Scientific Events

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Metallic materials which have enabled progress over thousands of years and are produced in huge quantities (e.g. 1.8 billion tons of steels per year), are now facing severe and in part abrupt limits set by sustainability constraints and the associated legislative measures. Accelerated demand for structural alloys in key areas such as energy, construction, infrastructure, safety, mobile communication and transportation creates growth rates of up to 200% until 2050. Yet, most of these materials are energy, greenhouse gas and pollution intense when extracted, produced and manufactured. The lecture provides an introduction to this field and reviews approaches to improve the sustainability of and through structural metallic alloys. It reports about progress in direct sustainability for different steps along the value chain including CO₂-reduced primary production; recycling; scrap-compatible alloy design; contaminant tolerance of alloys; and improved alloy longevity through corrosion protection, damage tolerance and repairability for longer product use. It is also shown how structural materials enable improved energy efficiency through reduced weight, higher thermal stability, and better mechanical properties. The respective leverage effects of the individual measures on rendering structural alloys more sustainable are described. [more]

The Max-Planck-Institut für Eisenforschung GmbH (MPIE) and Bruker are pleased to announce Nanobrücken 2020: Nanomechanical Testing Conference & Bruker User Meeting, which will take place February 4–6 at MPIE located in Düsseldorf, Germany. Please save the date in your calendar and register to secure your seat at Nanobrücken 2020. [more]

Utilizing molecular dynamics simulations, we report a non-monotonic dependence of the shear stress on the strength of an external magnetic eld (H) in a liquid-crystalline mixture of magnetic and non-magnetic anisotropic particles.This non-monotonic behavior is in sharp contrast with the well-studied monotonic H-dependency of the shear stress in conventional ferro uids, where the shear stress increases with H until it reaches a saturation value. We relatethe origin of this non-monotonicity to the competing eects of particle alignment along the shear-induced direction, on the one hand, and the magnetic eld direction on the other hand. To isolate the role of these competing eects,we consider a two-component mixture composed of particles with eectively identical steric interactions, where the orientations of a small fraction, i.e. the magnetic ones, are coupled to the external magnetic eld. By increasing Hfrom zero, the orientations of the magnetic particles show a Freederickz-like transition and eventually start deviating from the shear-induced orientation, leading to an increase in shear stress. Upon further increase of H, a demixingof the magnetic particles, from the non-magnetic ones, occurs which leads to a drop in shear stress, hence creating a non-monotonic response to H. Unlike the equilibrium demixing phenomena reported in previous studies, the demixingobserved here is neither due to size-polydispersity nor due to a wall-induced nematic transition. Based on a simplied Onsager analysis, we rather argue that it occurs solely due to packing entropy of particles with dierent shear- or magnetic-eld-induced orientations. [more]

The Max-Planck-Institut für Eisenforschung GmbH in Düsseldorf is organizing the 5^th NRW-APT user meeting on November the 07^th 2019 and we would like to invite you and your research colleagues to participate in this event. This meeting will bring together scientists from North Rhine-Westphalia dealing with APT technique or correlating APT with other techniques. We want to discuss problems and share knowledge regarding sample preparation, measurement conditions, data reconstruction & analysis, etc..If you and your colleagues would like to attend this event, then please register before October 18^th 2019. There are limited places only. We are looking forward to see you in Düsseldorf! [more]

The workshop aims to provide a forum for researchers who are interested in applying advanced imaging and spectroscopy methods of electron microscopy, including aberration-corrected, in situ, environmental and low-voltage electron microscopy, to topical issues in materials science and engineering, in nanoscience, in soft matter research, in interface and surface science, and in biomaterials research. As these methods are of fundamental importance in virtually all technological fields, contributions are invited that address the broad spectrum of current materials research. Novel methodological developments will be discussed as well as topical areas of research on thin films, bulk materials, surfaces, materials at the nanoscale and at the interface between the physical and life sciences, for understanding structure‐property relationships of materials, as well as for metrology. Selected topics will be introduced by invited keynote speakers during the plenary sessions. A poster session provides room for the presentation and discussion of current research. [more]

Current level of miniaturization in everyday devices indicates that micro and nano architectures have become functional elements in electronics and diminutive mechanical-based systems. Yet, the potential of such multiscale functional elements is not fully realized due to incomplete understanding of their deformation mechanisms in application relevant loading conditions such as high strain rates (mimicking drops and impacts) and high/cryo temperatures. Even the state-of-the-art micro/nano mechanical testers are currently incapable of conducting experiments in such harsh loading environments. Thus, the mechanical properties of micro and nano scale materials are largely unknown at strain rates beyond 0.1/s and temperatures beyond 250°C or below room temperature. This premise forms the motivation of my research vision: “To investigate the small scale plasticity and failure mechanisms under extreme conditions, using novel micro/nano mechanical experimental platforms”. In this presentation, I will highlight three aspects from my previous research: i) Instrumentation and protocols for conducting extreme micro and nanomechanical testing, ii) Case studies of micro/nano scale metals and amorphous materials tested at high strain rates and high temperature combinations and iii) Sample manufacturing techniques for high through-put micro/nanomechanical testing. Specifically, I will present the work on in situ nanomechanical testing at high strain rates enabled by a custom-built hybrid piezo and microelectromechanical systems (MEMS) based testing system and the case-study on silver nanowires tested at strain rates upto ~200/s. Further, the instrumentation and protocols for micromechanical testing at combinations of high strain rates and extreme temperatures will be explained, with a case study on fused silica and silicon micropillar compression at strain rates upto 1000/s and temperatures upto 400°C. The final part of the talk will focus on my recent work with unique manufacturing methods: two-photon lithography/electrodeposition combination and localized electrodeposition, which are capable of manufacturing ideal damage-free test-beds of metallic micro/nano architectures including arrays of micropillars, microsprings and complex microlattices. [more]