-layers on N-BK7 glass, sputtered Cr- and Al-layers on Borofloat 33 glass, evaporated Au-films on N-BK7 glass and sputtered SiO2 -layers on CR39 Polymer. Provided adhesive or bonding strength are high enough, the substrate or the joining part may also fail. T2 - Special PSE 2020 CY - Online meeting DA - 07.09.2020 KW - Centrifugal adhesion testing (CAT) KW - Adhesive strength KW - Pull-off test KW - Failure pattern KW - Compound strength PY - 2020 AN - OPUS4-51231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hielscher-Bofinger, Stefan A1 - Beck, Uwe A1 - Lerche, D. A1 - Rietz, U. T1 - Multiple-sample Testing: Adhesive Strength of Coatings and Bonding Strength of Adhesives evaluated by Centrifugal Adhesion Testing (CAT) N2 - The quantitative determination of adhesion and cohesion properties is a key requirement for adhesive-bonded joints and coated components in both R&D and Quality assurance. Because of the huge variety of layer/substrate Systems in terms of materials and large thickness range, adhesion tests display the same diversity as layer/substrate systems. There are only two tensile testing procedures available, that determine adhesive strength in terms of force per area (N/mm²), the single-sample pull-off test in a tensile testing machine and the multiple-sample-test using the Centrifugal Adhesion Testing (CAT) Technology. The CAT Technology is a testing method which uses centrifugal force as tensile testing force in a multiple-sample arrangement within a drum rotor of a Desktop centrifuge. Hence, the adhesive/bonding strength A/B can be determined on a statistical basis under identical testing conditions for up to eight samples. A variety of examples for bonding strength of adhesives, adhesive strength of coatings and compound strength of composite materials is discussed such as metalto-metal and glass-to-metal bonding, sputtered SiO2-layers on CR39 Polymer and carbon fiber reinforced polymer. T2 - Colloquium Department 6. CY - Berlin, BAM, Germany DA - 03.09.2020 KW - Centrifugal Adhesion Testing (CAT) KW - Adhesive strength KW - Bonding strength KW - Composite strength KW - Interlaboratory comparision PY - 2020 AN - OPUS4-51178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Hielscher-Hofinger, Stefan A1 - Lange, Thorid A1 - Stockmann, Jörg M. A1 - Weise, Matthias A1 - Rietz, U. A1 - Lerche, D. T1 - Centrifugal force meets materials testing – analytical centrifuge as multipurpose tool for tensile and compressive stress testing N2 - Up until several years ago, tensile and compressive tests have been exclusively carried out as single-sample tests within a tensile, hardness or universal testing machine. The availability of centrifuge technology changed this situation in 2013 in several ways because centrifugal force is used as testing force within a rotational reference frame. Firstly, multiple-sample strength testing became feasible for both tensile load condi-tions, e.g. determination of composite, bonding or adhesive strength, and compressive load conditions, e.g. hardness, compressibility and compactibility. Secondly, there is no need for a two-sided sample clamping and double-cardanic suspensions as samples are simply inserted using a one-sided sample support. Thirdly, shear forces can be avoided by means of guiding sleeves which steer test stamps acting as mass bodies for either tensile or compressive testing. Fourthly, up to eight samples can be tested under identical conditions within a very short period of time, typically within 15 minutes including sample loading and unloading. Hence, either a reliable statistics (of identical samples) or a ranking (of different samples) can be derived from one test run. The bench-top test system is described in detail and demonstrated that centrifugal force acts as testing force in an appropriate way because Euler and Coriolis force do not affect the testing results. Examples for both tensile strength testing, i.e. bonding strength of adhesives-bonded joints and adhesive strength of coatings, and compres-sive strength testing, i.e. Vickers-, Brinell- and ball indentation hardness and deter-mination of spring constants, are presented, discussed and compared with conven-tional tests within tensile, hardness or universal testing machines. At present, a maximum testing force of 6.5 kN can be realized which results at test stamp diameters of 5 mm, 7 mm, and 10 mm in tensile or compressive stress values of 80 MPa, 160 MPa, and 320 MPa. For tensile strength, this is already beyond bonding strength of cold- and warm-curing adhesives. Moreover, centrifuge technology is compliant to standards such as EN 15870, EN ISO 4624, EN ISO 6506/6507 and VDI/VDE 2616. Programmable test cycles allow both short-term stress and log-term fatigue tests. Based on a variety of examples of surface and bonding technology, applications in both fields R&D and QC are presented. Meanwhile, centrifuge technology is also accredited according to DIN EN ISO/IEC 17025. T2 - Intermationa Conference Dispersion Analysis & Materials Testing CY - Berlin, Germany DA - 22.05.2019 KW - Centrifugal Force KW - Compressive Stress KW - Tensile Stress PY - 2019 AN - OPUS4-48310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Griepentrog, Michael A1 - Hertwig, Andreas A1 - Weise, Matthias T1 - White light interference microscopy, ellipsometry, and instrumented indentation testing as reference procedures N2 - The paper addresses “WHITE LIGHT INTERFERENCE MICROSCOPY, ELLIPSOMETRY, AND INSTRUMENTED INDENTATION TESTING AS REFERENCE PROCEDURES“ and is subdivided in the following sections: 1. Measurement vs. testing vs. reference procedures, 2. White light interference microscopy (WLIM) for determination of step height h, 3. Spectroscopic ellipsometry (SE) for determination of layer thickness d and 4. Instrumented indentation testing (IIT) for determination of indentation hardness HIT. The following points are discussed in more detail: methodology of measurement and testing, uncertainty budgets for direct (WLIM), model-based (SE) and formula-based (IIT) reference procedures by means of specific examples. It is shown that standardization efforts are connected to reference procedures. T2 - Referenzverfahren CY - BAM, Berlin, Germany DA - 21.02.2018 KW - Reference procedures