bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of the Damping Characteristics of Fiber-Metal-Elastomer Laminates Using Piezo-Indicated-Loss-Factor Experiments
Authors: Sessner Vincent , Stoll Matthias , Feuvrier Arnaud , Weidenmann Kay André
Published: July 2017

. In technical applications components are often exposed to vibrations with a broad range of frequencies. To ensure structural integrity and a convenient usage for the customer, materials with good damping characteristics are desirable. Especially stiff and lightweight structures tend to be prone to vibrations. Fibre metal laminates (FML) offer great potential for lightweight design applications due to their good fatigue behavior. By using carbon fiber reinforced plastics (CFRP) as part of the laminates very good strength and stiffness to weight ratios can be obtained. To improve the damping characteristics of this hybrid material an additional layer of elastomer can be added between the CFRP and the metal, generating a fiber-metal-elastomer laminate (FMEL). In this present study the damping behavior of different layups of FMEL was examined. Two different metal sheets and two types of elastomer were used, also the layup of the constituents was variated. Vibrations were induced with a frequency range from 100 Hz to 20 kHz by mounting the laminates onto a speaker. The vibration response was measured with a piezoelectric accelerometer. Eventually the different laminate layups were compared with each other to determine the influence of the individual constituents regarding the damping characteristics. The different elastomer types and prepreg layups affected the damping of vibrations, whereas the use of different metal sheet materials showed only little influence.
Damascus Steel Inlay on a Sword Blade - Production and Characterization
Authors: Strobl Susanne , Haubner Roland , Scheiblechner Wolfgang
Published: July 2017

Using the Damascus technique and forging steel plates with different carbon concentrations results in a composite material with a layered structure and combines the properties of the individual materials. Detailed investigations on old Sax swords from the 8th century indicate that Damascus steels were also used for decoration by applying the inlay technique. For the replication of a Sax sword a steel blade was manufactured and the Damascus steel inlay was upset by forging. From a test sample a cross section was investigated by means of metallographic methods. Of high interest are the intersections between the Damascus steel inlay and the core of the blade. After metallographic preparation the various microstructures were characterized by light optical microscopy and Vicker ́s microhardness measurements were performed.
Ultrasonic Torsion Welding of Aging Resistant Al/CFRP Joints - Concepts, Mechanical and Microstructural Properties
Authors: Staab Florian , Balle Frank , Born Johannes
Published: July 2017

Multi-material-design offers high potential for weight saving and optimization of engineering structures but inherits challenges as well, especially robust joining methods and long-term properties of hybrid structures. The application of joining techniques like ultrasonic welding allows a very efficient design of multi-material-components to enable further use of material specific advantages and are superior concerning mechanical properties.The Institute of Materials Science and Engineering of the University of Kaiserslautern (WKK) has a long-time experience on ultrasonic welding of dissimilar materials, for example different kinds of CFRP, light metals, steels or even glasses and ceramics. The mechanical properties are mostly optimized by using ideal process parameters, determined through statistical test planning methods.This gained knowledge is now to be transferred to application in aviation industry in cooperation with CTC GmbH and Airbus Operations GmbH. Therefore aircraft-related materials are joined by ultrasonic welding. The applied process parameters are recorded and analyzed in detail to be interlinked with the resulting mechanical properties of the hybrid joints. Aircraft derived multi-material demonstrators will be designed, manufactured and characterized with respect to their monotonic and fatigue properties as well as their resistance to aging.
Aspects of Preloaded Bolted Joints of Fiber Reinforced Polymers and Metals
Authors: Hausmann Joachim M. , Helfrich Bernhard , Motsch Nicole
Published: July 2017

To join components of fiber reinforced polymers (FRP) to metals or FRP, too, bolted joints are used regularly. Reliability, affordability, and disassembly are the drivers for dissemination of this joining technique; despite some disadvantages. For bolted joints of metals it is well known, that a preloading of the bolts increases the efficiency drastically. Therefore, preloaded screws are the standard in mechanical engineering. Prerequisite is a load transfer by friction of the joining partners induced by a preload of the bolt. However, when joining FRP components a preloading of the bolts is usually not considered since a force release is afraid due to creeping of the polymeric matrix. Furthermore, the load transfer by friction of FRP is not investigated sufficiently. The limiting parameters of preloaded bolted joints of different FRP materials are investigated here. Particularly these are the allowed contact pressure at the bolt heads or washers, the coefficient of friction in the joining zone, and the release behavior of the preloading. The load transfer capability of bolted joints under optimized conditions is presented.
Deposition of CVD Diamond Coatings on Carbon Fiber Composite Substrates
Authors: Haubner Roland , Lessiak Mario
Published: July 2017

