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Organisationseinheit der BAM
- 6 Materialchemie (47)
- 6.7 Materialsynthese und Design (45)
- 8 Zerstörungsfreie Prüfung (6)
- 8.6 Faseroptische Sensorik (6)
- 6.1 Oberflächen- und Dünnschichtanalyse (4)
- 6.2 Material- und Oberflächentechnologien (4)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (4)
- 1 Analytische Chemie; Referenzmaterialien (1)
- 1.5 Proteinanalytik (1)
- 6.6 Physik und chemische Analytik der Polymere (1)
Eingeladener Vortrag
- nein (130)
Auf Basis einer Literaturstudie werden der Stand und die Perspektiven des Recyclings beschichteter Bauteile vorgestellt. Die Studie ist verfahrens-, branchen- und produktübergreifend angelegt. Die gesetzlichen Rahmenbedingungen werden erläutert, eine Auswahl beschichteter Bauteile und Materialkombinationen bezüglich ihrer Recyclingfähigkeit untersucht und unterschiedlichste Recyclingverfahren diskutiert. Auf die Bedeutung des Recyclings beschichteter Bauteile als spezieller Verbundwerkstoff wird eingegangen.
Glühentladung optischer Ausstrahlungsspektroskopie (GDOES) wurde ursprünglich für die elementare Analyse von Größenmaterialien entwickelt. Mehrere Gruppen führten diese Methode zur Analyse von Anstrichen, Laienstapeln und dünnen Filmen durch. In den frühen Neunzigern wurde eine ISO-TC 201-Arbeitsgruppe gegründet, um Normen für alle Formen der Glühentladungsspektroskopie (GDS) zu entwickeln und die Fähigkeiten der Oberflächenchemikalien-Analyse zu beurteilen, insbesondere für die Tiefe von gestuften Systemen. Die Quantifizierung von Tiefenprofilen, d.h. die Umwandlung von Intensitäts-Zeit- Profilen in Konzentrierungs-Tiefen-Profile ist für dc-mode entwickelt worden. 1997 wurde ein VAMAS TWA 2 Vorschlag für ein Referenzanstrich für GD-OES Tiefe gemacht. Entsprechend dem VAMAS Beurteilungsverfahren wurde dieser Vorschlag 1998 mit einigen geringfügigen Änderungen genehmigt.
Sicherheit bei der Produktion von Lebensmitteln: Eigenschaftsanalyse von sterilen Oberflächen
(2005)
CdSe films grown on Ti-coated polished steel by constant-current deposition from an aqueous solution containing selenosulfite and cadmium nitrilotriacetate have been studied by spectroscopic ellipsometry under in-situ conditions. Ellipsometric parameters, tan? and cos?, were measured both as a function of deposition time at ? = 825 nm and of wavelength (? = 500-900 nm) for constant film thickness from 0.02 µm to 2.3 µm. The model used for data analysis, Ti-substrate | TiO2 | CdSe-film | solution, with optically homogenous phases was valid for film thickness larger than 0.3 µm. Refractive indices and extinction coefficients of the 2.3-µm film were derived for ? = 500900 nm. A direct band-gap of 1.72 eV was determined. The faradaic efficiency of electrodeposition was 0.93 for a current density of 50 µA cm-2.
Nanotechnologien werden gegenwärtig als leistungsfähige Oberflächentechniken in erheblichem Umfange industriell genutzt. Dabei spielen dünne Schichten und deren Kenndaten eine wesentliche Rolle, z.B. als Röntgenspiegel oder optische und magnetooptische Datenträger. Die Schichtdicke zählt hierbei zu den technologisch wichtigen Parametern. Abgeleitet von Anwenderinteressen, werden für die Röntgenreflektometrie (XRR bzw. GIXR), Elektronenstrahl-Mikroanalyse (EPMA) und Röntgenfluoreszenzanalyse (XRF) einerseits und die Ellipsometrie andererseits zugeschnittene Schichtdickenmaßverkörperungen (SDM) entwickelt, gefertigt und untersucht. Das Ziel ist die Bereitstellung praxistauglicher, kalibrierter SDM, im weiteren Schichtdickennormale (SDN) genannt. SDN sind Maßverkörperungen, für die der Schichtdickenwert mit einer definierten Messunsicherheit bekannt und auf ein metrologisch anerkanntes Längennormal zurückgeführt ist. Berichtet wird über die Herstellung und messtechnische Charakterisierung der beiden spezifischen Varianten von Maßverkörperungen.
