Process for manufacturing carbon fiber composite structures by membrane-assisted compression molding

The main objectives of this research work are to find new ways of reducing costs in the manufacture of composite materials, automate processes and improve energy efficiency by looking for alternatives to the use of autoclave, always meeting the quality requirements. For this, an out of autoclave curing process is studied through an innovative system of automatic and fast curing of composite parts for the aeronautic, automotive and construction sectors. The process allows the curing of prepregs of various materials and geometries. The process includes the provision of temperature by heating plate with electric resistances, pressure and vacuum adjustable through an air compressor, and cooling through circuit through mechanized plates. The main innovative feature of this system is the pressure supply with compressed air to the piece by means of a moldable and reusable silicone membrane, which allows to extend the field of study to complex elements saving the current limitation of hot plates presses, and without the need to place countermold. CFRP cured parts are manufactured in this new system, then their properties are compared with autoclave cured parts and similar properties are obtained, and auxiliary materials are considerably reduced. It can be concluded that this system improves energy efficiency, reduces costs and optimizes times

Industry 4.0: Materials and CFRP manufacturing process control through digital laboratory

Aerospace industry is well known to be one of the most demanding sectors to work with. It is strongly normalized, monitored and audited on behalf of airworthiness. In this scenario, continuous improvement is a must, to comply not only with requirements, but also lead times and costs. TITANIA, one of most recognized materials testing labs working for aerospace, moved to a tailor-made integral management system to deal with the high volume of data they deliver to their customers. After a two years effort, now is exploiting its results by offering better lead time compliances, robust test reports and new data analysis services. Digital transformation has pushed TITANIA into Industry 4.0. This paper presents the followed methodology and the first results obtained

Characterization of thermal protection elements for composites materials through thermal analysis

Highest level automotive competition is one of the sectors that takes the materials to the limit of their specifications in their commissioning, creating in this way knowledge in new technological fields. An example would be the use of structures made in CFRPs in competition, being gradually movin on the general automotive industry. The objective of this work is to determine the effectiveness of thermal protection elements that have to be installed in those structures of vehicles manufactured in CFRP exposed to high temperatures, such as pontoons covering the power unit and its exhaust manifolds, treating to discriminate which of them offer better protection at the lowest possible weight. In this work, 3 different protection systems have been evaluated, subjecting them to 3 types of tests, such as adhesion, weight and effectiveness of thermal protection. The method described here has made possible to evaluate the different efficacy of the systems tested, yielding additional data on the weight, adhesion and cost of the protection system

Characterization of new generations of out-of-autoclave prepregs (OoA)

New generations of out-of-autoclave prepregs, also known as VBP (vacuum bag only) are achieving a high maturity level that would allow the composite manufacturing with autoclave quality. These materials are characterized by its capability to allow air evacuation and minimize the presence of defects before its complete polymerization. To do this, it is necessary to control the factors which govern the phenomena that occur within it, such as compression, resin flow and void growth processes. Additionally, it should be considered fibers and resins properties, and curing cycle parameters such as temperature, vacuum quality and duration. In this work we have studied comparatively conventional and OoA prepregs.To do this, several panels have been laminated using hand lay-up method and cured only using vacuum bag and without autoclave pressure. Then, the panels have been characterized by optic microscopy, ultrasonic inspection and mechanical standarized tests. The results show that out-of-autoclave prepregs are achieving similar qualities to the conventional prepregs. Having completed this stage, new research and developments should be focused on, among other issues,  guaranteeing manufacturing processes robustness and optimization of bigger structures with complex geometries

Laser welding of AA 5083 samples by high power diode laser

Laser welding is a very attractive technique to join different alloys at the industrial level, due to Its low heat input, high flexibility, high weld quality and high production rate. In this work, the weldability of the aluminium alloy AA 5083 with a high power diode laser has been tested. Concisely, samples were subjected to lineal treatments of laser radiation, with the objective of studying the properties of the bead on plate welds generated. The main objective of the present work has been to study the influence of both the processing rate and the superficial treatment of the AA 5083 samples, on the morphological, microstructural and corrosion properties of the laser weld beads. The sizes of the welds were higher as the processing rate was decreased. The weld beads were seen to have better behaviour against corrosion than the base metal due to the microstructural refinement. It was also verified that a blasting process before processing gave beads with lower size but better corrosion resistance than the application of a black layer, due to the minimisation of the magnesium evaporation In this former superficial treatment. © 2008 Institute of Materials, Minerals and Mining.Peer Reviewe

Effect of the Environment on the Metal Release and Corrosion Behavior of Different Copper-based Alloys: Field Exposures at 5 Different Test Sites in Europe

reserved8paper 2192S. GOIDANICH; I. ODNEVALL WALLINDER; M.A. ARENAS; J. DE DAMBORENEA; M. ORMELLESE; J.M. SÁNCHEZ AMAYA; F.J. BOTANA; N. LE BOZECGoidanich, Sara; I., ODNEVALL WALLINDER; M. A., Arenas; J., DE DAMBORENEA; Ormellese, Marco; J. M., SÁNCHEZ AMAYA; F. J., Botana; N., LE BOZE

Biocorrosion of carbon steel alloys by an hydrogenotrophic sulfate-reducing bacterium Desulfovibrio capillatus isolated from a Mexican oil field separator

The hydrogenotrophic sulfate-reducing bacterium (SRB) Desulfovibrio capillatus (DSM14982(T)) was isolated from an oil field separator with serious corrosion problems; this is the study of its role in the corrosion of carbon steels under anaerobic conditions. Immersion tests with two steel alloys, St-35.8 (typical carbon steel employed in European naval industry), and API-5XL52 (weathering alloy steel employed in Mexican oil industries) were performed. Total exposure was 45 days and different concentrations of thiosulfate as electron acceptor for bacterial growth were employed. The samples immersed in media with SRB undergo fast activation and numerous active sites form on the surface. Microscopic observations were made by environmental scanning electron microscopy (ESEM). Weight loss and electrochemical testing included open circuit potential (E-corr), polarization resistance (R-p), electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) were measured with and without bacteria in the culture medium in order to determine corrosion rates and mechanisms. All electrochemical techniques have shown that after the end of the exponential phase the corrosion activity notably increased due to the high concentration of bacterial metabolites. Finally, the corrosion behavior of API-5XL52 was worse than St-35.8. (c) 2005 Elsevier Ltd. All rights reserved

Highly Sensitive Marker Panel for Guidance in Lung Cancer Rapid Diagnostic Units

Development and application of statistical models for medical scientific researc