Boron doped diamond coatings are used in electrochemistry, due to the high overvoltage for oxygen generation. Niobium is often used as bulk material, but also diamond deposition on titanium was demonstrated. For metallic bulk materials corrosion can take place in case of defects in the diamond coating. This problem can be avoided by using carbon based substrates. Diamond deposition on carbon substrates is difficult, because atomic Hydrogen needed for diamond growth attacks graphitic and amorphous carbon. These reactions have the effects that carbon in the substrate is etched and the amount of atomic hydrogen needed for diamond growth is reduced. To reduce the carbon etching on the substrate, the duration till diamond layer formation should be short. By controlling the diamond deposition conditions, boron addition and seeding with diamond prior to deposition, the formation of diamond coatings on carbon fibre composites (CFC) is possible. Electrochemical measurements of the boron doped diamond coatings verified the excellent electrochemical properties of the samples, e.g. good electrical conductivity, high overvoltage for oxygen and hydrogen but also chemical inertness.
Formulation and Manufacturing of Polybenzoxazine Composites
Authors: Werner Jonas , Schäfer Hannes , Faßbender Fabian Julius , Koschek Katharina
Published: July 2017

Polybenzoxazines offer excellent properties regarding mechanical performance, chemical stability, good flame resistance and low water absorption. High curing temperatures of benzoxazine monomers, however, impede the processing of composites. Therefore, this contribution presents a formulation of polybenzoxazines with the aim to reduce the curing temperature and facilitate Out of Autoclave (OoA) oven processes. This is accomplished by copolymerizing benzoxazine monomers with a poly(ε-caprolactone) based plasticizer yielding a resin exhibiting viscosities and reduced curing temperatures suitable for a vacuum infusion as well as compression process. Air void free composites were manufactured successfully featuring temperature dependent mechanical behavior.
3rd Generation Hot-Dip Galvanized Steel Sheet for Automobile Manufacturing - Interface Reactions between Zinc and Metal Oxide
Authors: Maderthaner Magdalena , Jarosik Alexander , Angeli Gerhard , Haubner Roland
Published: July 2017

There is a growing demand for Advanced High Strength Steels (AHSS) in the automotive industry owing to their high specific strength and good formability. The mechanical properties satisfy the demands for improved passenger safety and decreased vehicle weight due to thinner cross sections. Hot-dip galvanizing is a common procedure to prevent corrosion of steel, galvanized steel forms the basis for further processing like organic coating. Industrially, the steel strip is annealed at 840 °C in 5 % H2 in N2 at a dew point (DP) of -30 °C. These conditions are reducing for Fe, but oxidizing for oxygen-affine alloying elements as Mn, Si and Cr. These ignoble elements form an external, covering oxide layer on the steel surface, which exhibits poor wettability for the Zn(Al, Fe)-bath. The liquid Zn(Al, Fe) has a temperature of 460 °C and contains 0,2 wt% Al to form a Fe2Al5-xZnx-layer to inhibit the growth of Fe-Zn-intermetallics. Along with the increased amount of alloying elements to improve strength and ductility of AHSS the evolving oxide layer after annealing at the steel surface deteriorates hot-dip galvanizing. The question arises what happens to the surface oxides during immersion in the Zn(Fe, Al)-bath. For this purpose annealed as well as annealed and galvanized 0.8Si-AHSS and 1.5Si-AHSS were compared by glow discharge optical emission spectroscopy (GD-OES) depth profiles. Galvanized specimens show fewer oxides at the steel-zinc-interface as annealed specimens. A possible explanation is an aluminothermic reduction of oxides by 0.2 wt% dissolved Al in the Zn(Al, Fe)-bath. Al is thermodynamically more affine to oxygen than Mn and Si and may reduce Mn- and Si-oxides. An alternative theory is the dissolution of Fe in Zn during reactive wetting, as a side effect the oxides are rinsed off too. Additionally, the influence of DP was investigated. According to Wagner’s theory of selective oxidation, a higher amount of oxygen in the annealing atmosphere leads to internal oxidation of the alloying elements. Experiments were carried out with 0.8Si-AHSS and 1.5Si-AHSS by altering the DP during annealing from -30 °C (380 ppm H2O) to 0 °C (6000 ppm H2O). Oxidation mode changed from external (DP -30 °C) to internal oxidation along grain boundaries (DP 0 °C), as predicted by Wagner. These oxide-free surface provides good reactivity to enhance reactive wetting with the Zn(Fe, Al)-bath and form a dense Fe2Al5-xZnx-layer.
HybridRTM - Quality Controlled Manufacturing of Hybrid Material Composites through Resin Transfer Moulding
Authors: Fauster Ewald , Hergan Patrick , Stelzer Steffen , Scheiblhofer Stefan , Cespedes-Gonzales Gilbert , Pfeifer Susanne , Rittenschober Bernhard , Sieberer Manfred , Lauermann Michael , Schledjewski Ralf
Published: July 2017

HybridRTM terms a publicly funded project, which aims at the development of a processing technique for manufacturing of light weight structural components from hybrid materials. In particular, components involving metal as well as fibre-reinforced polymer composite materials are manufactured in a single processing step by means of the resin transfer moulding (RTM) technique. Project activities include material development and characterization, modelling of thermally induced residual stresses, process simulation, mould development as well as model-based process control in order to ensure consistently high component quality. This paper outlines the fundamental idea of the project and summarizes the most important results gained during the first two years of project activities.
Separation of Hybrid Structures for the Reclaim of their Single Components
Authors: Schweizer Swetlana , Becker-Staines Anna , Tröster Thomas
Published: July 2017