Bestimmung der Topographie technischer Oberflächen und der Haftfestigkeit an beschichteten Bauteilen
(2005)
Einsatz der Oberflächentechnik zur Verbesserung der Ausbrennsicherheit von Sauerstoffarmaturen
(2007)
Decorative optical coatings
(1994)
Decorative hard coatings: interdependence of optical, stoichiometric and structural properties
(1993)
Dielectric and electromechanical properties of the cellular polypropylene ferroelectret films (EMFIT), combining strong piezoelectric response with a low density and softness, evidence their high potential for the air-coupled ultrasonic applications. The disadvantage of the low coupling factor is compensated by the extremely low acoustic impedance, which provides excellent matching to air and promises efficient sound transmission through the airtransducer interface. The influence of the electrodes on the electromechanical properties was investigated. Electron beam evaporation technology was adapted to the EMFIT films, and films with both-sided Au and Al electrodes were prepared without reducing or suppressing of the electromechanical properties. Finally, prototype transducers based on the EMFIT films were developed. In spite of the simple construction and absence of matching layers, high sensitivity of the EMFIT transducers was proved in the air-coupled ultrasonic experiment. Amplitude and delay time scanned images of the polyethylene step wedge with holes, obtained in both pulse-echo and transmission modes, demonstrate that non-contact ultrasonic imaging and testing with EMFIT transducers is possible.
Centrifuge Technology: A Promising Tool for the Determination of Adhesion and Mechanical Properties!
(2007)
Herstellung, Charakterisierung und Zertifizierung von Referenzschichten für die Oberflächentechnik
(2005)
The new promoted ignition combustion test apparatus at BAM matches the requirements of ASTM test method G 124 [ASTM G 124, Standard Test Method for Determining the Combustion Behavior of Metallic Materials in Oxygen-Enriched Atmospheres, 2003] and of EIGA publication, IGC Doc 13/02/E [EIGA Gas Association Document IGC Doc 13/02/E, Oxygen Pipeline Systems, 2003]. The test apparatus is most likely the only one in Europe. The test chamber allows investigations with pure oxygen or oxygen mixtures at pressures up to 500 bar and at temperatures up to 400°C at static or flowing gas conditions. The ignition device consists of an electrical ignition wire and a promoter. IR-sensors, distributed over the whole length of the rod, measure and record the burning temperature and allow measurement of the burn rate. A video system records the experiment for visual characterization of the burning behavior. BAM test results are compared with published data. Results on investigations with coated rods are presented. Ceramic coatings seem to be a solution for the use of certain less compatible metallic materials at higher oxygen pressures.
Two different test apparatuses are used at BAM to evaluate the safety of oxygen components: First, the promoted ignition combustion test according to ASTM G 124 [1] and to EIGA IGC Doc 13/02/E [2], and second, the new metallic disk ignition test that has not been standardized yet. The standard test method ASTM G 124 allows a ranking of metallic materials for use at high pressure oxygen. However, the transfer of those test results to valves and fittings in real-life situations is rather complex. The metallic disk ignition test, developed at BAM, is more practice oriented and uses metallic disks of different thicknesses of the investigated material. A commonly used nonmetallic sealing ring is placed in front of this disk and serves as an igniter. This test array is then exposed to high pressure gaseous oxygen impacts in a standardized pneumatic impact tester according to DIN EN 1797 [3].
