FG Werkstofftechnik

12 Items

Recent Submissions
Bracket fungi, natural lightweight construction materials: hierarchical microstructure and compressive behavior of Fomes fomentarius fruit bodies

Müller, Cecilia ; Klemm, Sophie ; Fleck, Claudia (2021-02-10)

Bracket fungi such as Fomes fomentarius (“tinder fungus”), have strong, light and tough fruit bodies that make them interesting role-models for bio-inspired, biodegradable applications. So far, little is known about the relation between their microstructure and mechanical properties, information needed for designing novel composites. The fruit bodies (mycelia) of tinder fungus are hierarchicall...

Theoretical Prediction of P-Triphenylene-Graphdiyne as an Excellent Anode Material for Li, Na, K, Mg, and Ca Batteries

Salavati, Mohammad ; Alajlan, Naif ; Rabczuk, Timon (2021-03-05)

The efficient performance of metal-ion batteries strongly depends on electrode materials characteristics. Two-dimensional (2D) materials are among promising electrode materials for metal-ion battery cells, owing to their excellent structural and electronic properties. Two-dimensional graphdiyne has been recently fabricated and revealed unique storage capacities and fast charging rates. The curr...

Effect of hot isostatic pressing on densification, microstructure and nanoindentation behaviour of Mg–SiC nanocomposites

Hübler, Daniela ; Ghasemi, Alireza ; Riedel, Ralf ; Fleck, Claudia ; Kamrani, Sepideh (2020-05-13)

The production of fully dense nanocomposites with a homogeneous distribution of nanoparticles through powder metallurgy (PM) techniques is challenging. Additionally to mechanical milling, pressing and sintering, a final consolidation process is needed to fully densify the nanocomposite. Hot isostatic pressing (HIP) is a promising alternative method to other hot forming processes to eliminate po...

Metal‐Specific Biomaterial Accumulation in Human Peri‐Implant Bone and Bone Marrow

Schoon, Janosch ; Hesse, Bernhard ; Rakow, Anastasia ; Ort, Melanie J. ; Lagrange, Adrien ; Jacobi, Dorit ; Winter, Annika ; Huesker, Katrin ; Reinke, Simon ; Cotte, Marine ; Tucoulou, Remi ; Marx, Uwe ; Perka, Carsten ; Duda, Georg N. ; Geissler, Sven (2020-08-03)

Metallic implants are frequently used in medicine to support and replace degenerated tissues. Implant loosening due to particle exposure remains a major cause for revision arthroplasty. The exact role of metal debris in sterile peri‐implant inflammation is controversial, as it remains unclear whether and how metals chemically alter and potentially accumulate behind an insulating peri‐implant me...

Nanofatigue behaviour of single struts of cast A356.0 foam: cyclic deformation, nanoindent characteristics and sub-surface microstructure

Schmahl, Merle ; Märten, Anke ; Zaslansky, P. ; Fleck, Claudia (2020-08-04)

Struts are the main load carrying elements in cyclically loaded open cell metal foams. Little is known about the local fatigue behaviour and the influence of the microstructure on nanoscale deformation mechanisms. Different to the bulk counterpart, the millimetre-sized struts in precision-cast AlSi7Mg0.3 foams contain only 1–2 Al-dendrites, Si-Al-eutectic and intermetallic phases. We applied cy...

Hierarchical levels of organization of the Brazil nut mesocarp

Sonego, Marilia ; Fleck, Claudia ; Pessan, Luiz Antonio (2020-04-22)

Aiming to understand Nature´s strategies that inspire new composite materials, the hierarchical levels of organization of the Brazil nut (Bertholletia excelsa) mesocarp were investigated. Optical microscopy, scanning electron microscopy (SEM), microtomography (MicroCT) and small-angle X-ray scattering (SAXS) were used to deeply describe the cellular and fibrillary levels of organization. The me...

Development and Characterization of Mg-SiC Nanocomposite Powders Synthesized by Mechanical Milling

Penther, Daniela ; Fleck, Claudia ; Ghasemi, Alireza ; Riedel, Ralf ; Kamrani, Sepideh (2017-07-03)

Magnesium powder in micron scale and various volume fractions of SiC particles with an average diameter of 50 nm were co-milled by a high energy planetary ball mill for up to 25 h to produce Mg-SiC nanocomposite powders. The milled Mg-SiC nanocomposite powders were characterized by scanning electron microscopy (SEM) and laser particle size analysis (PSA) to study morphological evolutions. Furth...

Enhanced Strength and Ductility in Magnesium Matrix Composites Reinforced by a High Volume Fraction of Nano- and Submicron-Sized SiC Particles Produced by Mechanical Milling and Hot Extrusion

Kamrani, Sepideh ; Hübler, Daniela ; Ghasemi, Alireza ; Fleck, Claudia (2019-10-21)

In the present study, Mg nanocomposites with a high volume fraction (10 vol %) of SiC particles were fabricated by two approaches: mechanical milling and mixing, followed by the powder consolidation steps, including isostatic cold pressing, sintering, and extrusion. A uniform distribution of the high content SiC particles in a fully dense Mg matrix with ultrafine microstructure was successfully...

Development of cortical bone biomarkers for the prediction of femur strength

Iori, Gianluca (2019)

Osteoporosis is a skeletal disease caused by the imbalance between bone resorption and formation. In osteoporosis, the risk of fracture increases due to the structural deterioration of the bone. Hip fractures are associated with increased mortality and morbidity and lead to a decline in the quality of life. Due to these reasons, hip fractures represent a principal component of the total social ...

Structure-function relationships in Macadamia integrifolia seed coats – fundamentals of the hierarchical microstructure

Schüler, Paul ; Speck, Thomas ; Bührig-Polaczek, Andreas ; Fleck, Claudia (2014-08-07)

The shells/coats of nuts and seeds are often very hard to crack. This is particularly the case with Macadamia seed coats, known to exhibit astoundingly high strength and toughness. We performed an extensive materials science characterization of the complex hierarchical structure of these coats, using light and scanning electron microscopy in 2D as well as microCT for 3D characterization. We dif...

Structure and molecular dynamics of thin films of homopolymers and miscible polymer blends

Madkour, Sherif A. (2018)

In recent years, research on nanoscale confinement of polymers has witnessed topical investigations in attempt to tune polymer properties on demand. One of the most studied forms of nanoconfinement are thin films, where 1D confinement results from the reduction of the film thickness. For these systems, it is crucial to understand how confinement affects the glass transition phenomenon and the a...

Characterization and mechanical properties investigation of the cellulose/gypsum composite

Nindiyasari, Fitriana ; Griesshaber, Erika ; Zimmermann, Tanja ; Manian, Avinash Pradip ; Randow, Clemens ; Zehbe, Rolf ; Fernandez-Diaz, Lurdes ; Ziegler, Andreas ; Fleck, Claudia ; Schmahl, Wolfgang W. (2016)

We synthesized cellulose/gypsum composites in the presence and absence of sodium alginate and investigated the interaction between the composite components as well as the mechanical properties of the final composites. Four different types of cellulose fiber materials were used: cellulose UFC100, cellulose B400, nanofibrillated cellulose, and Lyocell fiber. For all investigated composites the to...