The main objective for an economic and ecological use of raw materials is the achievement of closed raw material cycles. Because of that, not only the manufacturing procedures are important during the development of new materials but also the recycling processes. Within the increased use of lightweight construction in recent years, the application of multi-material or hybrid structures reach high significance for the automotive industry. In this development, especially the carbon fibre reinforced plastics (CFRP) gained its importance. However, currently there are no recycling strategies available for hybrid structures; complete recycling processes for CFRP are still expandable. This work presents methods for separation of hybrid structures made of metal and CFRP, as well as the corresponding process windows and the boundary conditions. The separation is performed by introduction of thermal heat and the behaviour of these bonded compounds is analyzed based on shear tensile tests. The results of these studies are used to develop a complete recycling process for reclamation of hybrid structures.
Surface Modification of Recycled Carbon Fibers by Use of Plasma Treatment
Authors: Schneller Anna , Mueller Wolfgang M. , Roessle Ramona , Horn Siegfried R.
Published: July 2017

In this study, sized and thermally desized virgin carbon fibers (vCF) as well as recycled carbon fibers (rCF) from a thermal recycling process are plasma treated by a plasma-jet. The effect of two different process gases (nitrogen and dinitrogen monoxide) and the influence of the distance between the plasma source and the fiber surface are studied with the aim of increasing the oxygen and nitrogen concentration on the rCF surfaces. Higher surface coverage of oxygen-and nitrogen-containing functional groups is supposed to lead to a better adhesion between the carbon fiber and the epoxy resin matrix. The elemental compositions and functional groups of the treated carbon fiber surfaces are studied by x-ray photoelectron spectroscopy. The effect of plasma treatment on the fiber properties like tensile strength, tensile modulus and surface roughness is investigated.
A Holistic Approach to Use Multi-Scale Fractions of Dry Carbon Fibre Production Waste in Filled Bulk Moulding Compounds (BMC)
Authors: Huether Jonas , Maertens Robert , Saburow Oleg , Seiler Elisa , Aicher Theresa , Weidenmann Kay André
Published: July 2017

The increasing demand for composites leads to a growing amount of end-of-life materialand production waste. The latter consists of a large fraction of unimpregnated fibre waste which is notsufficiently reprocessed using conventional textile processing procedures as they are either too expensiveor their mechanical performance is too low. Using pieces of dry non-crimp fabrics (patches) ina Bulk Moulding Compound process (BMC) displays a straightforward approach of fabric recycling.Adding fillers to the mixture not only offers the opportunity to modify mechanical and electrical propertiesas well as the costs but also a chance for a more holistic approach of dry fibre recycling, whenconventional fillers like chalk are replaced by ground recycled carbon fibres. In this way, all kindof dry fibre wastes can be reused in one process: Larger offcuts are chopped to smaller rectangularpatches whereas waste fractions of small offcuts are processed to carbon fibre powder as filler andprocessed together with resin to produce BMC materials. Mechanical investigations reveal that thepresented approach shows higher specific properties than the conventional filler without compromisingthe process and material quality.
Measurements of Mode I Interlaminar Properties of Carbon Fiber Reinforced Polymers Using Digital Image Correlation
Authors: Merzkirch Matthias , Ahure Powell Louise , Foecke Tim
Published: July 2017

Numerical models based on cohesive zones are usually used to model and simulate the mechanical behavior of laminated carbon fiber reinforced polymers (CFRP) in automotive and aerospace applications and require different interlaminar properties. The current work focuses on determining the interlaminar fracture toughness (GIC) under Mode I loading of a double cantilever beam (DCB) specimen of unidirectional CFRP, serving as prototypical material. The novelty of this investigation is the improvement of the testing methodology by introducing digital image correlation (DIC) as an extensometer and this tool allows for crack growth measurement, phenomenological visualization and quantification of various material responses to Mode I loading. Multiple methodologies from different international standards and other common techniques are compared for the determination of the evolution of GIC as crack resistance curves (R-curves). The primarily metrological sources of uncertainty, in contrast to material specific related uncertainties, are discussed through a simple sensitivity analysis. Additionally, the current work offers a detailed insight into the constraints and assumptions to allow exploration of different methods for the determination of material properties using the DIC measured data. The main aim is an improvement of the measurement technique and an increase in the reliability of measured data during static testing, in advance of future rate dependent testing for crashworthiness simulations.
Surface Pretreatment of Fiber-Reinforced Plastics via VUV Radiation
Authors: Schmüser Christoph , Rosanova Kira , Dölle Christopher
Published: July 2017

