Institution
DECHEMA
Nonprofit•Frankfurt am Main, Germany•
About: DECHEMA is a nonprofit organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Corrosion & Oxide. The organization has 756 authors who have published 1307 publications receiving 25693 citations.
Papers published on a yearly basis
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TL;DR: In this paper, results from high temperature exposure tests performed on different Ti-alloys without any treatment and with a combination of Al-treatment plus fluorination are presented in the view of the use of the optimized Ti-components for several high temperature applications.
Abstract: High temperature Ti-alloys are usually sophisticated and hence expensive. To allow the use of cheaper alloys at elevated temperatures an economic and easy to apply procedure was developed to improve their high temperature capability. The treatment consists of a combination of Al-enrichment in a shallow surface region plus additional fluorination. The Al-enrichment at elevated temperatures leads to the formation of intermetallic TiAl-phases. These phases improve the oxidation resistance of Ti-alloys but not to a sufficient extent. An additional fluorine treatment of the Al-enriched surface leads to the formation of a protective alumina scale due to the fluorine effect. In this paper results from high temperature exposure tests performed on different Ti-alloys without any treatment and with a combination of Al-treatment plus fluorination are presented. The results are discussed in the view of the use of the optimized Ti-components for several high temperature applications.
2 citations
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01 Jan 19882 citations
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TL;DR: In this article, a repair method for technical enamels by using chemical nanotechnology was developed, based on liquid metal- alkoxides, a colloidal alumina sol and metal salts homogeneous sols with up to seven enamel compounds.
Abstract: The aim of the work presented here is the development of a novel repair method for technical enamels by using chemical nanotechnology. Good adhesion of coatings requires good wettability of the substrate by the repair solution. This was achieved by different pre-treatments of the steel substrates. Low sintering temperatures of the coatings can be ensured by the use of nanoparticle-based systems. Based on liquid metal- alkoxides, a colloidal alumina sol and metal salts homogeneous sols with up to seven enamel compounds were prepared. The sols were brush coated onto plain and partly enamelled steel substrates and sintered in a furnace, by inductive heating or an IR emitter. Thin (single layer << 1μm) crack-free layers were obtained on nearly all substrates independent of the sintering conditions investigated. The local sintering methods (IR emitter, inductive heating) allow to produce multiple coating systems in short times. Electrochemical impedance spectroscopy (EIS) provides evidence of the protective effect of these layers compared to the bare substrate, but as a result of their chemical composition the layers are not stable in the electrolytic environment for longer times. The thickness of such multiple coatings (20 layers, ≈8 μm) is still small compared to that of a technical enamel. Therefore, sol dispersion systems containing powder particles and sol components are applied on top of the sol-gel layers to increase the thickness of the sintered layers.
2 citations
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TL;DR: In this paper, a new approach of chromate-free surface pretreatment of aluminum alloy AA 1050 by using a modified phosphoric acid anodizing process, followed by an impregnation with a commercial SiO2-nanoparticle dispersion (Levasil® 300/30%) by dip-coating technique.
Abstract: The present work suggests a new approach of chromate-free surface pretreatment of aluminum alloy AA 1050 by using a modified phosphoric acid anodizing process, followed by an impregnation with a commercial SiO2-nanoparticle dispersion (Levasil® 300/30%) by dip-coating technique. The nanoparticles constitute an additional barrier layer against corrosion without closing the pores completely. The open porous oxide layer is a suitable promoter of adhesive bonding. The influence of withdrawing speed, the dipping time, solid content, temperature and pH-value in respect to the filling height in the pores of the anodized oxide layer were investigated. Surface morphology of the impregnated anodic oxide layers as well as their cross-section microstructure were investigated by scanning electron microscopy (SEM). Corrosion properties were investigated by electrochemical impedance spectroscopy (EIS) and adhesion was evaluated by single lap shear tests.
2 citations
Authors
Showing all 760 results
Name | H-index | Papers | Citations |
---|---|---|---|
Wolf B. Frommer | 105 | 345 | 30918 |
Michael W. Anderson | 101 | 808 | 63603 |
João Rocha | 93 | 1521 | 49472 |
Martin Muhler | 77 | 606 | 25850 |
Michael Hunger | 60 | 295 | 11370 |
Ivars Neretnieks | 44 | 224 | 7159 |
Michael Schütze | 40 | 343 | 6311 |
Jens Schrader | 38 | 129 | 4239 |
Roland Dittmeyer | 31 | 206 | 3762 |
Lei Li | 29 | 198 | 4003 |
Dirk Holtmann | 29 | 107 | 3033 |
Lasse Greiner | 26 | 74 | 1994 |
Klaus-Michael Mangold | 23 | 57 | 1590 |
A. Rahmel | 23 | 59 | 1967 |
Gerhard Kreysa | 22 | 78 | 1305 |