High-accuracy film thickness measurements in the range below 100 nm can be made by various complex methods like spectral ellipsometry (SE), scanning force microscopy (SFM), grazing incidence X-ray reflectometry (GIXR), or X-ray fluorescence analysis (XRF). The measurement results achieved with these methods are based on different interactions between the film and the probe. A key question in nanotechnology is how to achieve consistent results on a level of uncertainty below one nanometre with different techniques.
Two different types of thickness standards are realised. Metal film standards for X-ray techniques in the thickness range 10 to 50 nm are calibrated by GIXR with monochromatised synchrotron radiation of 8048 eV. The results obtained at four different facilities show excellent agreement. SiO2 on Si standards for SE and SFM in the thickness range 6 to 1000 nm are calibrated by GIXR with monochromatised synchrotron radiation of 1841 eV and with a metrological SFM. Consistent results within the combined uncertainties are obtained with the two methods. Surfaces and interfaces of both types of standards are additionally investigated by transmission electron microscopy (TEM).
Zinkschichten wurden mit den zerstörungsfreien Methoden Röntgenfluoreszenz (XRF), mechanischer Tastschnitt (MS), Röntgenbeugung (XRD) und instrumentierter Eindringprüfung (IIT) hinsichtlich der makroskopischen und mikroskopischen Schichteigenschaften untersucht. Die Rauheit der Zinkschichten hängt im Wesentlichen von der Substratoberfläche ab. Inhomogenen Schichtdickenverteilung treten bekanntermaßen am Rand von Beschichtungsgestellen auf. Die plasto-elastische Eigenschaften Härte, E-Modul und Kriechen sind bei unterschiedlichen Abscheidungen vergleich- und reproduzierbar. Diese makroskopischen Schichteigenschaften sind geprägt von der Mikrostruktur der Schicht, die eine Vorzugsorientierung der Kristallite in der Netzebene (110), die senkrecht zur Substratoberfläche steht, zeigt.
Haftvermögen, Topographie und optische Konstanten - zentrale Kenngrößen modifizierter Oberflächen
(2008)
Standardisation of ellipsometry is mainly based on three documents: pioneering work at NIST [1] on film standards, a publicly available specification and stan-dard testing procedure [2] for real-world samples by BAM and a standard specification for integrated metrology by SEMI [3]. Other activities refer to inter-laboratory comparisons for selected layer/substrate systems and analytical methods including ellipsometry [4] and the development of combined standards for thickness d and step height h [5].
Generally, precision of ellipsmetry in terms of raw data Ψ and Δ meets the major demands for all ellipsometric principles (RPE, RAE, PME, RCE, NE).
As a result, fingerprint capabilty is al-most perfect for various layer/substrate systems. However, this is not true for accuracy in terms of physical quantities such as thickness d, optical (n, k) and dielectric constans (ε1, ε2,) as modelling is required. Hence, the layer/substrate and material dependent validation of models is nowadays a key issue.
In contrast to the sub-nanometer sensi-tivity in vertical direction, the effective lateral resolution of almost all ellipso-metric principles except for imaging null
ellipsometry is rather poor, usually be-yond 100 µm.
Hence, nanometer-scaled homogeneity testing and the measurement of micro- and nanopatterned structures is not feasible by standard configurations.
Development of reference materials for surface technology in the micrometer and nanometer range
(2004)
Functionality of optical systems requires optical coatings of
high quality which have to be adapted to the application in
terms of the performance of optical parameters such as
reflectivity (AR, low, defined, high), the substrate material of
interest (polymers, ceramics, and glass), the environmental
conditions (such as temperature or humidity), and the service
conditions (such spectral range and power density). Moreover,
in many cases, additional non-optical requirements have
to be met, including mechanical features such as scratch
resistance, hardness and modulus.