Fiber-reinforced plastics (FRP) are of great importance for the transport sector, the aerospace industry, for wind power plants, in the building sector and in the field of sports and leisure applications. Optimization of the adhesive bonding process for FRP structures, especially the surface preparation prior to bonding, will be of a central importance in forthcoming expansion of FRP use. In this connection the key problem depends on the FRP polymer matrix. In the case of duroplastic matrix the main problem is the presence of release agent on the surface of joining components. For the thermoplastic matrix such as polypropylene (PP), the main problems are the low surface energy and the inertness of its surface. Conventional pretreatment methods, such as manual grinding, shall be replaced by energetic radiation technics like VUV lamps (vacuum ultraviolet spectral range: 100 – 200 nm). This approach is a non-contact method, characterized by high treatment homogeneity and material-saving properties, combined with no further fibers to be released. The surface of the thermoplastics is activated by the incorporation of oxygen, release agent contamination on the thermoset is cleaned or modified [1 - 8]. The results of the VUV surface activation of PP and CFRP with regard to the incorporation of functional groups, increase of surface energy, matrix degradation and the adhesion increase of adhesive bonds are presented. In addition, studies on the release agent coating and the release agent modification by VUV radiation are presented. The work is completed by considerations concerning possibilities to accelerate the process (in particular, wavelength dependence, influence of an inert gas or the moisture content). Finally, an evaluation of the VUV pretreatment is carried out on the basis of two specific applications.
An Integrated Virtual Tool Chain for the Simulation of the Manufacturing Process of a Composite Tidal Blade
Authors: Brauner Christian , Pascon Frédéric , van Eekelen Tom , Bach Maarten , Kolovaar Arjen , Breede Arne
Published: July 2017

Within the European research project ECOMISE advanced process simulation methods have been developed. Existing Software tools like RTMWorx and NX CAE have been extended in their capabilities and interface have been developed between them to have a direct data communication. In the present case a manufacturing process of a tidal blade was used to test and validate the development. In RTMWorx a new 3D solution was developed and an a import interface to read direct a structural model from NX with all related information’s like geometry, mesh and layup. The interface reads the ply information’s and calculates resulting permabilities for the layup. In NX CAE also interfaces and mapping algorithm have been developed to read information’s like filling factors from RTMWorx. In combination with the new functionalities to simulate curing, process induced deformation and residual stresses the virtual process chain enabling a complete analysis of the whole manufacturing process starting from a initial design with capabilities on draping including direct ply contour creation, infusion, curing and analysis of process induced deformation.
Numerical Analysis on the Structural Behavior of a Non-Engaging CFRP Bellows Coupling for Propulsion Technology
Authors: Oblinger Christian , Baeten André , Drechsler Klaus
Published: July 2017

Fiber reinforced polymers (FRP) are used in a widespread range, for example in aerospace, mobility or wind energy applications due to their excellent quality profile. Moreover, rotating machine elements, which are applied in dynamic processes, require a primarily high stiffness combined with an elastic behavior. Novel FRP components or modern hybrid structures lead to a lower energy consumption of the entire mechanical system. In this respect, a shaft coupling between two shafts depicts an exemplary machine element for a possible application of FRP. This paper deals with the numerical analysis on the structural behavior of a non-engaging bellows coupling made of prepreg-based carbon fiber reinforced polymers (CFRP) for propulsion technology. The presented concept is based on the methodological construction approach for the fulfillment of the compensation and connection functionality. A very high torsional stiffness as well as a certain bending flexibility of the whole coupling geometry is required due to the connection of two torsion-loaded structures. Specific geometrical design variables could be identified with the finite elements method (FEM) and the design of experiments (DoE), which have a significant influence on the structure mechanical behavior of the CFRP bellows coupling. Based on a variable identification scheme according to Shainin, the influence of various geometrical design factors on the structural performance of the CFRP bellows coupling was evaluated.
An Approach for the Systematic Development of Progressive Light Weight Spring Element Concepts in Vehicle Constructions
Authors: Knorre Michael , Brandt Robert
Published: July 2017

Commercial vehicles are mostly equipped with pneumatic spring elements which lead to a perfect height levelling and spring rate adjustment under different loading conditions. However, pneumatic springs are not common in light commercial vehicles where passive spring elements, e.g. single- and multi-leaf springs, are still be used. Since those vehicles are covering a wide range of different loads the spring elements frequently exhibit a progressive spring characteristic, i.e. the spring rate is adjusted under deflection as soon as the load is increased. The need for light weight design also relates to light commercial vehicle so that glass fibre reinforced plastic (GFRP) has become a suitable substitute for high strength steel. Furthermore GFRP allows for innovative as well as functionally and technologically improved constructional solutions of progressive spring elements, e.g. the single-leaf spring approach by Schürmann et al [1].However, the above mentioned solution is sometimes rather solitaire and no systematic approach for its genesis exits. Hence, this contribution shows an approach for a more systematic development of progressive light weight spring element concepts in vehicle construction. Different approaches of implementing a progressive spring rate characteristic are presented in the introduction. A simple analytical model of a bending beam considering a variety of boundary conditions has been set up to discuss the effect of bearing stiffness on the spring rate.The model serves as a basis for a kind of toolbox for a more systematic approach for the development of the desired progressive spring elements. It allows to identify and to select a balanced concept for a progressive light weight spring element which also considers the application of the appropriate spring material at any specific part of the construction.
Light Weight Vehicle in Natural Fibre Composite
Authors: Wüstenhagen Sven , Krombholz Andreas , Theumer Torsten , Funke Patrick , Lange Olaf
Published: July 2017