KW - Uncertainty budgets KW - White light interference microscopy KW - Spectroscopic ellipsometry KW - Instrumented indentation testing PY - 2018 AN - OPUS4-44256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Hertwig, Andreas A1 - Winkler, J. T1 - Preliminary work item (PWI) 23131 on standardization of ellipsometry N2 - The paper addresses the PRELIMINARY WORK ITEM (PWI) 23131 ON STANDARDIZATION OF ELLIPSOMETRY and the following points are discussed in more detail: Historical background of ellipsometry, Technical/industrial importance of ellipsometry and Standardization activities on ellipsometry. T2 - ISO TC 107 and JWG 4 meeting CY - Levi, Finland DA - 23.01.2018 KW - Standardization KW - Ellipsometrie KW - Modelling KW - Accreditation PY - 2018 AN - OPUS4-43959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Fischer, Daniel A1 - Hertwig, Andreas A1 - Hidde, Gundula A1 - Stockmann, Jörg M. A1 - Weise, Matthias T1 - Ellipsometric imaging of low-contrast surface modifications and depolarization contrast imaging (DCI) of particulate accumulations N2 - Imaging of surfaces regarding topographical, morphological, micro-structural, and chemical features is a key requirement for quality control for the identification of contaminated, degraded, damaged or deliberately modified surface areas vs. clean, virgin, undamaged or unmodified regions. As optical functions may represent any of these changes on the micro- and nano-scale, imaging ellipsometry (IE) is the technique of choice using either intensity, phase, or/and amplitude contrast for visualization of low-contrast surface modifications [1, 2]. Defects or surface and film features whether native or artificial, intended or unintended, avoidable or unavoidable as well as surface pattern are of interest for quality control. In contrast to microscopic techniques operated at normal incidence, ellipsometry as oblique-incidence technique provides improved contrast for vertically nano-scaled add-on or sub-off features such as ultra-thin transparent films, metallic island films, carbon-based thin films, laser modification or laser induced damage, dried stain, cleaning agent or polymeric residue. Two-sample reference techniques, i.e. referenced spectroscopic ellipsometry (RSE) may further increase sensitivity and decrease measurement time. In case of particulate accumulations depolarization contrast imaging (DCI) may improve the lateral resolution beyond the Abbe limit. This has been proven for silica spheres as reference in terms of single particles, particulate accumulations or particulate monolayers and layer stacks. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for reference measurements of particle diameter, particle height, or particulate layer/accumulation thickness. It has been shown that single silica particles of 250 nm in diameter, i.e. at least a factor of 4 better than the lateral resolution limit as of now, can be visualized on even substrates. However, the ellipsometric measurement of particle diameters of this size needs further efforts interpretation. T2 - Workshop Ellipsometry 2018 CY - Chemnitz, Germaný DA - 19.03.2018 KW - Low-contrast surface modifications KW - Particulate distributions KW - Imaging ellipsometry(IE) KW - Depolarization contrast imaging (DCI) PY - 2018 AN - OPUS4-44548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Baier, Jennifa A1 - Hidde, Gundula A1 - Sahre, Marion A1 - Weise, Matthias T1 - Particles in PVD-coatings: Imperfection or functional add-on feature? N2 - The application of PVD-coatings ranges from mechanical engineering, i.e. thicker tribological coatings, to precision optics, i.e. thinner optical coatings. For physical vapor deposition (PVD) technologies such as evaporation, sputtering, ion beam assisted/driven deposition, vacuum is a prerequisite for two reasons: at first process-related ones (evaporation source, plasma discharge, and mean free path) and at second coating-related ones (pure, perfect, and dense films). Usually, the goal is a homogenous coating of defined stoichiometry and micro-structure without any imperfection. However, the implementation of micro- or nano-particles may occur accidentally or delibe-rately. Independent of the particle origin, there are two fundamental rules regarding coating functionality: at first, the larger the particle diameter to coating thickness ratio the more affected the functionality of the coating, and at second, the larger the material contrast in terms of the functional feature of interest the more affected the coating performance. Hence, embedded particles have to be avoided for the majority of thin films by all means. The unintended implementation of particles usually results in a malfunction of the coating from the beginning or is at least considered as a weak point of the coating creating a time-dependent defect under service conditions. The intended implementation of particles on surfaces and in coatings may create add-on features, topographic ones and functional ones, however, the facts mentioned hold true. Examples of particle-initiated coating defects are demonstrated in dependence on the origin and the field of application. Strategies for deliberate attachment/embedding of particles on surfaces/in coatings are discussed regarding process compatibility and coating integrity. For industrial applications, both the validation of process compatibility of particle injection and the plasma resistance of particles under vacuum and plasma conditions have to be confirmed. Further points of interest are the homogeneity of particle distribution and the avoidance of particle agglomeration which is still a crucial point for dry dispersed particles. So far, technical applications are limited to PVD hybrid coatings, plasma dispersion coatings are still a challenge except for applications where homogeneity is not required as in case of product authentication. T2 - ICMCTF 2018, International Conference on Metallurgical Coatings and Thin Films CY - San Diego, CA, USA DA - 23.04.2018 KW - PVD-coatings KW - PVD-processes KW - Unintended particle generation KW - Particles as imperfections KW - Deliberate particle implementation KW - Particles as add-on features PY - 2018 AN - OPUS4-44973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -