Polycrystalline diamond films were synthesised on WC-Co hard metal tools by DC plasma-jet CVD. Fo... more Polycrystalline diamond films were synthesised on WC-Co hard metal tools by DC plasma-jet CVD. For machining abrasive Ž. materials the hard, wear resistant diamond films must be of good quality roughness, homogeneity, crystallinity, structure and show strong adhesion to the substrate. The wear behaviour of thin diamond films has been examined with abrasive particles in blast wear test and under ultrasonically-induced high frequency vibrations of a sonotrode in cavitation tests. The conditions of CVD diamond synthesis were varied with regards coating duration and process engineering. The influence of pre-treating the substrate surface for enhanced adhesion of the diamond film was also analysed. The microjets of the cavitation test react Ž. sensitively to coating defects considering the microstructure of the material. The failure mechanism adhesive, cohesive could be deduced from the worn surface. The blast wear test is less sensitive to coating microstructure, but the time of first coating failure as a quantitative wear criterion is helpful for improving the quality and adhesion of the diamond films. Thereby, the adaptation of synthesis conditions of diamond films is supported.
The WELLE research project aims to develop methodological and practical solutions for determining... more The WELLE research project aims to develop methodological and practical solutions for determining the overall water scarcity footprint of companies. Besides considering direct water consumption at production sites, WELLE’s approach also takes account of the local effects of indirect water use in upstream energy and material chains. The method development is performed by i) reviewing and evaluating existing methods for assessing water-related environmental impacts of organizations and ii) combining the existing product-related water footprint approach and the organizational life cycle assessment method. To make the method applicable in practice, guidelines for companies are developed. The applicability is ensured through a water inventory database, developed to satisfy the industry partners’ needs for regionalized water consumption data depicting their supply chain. An online tool for calculating a company’s water footprint according to the organizational water footprint method devel...
The scientific topic of LIPHASE is liquid-liquid phase separation in metals. One aim is to unders... more The scientific topic of LIPHASE is liquid-liquid phase separation in metals. One aim is to understand the development of a dispersion of liquid droplets. Thermophysical properties as surface tension, viscosity and especially the interface energy between the separating liquids are important parameters. LIPHASE establishes a link between theoretical and experimental investigations of the participating teams with focus on the use of microgravity platforms (sounding rockets, parabolic flights and the International Space Station ISS).
Complex aluminium bronzes (Cu-Al-Ni-Fe, Cu-Al-Mn-Fe-Ni alloy systems) are used for manufacturing ... more Complex aluminium bronzes (Cu-Al-Ni-Fe, Cu-Al-Mn-Fe-Ni alloy systems) are used for manufacturing prefabricated parts which must have a high resistance against wear and corrosion apart from high mechanical properties. Despite the favourable combination of mechanical properties and surface properties, the surface damages of these materials, which are caused by the use during operation, cannot be avoided. The extent of these damages determine the duration life of the workpieces. The high resistance of the alloys against wear and corrosion is only demanded by the surface. Therefore, it seems to be useful to fulfill the solicitation of the prefabricated parts by using a surface treated material. In the present paper, the surface melting was effected by means of a laser beam. The maximum value of the hardening turned out to be determined by the transformation behaviour of the alloy. The surface melting with laser beam partly optimised the corrosion properties and improved especially the c...
Messung von Ressourceneffizienz mit der ESSENZ-Methode, 2016
Interpretation der Ergebnisse Im Folgenden wird auf die Interpretation der in Kap. 5 berechneten ... more Interpretation der Ergebnisse Im Folgenden wird auf die Interpretation der in Kap. 5 berechneten Ergebnisse eingegangen. Dazu werden in einem ersten Schritt sowohl die Unsicherheiten der Gesamtmethode als auch der einzelnen Methodenbestandteile vorgestellt. Anschließend gibt es Hinweise für die Interpretation der betrachteten Kategorien und Dimensionen. Die Interpretation aller Kategorien für die Bewertung der Ressourceneffizienz des untersuchten Produktsystems ist wichtig, um Zielkonflikte innerhalb sowie zwischen den Dimensionen transparent aufzuzeigen und in die Handlungsempfehlung einfließen zu lassen. 6.1 Unsicherheiten in der Bewertung Im Folgenden wird auf die Unsicherheiten der ESSENZ-Methode eingegangen. Dieser Punkt ist für eine adäquate Interpretation der Ergebnisse von großer Bedeutung.