Combined with shared service points in prime locations the use of Light Electric Vehicles (LEV) can help optimize the cost expensive „last mile“ of parcel service. [1] At the same time, a shared service point enables the switch from diesel driven engines to muscle-powered electric driving in cities. It is known, that in city operating courier services up to 80 % of actual used diesel fuel can be substituted by muscle supported electric driving. [2] To cover the needs of global operating parcel services a muscle-power supported LEV must meet the requirements of ergonomics (regarding usability in the modes drive and delivery) and parcel security. To gain economic benefits the construction of LEV for parcel delivery should be flexible enough to meet specific needs in cities - like the topography of the roadways, daily amount of goods to deliver and the legal provision at the local situation. Production of LEV in small and medium enterprises will unlock a niche for first industrial uses of Natural Fiber Composites (NFC) in load-bearing structures. By pre-impregnation a replicable quality will bring the structural light-weight construction with NFC to new fields of use, as the construction of a LEV will demonstrate. At the end of its life cycle, the vehicle proves further economic and ecological benefits due to the use of NFC: A cost effective thermal conversion under a reduced release of fossil CO2 is guaranteed. [3; 4]
Electro-Mechanical Impedance Measurements as a Possible SHM Method for Sandwich Debonding Detection
Authors: Kralovec Christoph , Schagerl Martin
Published: July 2017

The present article addresses the evaluation of the electro-mechanical (E/M) impedance method as a Structure Health Monitoring (SHM) method to detect and classify damage, more specific, the debonding of a face layer.In the study the considered structure is simplified as a circular sandwich panel of constant thickness, consisting of isotropic face layers and a honeycomb core.The debonding is assumed to be circular and situated at the center of the panel, only variable in its radius.The article starts with a brief introduction to the basic idea of SHM and the fundamentals of the E/M impedance method.Further, the idealized setting is investigated by two sets of experiments whose results are analyzed by typically used damage metrics and by considering both analytical and numerical models.A coupled-field FEM model is developed and compared to the experimental results.Furthermore, an analytical model is derived to evaluate the experimental and numerical results.All results are presented and discussed extensively on pursuing the objective to detect and classify the size of a debonding.Finally, it is shown how a model based approach can predict the presence but also the size of a debonding in the considered sandwich panels based on the E/M impedance measurements.
Experimental Investigations on Integrated Conductor Paths in Fiber-Reinforced Thermoplastic Composite Structures
Authors: Weber Tony , Winkler Anja , Gude Maik
Published: July 2017

By the benefit of functional integration the advantages of fiber reinforced plastics (FRP) as construction material can be increased due to the possibilities of integrating sensors and actuators. In Regard to the layer-by-layer definition of the wall thickness, this class of material offers a high potential for the integration of additional smart elements within the stacking and forming process. In addition to the actual integration methods of sensors or actuators, the electrical signal transmission and contacting is of great importance for smart structures. Various approaches can be followed. On the one hand, the conductor path can be defined by means of a wire and, on the other hand, the definition of conductor paths can be accomplished by functionalized films (by means of printing technology). Within this paper, experimental investigations are intended to demonstrate the suitability of screen-printed conductor paths for the press-technical transformation of FRP structures. In addition to the variation of the screen printing material and the film material, for a material-homogeneous integration, an evaluation of a corresponding selection of materials takes place with respect to the stresses derived from the deformation-technical boundary conditions.
In-Process Monitoring of Joining Operations for Piezoceramic Elements
Authors: Müller Benedikt , Pierer Alexander , Schmidt Marek , Schubert Andreas , Koriath Hans Joachim , Putz Matthias , Wittstock Volker
Published: July 2017

The direct integration of piezo elements into micro-structured aluminum sheets is a new approach for adaptronics and lightweight constructions. With the integration of the active piezoceramic elements the aluminum sheets gain sensor and actuator functionalities. The mechanical interconnections and the preload of the piezoceramic elements are an important issue for the sensor and actuator capability of the later smart material. Post-process inspection methods to characterize the mechanical interconnection of the joining partners and the performance of the transducer after the joining operation are state of the art. Scope of the paper is the development of a novel in-process monitoring method that utilizes the piezoceramic transducer as inherent sensor for failure mode detection and preload evaluation during the joining by forming operation. Within this study, results of forming experiments with array batches of interconnected piezoceramic elements are presented. The piezoceramic batches are electrically contacted inside the joining tool and utilized as material inherent sensor during joining by forming experiments. Test samples are characterized by impedance spectroscopy during the joining operation. Based on the experimental results, a novel in-process-monitoring method utilizing the piezoceramic joining partners as inherent sensor is outlined. It is shown, that with this method a sufficient preload can be adjust on the basis of the intensity of the resonance peak without an overload. Furthermore, error effects to the transducer can be detected at an early stage.
Quality Controlled UD Tape Production for the Individualised Production of Load Optimised Thermoplastic Composite Parts
Authors: Hopmann Christian , Beste Christian , Hildebrandt Markus , Boettcher Arne , Fischer Kai
Published: July 2017

