ISBN 9783843909242

978-3-8439-0924-2, Reihe Technische Chemie

Patricia Lammel
Development and characterization of erosion-resistant metallic layers on composite materials

141 Seiten, Dissertation Universität Paderborn (2012), Hardcover, B5

Zusammenfassung / Abstract

The following dissertation mainly deals with the development of metallic coatings for fibre-reinforced polymers and their performance against solid particle and liquid impact. Nucleation and crystal growth of electrodeposited Cu onto carbon fibre-reinforced polymer (CFRP) surfaces were studied by means of in-situ atomic force microscopy (AFM) and complementary electrochemical techniques for the first time. Both the orientation of the composite fibres and the surface structure were changed to reveal the influence of these parameters on the nucleation and crystal growth. The modification of the surface was performed via an oxidative low temperature plasma process and the subsequent electrodeposition of Cu was accomplished from a 0.1 M CuSO4 solution at pH 2. It could be demonstrated that a plasma functionalized composite surface with carboxylic acid groups in combination with an induced change in surface topography strongly affects the nucleation and crystal growth of the deposited copper.

In addition, different electrodeposited Cr and Ni-based coatings on Cu-clad glass fibre-reinforced polymer (GFRP) as well as W bulk material were analysed with respect to their erosion behaviour. Rain erosion experiments were carried out using a pulsating jet erosion test rig (PJET) at a droplet velocity of 255 m/s and equivalent water droplets of 2 mm size. Sand erosion tests were performed by means of a TE 68 Gas Jet Erosion Rig at 55 m/s and 220 µm SiO2 particles. Different surface reactions and changes of the topography were determined after impact of water droplets and solid particles. It has been shown that liquid impact caused oxidation products such as NiO, WO2 and WO3 on Ni-W alloy coatings. Furthermore, brittle fracture or plastic deformation of the metallic coatings was obtained by the influence of erodents. In total, hardness and thickness of the metal layers were crucial properties for a considerable erosion resistance. The examined metal layers offered outstanding liquid impact and solid particle erosion resistance in contrast to the bare composite material.