The influence of the deposition conditions on the properties of SiN x -coatings was investigated.... more The influence of the deposition conditions on the properties of SiN x -coatings was investigated. The characterized SiN x -coatings were deposited by the help of reactive magnetron sputtering. Gas pressure and film thickness were varied. Scanning electron microscopic views of the cross sections show a columnar structure varying with the deposition parameters. The different structures are comparable to the known structure zone models. There is a transition from dense structures to open columnar structures with increasing gas pressure. The Microstructure of coatings also changes with increasing film thickness. Especially deposition conditions promoting shadowing effects lead to a large growth of the column diameter with increasing thickness. The intrinsic stresses and the ultramicrohardness of the coatings change with changing gas pressure, too. Dense structures have high intrinsic stresses and a high hardness while coarse columnar structures have low intrinsic stresses and a low hardness. The influence of the deposition parameters on wear behaviour and adhesion of the SiN x -coatings was investigated by cavitation tests. Dense coatings with high intrinsic stresses show adhesion failures, and coatings with lower stresses and coarse columnar structures fail because of their lower intrinsic stability. Thus, there is an optimum gas pressure, at which the best properties are reached. It can be shown that with decreasing film thickness adhesion increases.
The following people have contributed by reviewing draft versions of the report and providing val... more The following people have contributed by reviewing draft versions of the report and providing valuable information and comments (Alphabetical
Kurzfassung Insbesondere im maritimen Sektor und in der chemischen Industrie, wo hohe Anforderung... more Kurzfassung Insbesondere im maritimen Sektor und in der chemischen Industrie, wo hohe Anforderungen an die Werkstoffe, hinsichtlich ihrer mechanisch-technologischen und Gebrauchseigenschaften gestellt werden, haben sich die Kupfer-Aluminium-Legierungen aufgrund der optimalen Verknüpfung der hervorragenden Korrosionsbeständigkeit in einer Vielzahl aggressiver Medien mit überdurchschnittlichen mechanischen und guten physikalischen Eigenschaften gut bewährt. Deshalb nehmen sie unter den Kupferwerkstoffen eine besondere Stellung ein.
Polycrystalline diamond films were synthesised on WC-Co hard metal tools by DC plasma-jet CVD. Fo... more Polycrystalline diamond films were synthesised on WC-Co hard metal tools by DC plasma-jet CVD. For machining abrasive Ž. materials the hard, wear resistant diamond films must be of good quality roughness, homogeneity, crystallinity, structure and show strong adhesion to the substrate. The wear behaviour of thin diamond films has been examined with abrasive particles in blast wear test and under ultrasonically-induced high frequency vibrations of a sonotrode in cavitation tests. The conditions of CVD diamond synthesis were varied with regards coating duration and process engineering. The influence of pre-treating the substrate surface for enhanced adhesion of the diamond film was also analysed. The microjets of the cavitation test react Ž. sensitively to coating defects considering the microstructure of the material. The failure mechanism adhesive, cohesive could be deduced from the worn surface. The blast wear test is less sensitive to coating microstructure, but the time of first coating failure as a quantitative wear criterion is helpful for improving the quality and adhesion of the diamond films. Thereby, the adaptation of synthesis conditions of diamond films is supported.
The WELLE research project aims to develop methodological and practical solutions for determining... more The WELLE research project aims to develop methodological and practical solutions for determining the overall water scarcity footprint of companies. Besides considering direct water consumption at production sites, WELLE’s approach also takes account of the local effects of indirect water use in upstream energy and material chains. The method development is performed by i) reviewing and evaluating existing methods for assessing water-related environmental impacts of organizations and ii) combining the existing product-related water footprint approach and the organizational life cycle assessment method. To make the method applicable in practice, guidelines for companies are developed. The applicability is ensured through a water inventory database, developed to satisfy the industry partners’ needs for regionalized water consumption data depicting their supply chain. An online tool for calculating a company’s water footprint according to the organizational water footprint method devel...
The scientific topic of LIPHASE is liquid-liquid phase separation in metals. One aim is to unders... more The scientific topic of LIPHASE is liquid-liquid phase separation in metals. One aim is to understand the development of a dispersion of liquid droplets. Thermophysical properties as surface tension, viscosity and especially the interface energy between the separating liquids are important parameters. LIPHASE establishes a link between theoretical and experimental investigations of the participating teams with focus on the use of microgravity platforms (sounding rockets, parabolic flights and the International Space Station ISS).