A flexible and individual component manufacturing process for thermoplastic composites (TPC) has been developed at the Institut fuer Kunststoffverarbeitung in Industrie und Handwerk an der RWTH Aachen (Institute of Plastics Processing (IKV) at RWTH Aachen University). The process consists of a quality controlled tape production and a combined forming and joining process with additive manufactured functional structures. This paper describes the requirements for the unidirectional (UD) tape properties and the quality controlled tape production line in order to allow for a flexible and individual component manufacturing of load optimised thermoplastic composite parts. Besides the UD tape geometry and fibre impregnation quality an even fibre distribution over the width of the UD tape is an important characteristic. Results of investigations regarding the online measured quality data (fibre distribution) and offline measured UD tape properties (local fibre weight content) are presented and discussed.
Adaptation of TiC Hard Particles Properties and Morphology in Metal Matrix Composites by Refractory Elements
Authors: Mohr Andreas , Röttger Arne , Theisen Werner
Published: July 2017

High mechanical loads, corrosion, and abrasion decrease the lifetime of tools. One way to increase the wear resistance of tool materials can be achieved by adding hard particles to the metal matrix such as titanium carbide, which protect the softer metal matrix against abrasive particles. This material concept is designated as metal matrix composite (MMC). Ferro-Titanit® is such MMC material, possessing high wear and a simultaneously high corrosion resistance, for which reason this material is used in the polymers industry. The material concept is based on a corrosion-resistant Fe-base matrix with up to 45 vol% titanium carbide (TiC) as a hard particle addition to improve the wear resistance against abrasion. These TiC hard particles must be adapted to the present tribological system in terms of hardness, size and morphology. This study shows how the size and morphology of TiC hard particles can be influenced by the refractory element niobium (Nb). Therefore, the element Nb was added with 2 and 4 mass% to the soft-martensitic Ferro-Titanit® Grade Nikro128. The investigated materials were compacted by sintering, and the densified microstructure was further characterized by scanning electron microscopy (SEM), energy dispersive spectrometry (EDX), and optical image analyses. Furthermore, microstructure and properties of the compacted Nb-alloyed samples were compared to the reference material Nikro128. The results show that the addition of Nb influences the morphology, size and chemical composition of the TiC hard particle. These changes in the hard phase characteristics also influence the materials properties. It was shown that the phase niobium carbide (NbC) is formed around the TiC during the densification process, leading to a change in morphology and size of the TiC.
Experimental Study of Charge Motion in a Tumbling Ball Mill
Authors: Machado Marcela Vieira Caixeta , Straatmann V. , Duarte Claudio Roberto , Barrozo Marcos A.S.
Published: July 2017

Tumbling ball mills are a common comminution device in the mineral industry processing, wherein the particle size reduction is performed by action of the grinding media. Different forms of transverse motion in a rotating cylinder have been studied by many researchers. The aim of this paper was to study the transitional phenomena between cascading, cataracting and centrifuging motion. In order to observe these transitions, experiments were carried out in a tumbling mill of 300 mm diameter, and three sizes of chrome steel balls were used as grinding media. Each size of ball was employed in three different lengths of the mill with the purpose to investigate the end-walls effect in the behavior ball charge. The image analysis technique was employed to identify the transition regions. A high-speed camera with maximum speed of 2000 frames/s was used to record images. Experimental data showed it was not found the end-wall effects on the transitional behavior, and this effect can be assessed in numerical studies by analyze of the specularity coefficient.
Coffee Husks Characterization for the Fast Pyrolysis Process
Authors: Tibola Fernando Lucas , de Oliveira Tiago José Pires , Carvalho Wender Santana , Ataíde Carlos Henrique , Cardoso Cássia Regina
Published: July 2017

The lignocellulosic biomass is a renewable alternative for fossil fuels. The extensive cultivation of coffee grounds in Brazil generates a large amount of residues, as coffee husks. The work aimed at performing the coffee husks characterization, investigating the viability for fast pyrolysis application. Coffee husks were dried, grinded in a knives mill and sieved using a mechanical sieving; different vibration frequencies and times were used to evaluate the effect of these variables in the size distribution. The true density was inferred for three distinct size ranges of the coffee husks, using a helium pycnometer. Proximate and ultimate analyses were performed. The analytical pyrolysis was realized at 550°C, using a micro pyrolyzer (CDS 5200), vapors was identified by a gas chromatograph and a mass spectrometer (GC-MS QP 2010 plus, Shimadzu). The influence of the particles irregular shape was evidenced in the results of size distribution. The values of true density were around 1.5 g/cm3. The smaller the particle size, the higher the true density of the sample. Coffee husks can be used to generate high added value compounds: 1,3 pentadiene, limonene and n-hexadecanoic acid. Considering the use of coffee husks bio-oil as a fuel, results indicated that the bio-oil will present high calorific value, important acidity and smaller increases in viscosity and molecular weight if compared to the bio-oil of other lignocellulosic materials.
Study of the Influence of the Underflow Diameter on the Separation Process of an Optimized Hydrocyclone for Concentration Purposes
Authors: Gonçalves S.M. , Kyriakidis Yanne Novais , Vieira Luiz Gustavo Martins , Barrozo Marcos A.S.
Published: July 2017

