Johannes Albert Österreicher

• PhD
• Senior Scientist at Austrian Institute of Technology

In the automotive industry Al-Mg-Si alloys are often chosen for high strength extruded profiles. However, the production of such profiles can be challenging for high alloy contents. Among several processing steps, the homogenization heat treatment before extrusion is readily accessible to modifications to improve high temperature formability. In th...

Proper design of the heat treatments of metallic materials is crucial for creating a suitable microstructure resulting in the desired properties. In this paper, we present a multi-component simulation procedure for the quantitative prediction of yield strength, fracture strain, and fracture toughness of precipitation-hardened alloys, with special e...

Characterization of Mg-Si precipitates is crucial for optimizing the homogenization heat treatment of Al-Mg-Si alloys. Although sample preparation is key for high quality scanning electron microscopy imaging, most common methods lead to dealloying of Mg-Si precipitates. In this article we systematically evaluate different sample preparation methods...

Aluminium extrudate used for safety parts in cars need to exhibit high yield strength and ductility, a combination that is not easily achieved. In this work, the mechanical properties and microstructure of profiles with a yield strength greater than 280MPa achieved by two different artificial ageing treatments were studied. Profiles from one of the...

In response to escalating climate change concerns, the transition to renewable energy systems, including hydrogen-based technologies, is imperative. Proton exchange membrane fuel cells (PEMFCs), which produce electricity through the electrochemical reaction of hydrogen and oxygen without greenhouse gas emissions, are at the forefront of this transi...

Improving the deformation behaviour of titanium alloys at intermediate temperatures is crucial for cost and energy savings in forming processes. In this context, the modification of the microstructure prior to forming is of great importance. Here we show how the deformability of α-β titanium sheets at 500°C can be significantly increased via a tail...

Reliable determination of the elastic moduli of metals can be quite demanding, especially as the apparent elastic modulus of metals is known to decrease with deformation. Traditionally, this dependence on plastic strain has been investigated through various tensile tests, but discrepancies persist across the different approaches. Here we compare se...

The recycling of aluminium sheet metal typically involves shredding and re-melting, processes which are both energy-intensive and challenged by the presence of metallic contaminants. To mitigate these issues, this study explores an alternative approach: the re-manufacturing of deep-drawn parts directly from scrap aluminium sheets, thus bypassing th...

Standard ultrasonic thickness measurements require the sound velocity of the sample to be known and vice versa. We present a method, which we have termed combined mode local acoustic spectroscopy (CoMLAS) for simultaneously determining a plate's thickness and sound velocities without requiring such a priori knowledge. It is based on a combination o...

Al-Mg-Si alloys are an important class of Al wrought alloys. Further increasing their strength has significant economic potential. Previous approaches were focusing on increasing the amount of the main hardening elements Mg and Si, adding Cu and Zn for additional hardening potential, and adding dispersoid-forming elements such as Cr and Zr. In term...

Precipitation processes in age hardenable aluminium alloys are often investigated by differential scanning calorimetry (DSC). The endothermic and exothermic peaks of the DSC signal correspond to the dissolution and formation of phases, respectively. However, parasitic effects can lead to an unintended curvature of the DSC signal. Although a baselin...

Dissimilar welding of Ti and Al alloys is challenging due to the potential formation of brittle intermetallics, which can compromise weld strength. Friction stir welding (FSW) is an advanced joining method with the potential to drastically reduce or prevent the formation of intermetallic phases because melting is avoided. However, in previous studi...

Microstructure analysis via electron backscatter diffraction has become an indispensable tool in materials science and engineering. In order to interpret or predict the anisotropy in crystalline materials, the texture is assessed, e.g. via pole figure diagrams. To ensure a correct characterization, it is crucial to align the measured sample axes as...

Aluminum scrap is often contaminated with steel parts, leading to accumulation of Fe in recycled Al alloys. Consequently, low limits for Fe in Al wrought alloys are difficult to meet by recycling without dilution with primary Al. Wrought alloys with a higher tolerance for Fe could help overcome this problem and improve the sustainability of Al wrou...

The characterization of Zr-containing dispersoids in aluminum alloys is challenging due to their broad size distribution, low volume fraction, and heterogeneous distribution within the grains. In this work, small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) were compared to scanning electron microscopy (SEM) and transmiss...

AA2024, a high-strength aluminum wrought alloy, is widely used in the production of aircraft components, for example, frames and stringers. While the alloy is relatively soft and formable in the solution heat treated and quenched state (W temper), rapid onset of natural ageing increases hardness and decreases ductility within few hours, creating a...

Sammelband der wissenschaftlichen Papers und Extended Abstracts der Konferenz „12. Ranshofener Leichtmetalltage 2022“ des LKR Leichtmetallkompetenzzentrum Ranshofen unter der Leitung von Dr. Christian Chimani. Proceedings of 12. Ranshofener Leichtmetalltage conference, Salzburg, Austria, 2022

Solution heat treatment increases the formability of 7xxx series aluminum alloys by dissolution of nanoscale hardening phases. However, subsequent natural aging at room temperature partly reverses this process within a few hours, posing a logistical challenge to industrial operations as formability decreases and springback increases. Hence, non-des...