Complex aluminium bronzes (Cu-Al-Ni-Fe, Cu-Al-Mn-Fe-Ni alloy systems) are used for manufacturing ... more Complex aluminium bronzes (Cu-Al-Ni-Fe, Cu-Al-Mn-Fe-Ni alloy systems) are used for manufacturing prefabricated parts which must have a high resistance against wear and corrosion apart from high mechanical properties. Despite the favourable combination of mechanical properties and surface properties, the surface damages of these materials, which are caused by the use during operation, cannot be avoided. The extent of these damages determine the duration life of the workpieces. The high resistance of the alloys against wear and corrosion is only demanded by the surface. Therefore, it seems to be useful to fulfill the solicitation of the prefabricated parts by using a surface treated material. In the present paper, the surface melting was effected by means of a laser beam. The maximum value of the hardening turned out to be determined by the transformation behaviour of the alloy. The surface melting with laser beam partly optimised the corrosion properties and improved especially the c...
Messung von Ressourceneffizienz mit der ESSENZ-Methode, 2016
Interpretation der Ergebnisse Im Folgenden wird auf die Interpretation der in Kap. 5 berechneten ... more Interpretation der Ergebnisse Im Folgenden wird auf die Interpretation der in Kap. 5 berechneten Ergebnisse eingegangen. Dazu werden in einem ersten Schritt sowohl die Unsicherheiten der Gesamtmethode als auch der einzelnen Methodenbestandteile vorgestellt. Anschließend gibt es Hinweise für die Interpretation der betrachteten Kategorien und Dimensionen. Die Interpretation aller Kategorien für die Bewertung der Ressourceneffizienz des untersuchten Produktsystems ist wichtig, um Zielkonflikte innerhalb sowie zwischen den Dimensionen transparent aufzuzeigen und in die Handlungsempfehlung einfließen zu lassen. 6.1 Unsicherheiten in der Bewertung Im Folgenden wird auf die Unsicherheiten der ESSENZ-Methode eingegangen. Dieser Punkt ist für eine adäquate Interpretation der Ergebnisse von großer Bedeutung.
The influence of the deposition conditions on the properties of SiN x -coatings was investigated.... more The influence of the deposition conditions on the properties of SiN x -coatings was investigated. The characterized SiN x -coatings were deposited by the help of reactive magnetron sputtering. Gas pressure and film thickness were varied. Scanning electron microscopic views of the cross sections show a columnar structure varying with the deposition parameters. The different structures are comparable to the known structure zone models. There is a transition from dense structures to open columnar structures with increasing gas pressure. The Microstructure of coatings also changes with increasing film thickness. Especially deposition conditions promoting shadowing effects lead to a large growth of the column diameter with increasing thickness. The intrinsic stresses and the ultramicrohardness of the coatings change with changing gas pressure, too. Dense structures have high intrinsic stresses and a high hardness while coarse columnar structures have low intrinsic stresses and a low hardness. The influence of the deposition parameters on wear behaviour and adhesion of the SiN x -coatings was investigated by cavitation tests. Dense coatings with high intrinsic stresses show adhesion failures, and coatings with lower stresses and coarse columnar structures fail because of their lower intrinsic stability. Thus, there is an optimum gas pressure, at which the best properties are reached. It can be shown that with decreasing film thickness adhesion increases.
The following people have contributed by reviewing draft versions of the report and providing val... more The following people have contributed by reviewing draft versions of the report and providing valuable information and comments (Alphabetical
Kurzfassung Insbesondere im maritimen Sektor und in der chemischen Industrie, wo hohe Anforderung... more Kurzfassung Insbesondere im maritimen Sektor und in der chemischen Industrie, wo hohe Anforderungen an die Werkstoffe, hinsichtlich ihrer mechanisch-technologischen und Gebrauchseigenschaften gestellt werden, haben sich die Kupfer-Aluminium-Legierungen aufgrund der optimalen Verknüpfung der hervorragenden Korrosionsbeständigkeit in einer Vielzahl aggressiver Medien mit überdurchschnittlichen mechanischen und guten physikalischen Eigenschaften gut bewährt. Deshalb nehmen sie unter den Kupferwerkstoffen eine besondere Stellung ein.
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