Hydrocyclones are equipment typically used in solid-liquid separation. Such equipment can be used with the purpose of classifying particles or concentrating suspensions. In this context, a new filtering hydrocyclone was conceived through Surface Response and Differential Evolution Algorithm techniques in order to optimize the Euler’s number. Based on this optimized geometry, the aim of the present paper was to verify the influence of the underflow diameter on the overall separation process at 147 kPa on the same optimized hydrocyclone geometry, but without the filtration effect, by performing laboratory experiments and CFD simulations using the commercial software Fluent®. The results showed that the use of the smallest underflow diameter increased up to 44% (v/v) the concentration of the underflow stream, compared to the suspension initially fed, with an Euler’s number of 862. Despite a small decrease (14%) in the total efficiency and an increase from 12.01 to 16.05 of the reduced cut size diameter, compared to the underflow diameter originally used in the optimization procedure, the benefits of recovering liquid by reducing the underflow diameter outweigh these disadvantages.
The Influence of Pr and Mg Content on the Hydrogen Decrepitation of LaNi-Based Battery Alloys
Authors: Soares Edson Pereira , Zarpelon Lia Maria Carlotti , Faria R.N.
Published: July 2017

This paper reports the results of investigations of the hydrogenation and decrepitation of some LaNi-based hydrogen storage cast ingot alloys. A decrepitation procedure for battery negative electrode alloys has been applied using a combination of hydrogen pressure and heating from room temperature to 773K. It has been shown that the Pr and Mg content have a significant influence on the microstructures of the hydrogenated alloys and decrepitation efficiency. Alloys with high concentration of Pr and Mg required an activation quenching treatment for starting the absorption of hydrogen. The decrepitated materials were characterized by scanning electron microscopy (SEM). Electrodes for alloy discharge capacity studies were produced using a nickel screen and electrochemical measurement were carried out in a standard three-electrode cell. The H content of the negative electrode, expressed as the number o H atoms (n) per formula unit, was determined using the measured storage capacity.
Comparative Study of the Optimized Hydrocyclones H13 and HCOT3 for Maximum Liquid Recovery
Authors: Salvador Fernanda Falqueto , Kyriakidis Yanne Novais , Barrozo Marcos A.S. , Vieira Luiz Gustavo Martins
Published: July 2017

In industrial applications, it is very common to use multiple hydrocyclones in parallel to improve the separation. This equipment employs the centrifugal field to promote solid-liquid or liquid-liquid separation. In cases where there is interest in recovering the liquid phase by removing the maximum amount of dispersed phase (waste), such as in oil well drilling units and in water treatment systems, the employment of a hydrocyclone able to promote both the recovering liquid and the concentration of suspension is viable. This paper presents a comparison between two hydrocyclones considered concentrators, called H13 and HCOT3. The results obtained showed that both separators have a satisfactory capacity to concentrate aqueous suspensions, with the underflow-to-throughput ratio equivalent. The Euler number of HCOT3 hydrocyclone was 19% lower than that obtained for the H13 hydrocyclone. Moreover, the results showed that the HCOT3 has a total efficiency of separation 34% greater compared to H13.
Study of Granulated Gypsum Hardness Coming from the Granulation Process in Rotating Disk
Authors: Rodrigues Laís Maia , Pires Ricardo Francisco , de Souza Davi Leonardo
Published: July 2017

The granulation process is a unit operation with broad application in the fertilizer industry. The granular fertilizer has a better physical appearance, facility of agricultural application and elimination of fugitive dust in the production and bagging units. Phosphogypsum is a residue from the production of phosphate fertilizers. It known that for every 1 t of phosphate fertilizer produced, about 4 t of phosphogypsum are obtained, causing problems in storage and risks to the environment. Such problems may be minimized by granulating the waste phosphogypsum and using it in agriculture. This work aims at the construction of a laboratory-scale rotating disk granulator with a pre-established combination of reagents to promote granulation of the waste from phosphate fertilizer production. For construction of the equipment a theoretical study was performed in order to establish the principal variables influencing the granulation technique and the dimensions required for building the granulator. The equipment attained the expected results and the disc speed (22 to 250 rpm) and disc inclination (0 to 90 degrees) can be manipulated. In this paper three binders used were: Manioc starch, carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA), each at three different concentrations. The tests were conducted using a rotating disk granulator and hardness tests on a universal mechanical testing machine. The figures of merit used in this study were percentage particle size, hardness and sphericity of the granules obtained. With the analysis of the data, it can be concluded that the granulation process was adequate, considering the settings employed.
Characteristics of the Milk Powder Particles Lecithinated
Authors: Castejon Letícia Vieira , Almeida Eduardo Santos , Cardoso Vinícius Salgado , dos Santos Kássia Graciele , Finzer José Roberto Delalibera
Published: July 2017