We developed four high-strength Al-Mg-Si alloys; to increase comparability, the Mg/Si ratio, as well as Mn, Cu, and Zr contents were held constant. The influence of total Mg+Si content and Zn/Cr additions were studied. All alloys were cast, homogenized, both rolled and extruded, and artificially aged in the same way to ensure reproducibility. Micro...

Coarse grains at or near the surfaces of extruded aluminum profiles can have a major detri-mental influence on their ductility and surface quality. Thus, the extrusion industry aims to minimizecoarse grains while increasing the productivity of the process. Peripheral Coarse Grains (PCG) de-velop depending on local state variables such as temperatur...

Warm deep-drawing of pre-aged (under-aged) blanks of 7xxx series aluminum alloys (Al-Zn-Mg) at moderate temperatures of roughly 120–230°C is a promising route for producing parts with considerable geometrical complexity, good paint bake hardening response, and, thus, excellent final mechanical properties. Furthermore, oil-based lubricants can be us...

Proper design of the homogenization heat treatment of 6000 series Al wrought alloys is crucial for processes such as hot rolling and extrusion. Important aspects are the precipitation and growth of dispersoids and the dissolution and re-precipitation of Mg-Si-precipitates. Studying these processes is laborious and experimentally demanding, limiting...

During the homogenization heat treatment of 6xxx series aluminum alloys, nanoscale precipitates—commonly named dispersoids—are formed that influence material properties during further processing by extrusion, forging, or rolling, as well as final product quality. Obtaining dispersoid size distributions is commonly accomplished by manually counting...

Hochfeste Aluminium-Flugzeuglegierungen bieten auch Leichtbaupotenzial für den Automobilbau. Mittels angewandter Forschung werden wirtschaftliche Prozessketten entwickelt. So sollen die Siebentausender attraktiver für den Einsatz im Automobilbau werden. Eine Schlüsselrolle spielt dabei die Halbwarmumformung stabilisierter Platinen.

Development of improved lithium-containing compounds and alloys are critical to meet energy reduction roadmaps. However, progress in many applications is hindered by the inability to spatially resolve the distribution of lithium at the microscale using conventional analytical techniques such as energy dispersive X-ray spectroscopy (EDS) in the scan...

Room-temperature cyclic deformation of age-hardenable alloys can produce similar strength as artificial ageing in much shorter time, but industrial applicability is limited due to the high number of required cycles. As an alternative, fewer cyclic deformation steps can be combined with traditional artificial ageing: Introducing a small plastic defo...

The quantification of lithium in electron microscopes by energy-dispersive X-ray spectroscopy (EDS) is highly challenging due to the low energy of the characteristic X-rays. Only special windowless detectors can detect Li, yet the sensitivity is suboptimal (i.e., ~20 wt. %). We introduce the use of quantitative backscattered electron microscopy in...

Two-step ageing of 7xxx series alloys can reduce ageing time while obtaining similar mechanical properties as a longer isothermal heat treatment. In this paper, an intermediate deep-drawing step at 120–160 °C is introduced to produce elongated cup–shaped parts with near-T6 strength. A Cu-containing (Alclad 7075) and a non-standard low-Cu alloy (702...

Der Fokus der 11. Tagung stand klar im Zeichen von Dekarbonisierung und Digitalisierung. Die erste Session „Werkstoffentwicklung und Materialcharakterisierung“ war geprägt durch die Präsentation neuartiger Legierungskonzepte im Aluminium- und Magnesiumbereich. Die zweite Session „Prozessentwicklung – experimentell und numerisch“ enthielt Vorträge z...

The quantification of lithium in electron microscopes by energy-dispersive X-ray spectroscopy (EDS) is highly challenging due to the low energy of the characteristic X-rays. Only special windowless detectors can detect Li, yet the sensitivity is suboptimal (i.e., ~20 wt. %). We introduce the use of quantitative backscattered electron microscopy in...

Due to their high specific strength, magnesium alloys are promising materials for further lightweighting in mobility applications. In contrast to casting and forming processes, additive manufacturing methods allow high degrees of geometrical freedom and can generate significant weight reductions due to load-specific part design. In wire arc additiv...

Aluminium alloys of the 7xxx series are attracting the attention of automakers due to their high specific strength. However, widespread use of 7xxx series alloys for the production of car parts from sheet metal has so far been prevented due to their low formability at room temperature and the fact that conventional automotive paint-bake cycles are...

During deep‐drawing of Al‐Mg sheet at room temperature, stretcher‐strain marks can appear on the material's surface. Such parts are not suitable for car outer body applications because the visually unappealing marks are still visible after painting. In this paper, the occurrence of surface marks on a miniaturized engine hood is significantly reduce...