Consequently, thickness and overall uniformity requirements
are steadily increasing. In general, these demands can usually
not be achieved by a single film or coating. Instead, films with
specific design features (such as gradients), layer stacks and
multilayers are a prerequisite for high quality layers and their
reliability. For the development of such layer systems, a
versatile cluster deposition system consisting of three clusters
and a cluster-to-cluster handler has been designed. Besides a
PECVD cluster for DLC coatings, two PVD clusters implement
ion assisted electron beam evaporation and plasmabased
sputter technology. In addition to metallic films, preparation
of oxide and nitride optical coatings (SiO2, TiO2, Ta2O5,
ITO, Al2O3, TiN, AlN) in various process modifications (nonreactive,
partially reactive, full-reactive; rf-, dc-, mf- mode;
PEM control) has been carried out.
Within this paper, the effect of several process parameters on
layer quality (optical constants, density, and uniformity) is
discussed for selected applications examples (AR- and HR
coatings, applications at elevated temperatures and applications
of enhanced mechanical performance).
It has been shown that specific features of ion and plasma
assisted PVD processes, including ion-beam and plasma preand
post-treatment of substrates and layer systems, may
widen the application range and improve functionality features
of given coating/substrate systems.
Entwicklung von Referenzmaterialien für die Oberflächentechnik im Mikrometer- und Nanometerbereich
(2004)
The synthesis of polymerlike amorphous carbon (a-C:H) thin-films by microwave excited collisional hydrocarbon plasma process is reported. Stable and highly aromatic a-C:H were obtained containing significant inclusions of poly(p-phenylene vinylene) (PPV). PPV confers universal optoelectronic properties to the synthesized material. That is a-C:H with tailor-made refractive index are capable of becoming absorption-free in visible (red)-near infrared wavelength range. Production of large aromatic hydrocarbon including phenyl clusters and/or particles is attributed to enhanced coagulation of elemental plasma species under collisional plasma conditions. Detailed structural and morphological changes that occur in a-C:H during the plasma synthesis are also described.
Dielectric, anti-reflective or high reflective systems consist of low and high refractive index layers. Common systems are oxides. The preparation of low refractive index MgF2-films of optical quality by means of an anhydrous low temperature solgel synthesis is presented. The MgF2-sol is prepared by spin-coating on silicon and glass substrates. Various film thicknesses between 20 nm and 435 nm have been deposited. It has been shown that the thickness increase is proportional to the number of coating steps. The deposited MgF2-films consist of 10 nm to 20 nm large nanoparticles and have smooth surfaces with an average roughness (Ra) of (1.7 ± 0.3) nm. The optical constants n and k of the films are in agreement with the literature data of bulk-MgF2.
Haftfestigkeit, Topographie und optische Konstanten - zentrale Kenngrößen modifizierter Oberflächen
(2008)
A gas sensor system based on the surface plasmon resonance (SPR) effect in a 44 nm Au layer was studied. The usability of this sensor system was investigated for several analyte gases and gas mixtures which are interesting due to their flammability, toxicity or greenhouse effect. The SPR effect of gold was measured in nitrogen and compared with the gaseous alkane series which caused a shift of the position of the SPR effect. For in situ measurements, the phase shift Δ at the SPR angle (ψ minimum) in the analyte gas mixtures was measured for investigated gases in comparison with nitrogen. With this method, detection limits of different gases could be determined, which lie in a range interesting for safety engineering. Furthermore the aging effect of the gold layers which leads to loss in sensitivity of the sensor was investigated.
A Round Robin (RR) exercise on selected coated materials has been carried out with the aim of finding the optimal conditions for the analysis of nitride layers with GD-OES. Such pre-normative work is necessary for the evaluation of parallel development of the production of nitride layers as certified reference materials (CRMs). Two types of samples, TiN layer and VN layer, respectively, with chemical compositions close to stoichiometry and a thickness of ~3 µm, deposited on a steel substrate, have been provided to the RR participants. Additionally, another type of sample, a (100 nm CrNi/100 nm Cu) multilayer (ML) stack deposited on silicon wafer has also been included in the RR. This sample can be used as a CRM for checking GD spectrometer conditions and it has been proved helpful in further development of GDS instrumentation and methodology. The RR exercise has been performed in the frame of the EC Thematic Network on Glow Discharge Spectroscopy for Spectrochemical Analysis (GDS-Net).