The process of adding soy lecithin to milk (lecithination), followed by the agglomeration stage and drying, are the goal to increase the powder dispersion in water. This work studies the physical characteristics of milk lecithinated by the addition of raw and clarified lecithins with hydrogen peroxide, which was dried by lyophilization. The main objective was to compare the behavior between the particles of powdered milk, added 0.4% (w/v), 0.8% (w/v) and 1.0% (w/v) lecithin raw and clarified. The amount of added soy lecithin was determined on the basis of dry matter content of the full UHT milk used in the experiment. Lecithinated of fluid milk samples were put on aluminum forms and frozen by contact with liquid nitrogen and were placed inside the lyophilizer chamber. The lyophilization stage was carried out for approximately 7 hours under vacuum of 460 mmHg and temperature of -38 ° C. Dried samples were fragmented in porcelain pestle and kept in oven at 40°C until analyses. The powder milk added with lecithin clarified had shorter wettability to the concentration of 1.0% (w/v), the lowest percentage of retained insoluble after solubilization in water and the micrographs of the powder showed that most adding more clarified formed lecithin agglomerates of the milk powder added lecithin raw. So, the lecithin clarified give improvements in the particles for the milk added.
Effect of Bactericidal Elements Addition on the Microstructure and Mechanical Properties of Ti34Nb Alloy
Authors: Gil Esther , Amigó Angèlica , Muñoz Anna Igual , Amigó Vicente
Published: July 2017

The functionalization of β-Ti alloys by the addition of small amounts of bactericidal elements is interesting for biomedical applications. Thus, alloying pure titanium with highly biocompatible elements such as Nb or Ta, stabilizes the β phase of the resulting alloy although they can also include difficulties during the fabrication process due to their refractory nature. This work studies the effect of small additions of Ag and Cu (1.5 to 3 wt.%) on the microstructure and mechanical properties of the Ti34Nb (wt.%) alloy processed by powder metallurgy. The blend elemental powders were mixed (30 rpm during 30 min). The samples were compacted at 600 MPa and sintered at 1250 oC during 3 hours. The microstructure was analyzed by X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscope with X-Ray Spectroscopy (FE-SEM/EDS). The mechanical properties were obtained by bending tests; the elastic modulus was measured by ultrasonic methods and the porosity by Archimedes test. Cu addition generates the appearance of α phase sheets inside the β phase grains. Cu also decreases the open porosity and increases the closed porosity of the material. On the contrary, Ag addition does not influence the stabilization of the β phase and it does not modify the density, thus the total porosity of the resulting material. With respect to the influence of the alloying elements on the elastic modulus (E) of the alloys, the E of the Ti34Nb (76.8 GPa) increases with the Cu addition (92.6 GPa) and decreases with the Ag one (68.9 GPa). Therefore, silver addition, which does not modify the microstructure and slightly decrease the mechanical properties of the Ti34Nb, can be considered a good alloying element to provide antibacterial features to the titanium alloy without losing performance.
Human Dermal Fibroblast Adhesion on Ti-7.5Mo after TiO2 Nanotubes Growth
Authors: do Amaral Escada Ana Lucia , Trujillo Nathan , Popat Ketul C. , Rosifini Alves Claro Ana Paula
Published: July 2017

Vertically aligned TiO2 nanotubes have been grown on Ti-7.5Mo by anodization and the growth of human dermal fibroblast on such nanotubes were investigated. The TiO2 nanotubes were characterized by means of field emission scanning electron microscopy (FEG-SEM) and X-ray diffraction (XRD). To characterize the cell morphology and viability it was used a scanning electron microscope and MTT assay after 1, 4 and 7 days cell. The results showed that cell proliferation was evident over the duration of experiment, but it was higher at day 4 on polished Ti-7.5Mo.
Production Methods of Thermoelectric Materials and their Main Characteristics
Authors: Polozine Alexandre , Schaeffer Lirio
Published: July 2017

This paper is intended for the analysis of the fabrication of Thermoelectric Materials with emphasis on the use of Powder Technology including the use of Powder Technology. Main characteristics of them are considered. The recycling of thermoelectric material pieces is shown.
Iron Nanoparticles Coated with Nanostructured Carbon: Synthesis and Application in Glucose Biosensors
Authors: Roman R.L. , Gonçalves J.P.Z. , Fernandes S.C. , Silva Lucinao Luiz , Dal Magro J. , Mello J.M.M. , Fiori Márcio Antônio
Published: July 2017

Nanowires of carbon coated ferric oxide (Fe2O3/C) have been studied to be applied at an electrochemical glucose biosensor as a new type of carbon paste electrode (CPE) modifier. The Fe2O3/C was synthesized by adapting co-precipitation hydrothermal route. Firstly, amperometric sensor based on a modified CPE doped with Fe2O3 has been developed and compared with CPE doped with Fe2O3/C for hydrogen peroxide (H2O2) determination. The performance evaluations for the modified materials and sensors were studied in detail through cyclic voltammetry (CV) method. After, the electrochemical sensor performance was also evaluated for glucose oxidase (GOx) response biosensor due to considerable interest in the blood sugar control. The results demonstrate that the GOx retains its biocatalytic activity toward the oxidation of glucose and that the bioelectrode modified by the Fe2O3/C matrix has potential for use in biosensors and other bioelectronics devices.