Due to their high specific strength, EN AW-7xxx aluminium alloys are promising materials for reducing the weight of automotive structural parts. However, their formability at room temperature is poor due to pronounced natural ageing. Therefore, we investigated hot stamping and W-temper forming for EN AW-7075 and a modified variant of EN AW-7021. Fo...

Attenuation of Rayleigh-type surface acoustic waves induced by grain-boundary scattering is studied experimentally and theoretically by an effective medium approach. A frequency domain opto-acoustic laboratory setup, capable of measuring a coherent Rayleigh wave response by emulating an ensemble average via spatial averaging, is presented. Measurem...

High strength Al-Zn-Mg(-Cu) alloys are rarely used in the automotive industry due to pronounced natural ageing after quenching and resulting poor formability at room temperature. Furthermore, the paint bake response is often suboptimal. To overcome these challenges, we performed various low temperature pre-ageing treatments followed by storage at r...

Measuring the dimensions and number density of nanoparticles dispersed in a solid matrix is usually accomplished via transmission electron microscopy (TEM) which suffers from high cost, low throughput, and small analytical volume. In comparison, scanning backscattered electron microscopy is inexpensive, requires little sample preparation, and allow...

Sicherheitsbauteile aus Aluminium unterliegen höchsten Anforderungen im Fahrzeugbau. Das Leichtmetallkompetenzzentrum Ranshofen und Hammerer Aluminium Industries Extrusion haben die Crasheigenschaften eines Strangpressprofils mittels Legierungsmodifikation und geometrischer Anpassung des Querschnitts verbessert. Dabei erhöhten sie die Energieabsorp...

Safety components made of aluminium have the highest requirements in vehicle design. As part of a customer project, the crash properties of an extruded profile are improved by means of alloy modification and geometric adaptation of the cross section. An increase in energy absorption and reduction of cracking has been achieved.

Die Erfindung betrifft Verfahren zur Herstellung eines Objektes für optische Anwendungen aus einer Aluminiumbasislegierung, wobei das Objekt mit gegebenenfalls durchgehenden Löchern ausgebildet ist, wobei ein Objekt aus einer Aluminiumbasislegierung bereitgestellt wird, wonach im Objekt intrakristalline Ausscheidungen gebildet werden, wonach die in...

The ever-increasing requirements of the automotive industry in terms of crash performance necessitate the development of high strength modifications of the EN AW-6082 alloy. The high amounts of strengthening elements such as Mg, Si, Cr, Mn, and Cu can lead to poor extrudability. The present work shows the impact of microstructure on the crash perfo...

The ever-increasing requirements of the automotive industry in terms of crash performance, short- and long-time mechanical properties, corrosion resistance, and recrystallization stability of extruded profiles necessitate the development of high strength modifications of the EN AW-6082 alloy. However, high amounts of strengthening elements such as...

The ever-increasing requirements of the automotive industry in terms of crash performance necessitate the development of high strength modifications of the EN AW-6082 alloy. High amounts of strengthening elements such as Mg, Si, Cr, Mn, and Cu can lead to poor extrudability. The present work presents a statistical method for analysing the parameter...

Aluminium ist der Leichtbauwerkstoff der Gegenwart und der Zukunft. Durch den geschickten Einsatz von Aluminium können neue Leichtbaulösungen verwirklicht werden, die sonst nur schwer oder nicht zu realisieren gewesen wären. Der Werkstoff Aluminium bietet ein hohes Maß an Entwicklungspotential. Hier stehen wir erst am Anfang der Entwicklung im Verg...

The ever-increasing requirements of the automotive industry in terms of crash performance, short- and long-time mechanical properties, corrosion resistance, and recrystallization stability of extruded profiles necessitate the development of high strength modifications of the EN AW-6082 alloy. However, high amounts of strengthening elements such as...

The kinetics of glucose oxidase (GOD) and horseradish peroxidase (HRP) on a transparent gelatin–ionic liquid functional polymer has been investigated using a colorimetric assay of H2O2 with phenol-4-sulfonic acid and 4-aminoantipyrine, as color-generating precursors.The effect of different ionic liquids 1-ethyl-3-methyl-imidazolium ethyl sulfate ([...

The kinetics of Glucose oxidase (GOD) and Horseradish peroxidase (HRP) on a transparent Ion Jelly biopolymer has been investigated using a colorimetric assay of H2O2 with phenol-4-sulfonic acid and 4-aminoantipyrine, as color-generating precursors. The activity of GOD and HRP on the Ion Jelly biopolymer solid disk formed in the bottom of the well E...

The kinetics of Glucose oxidase (GOD) and Horseradish peroxidase (HRP) on a transparent Ion Jelly biopolymer has been investigated using a colorimetric assay of H2O2 with phenol-4-sulfonic acid and 4-aminoantipyrine, as color-generating precursors. The activity of GOD and HRP on the Ion Jelly biopolymer solid disk formed in the bottom of the well E...