Aluminium Microstructure Analysis Gainhub

The aluminium world is in a state of radical change. We are pushing the limits of known alloys and their classes, both to enhance their performance (crossover concept [1-4]) and to create alloys containing high proportions of recycled materials [4-6]. The microstructure is a crucial factor in determining the physical and chemical properties of these specialist products. A fundamental understanding of how the aluminium matrix interacts with added elements in solid solution, primary phases, dispersoids and hardening phases, and how they interact with dislocations, is essential for optimizing manufacturing processes and the properties of finished materials.

Research, quo vadis?

Prof. Antrekowitsch, as Vice-Rector you will be responsible for research and sustainability. Do you see further potential to develop the cooperation between AMAG and MUL?

Inner values are also key for aluminium

Dr. Ramona Tosone, what influence doesmicrostructure have on theperformance of aluminium?

Does green aluminium really exist?

First things first: aluminium has a silvery color and is only green once painted or anodized. This fact is important to bear in mind when scrutinizing claims of green aluminium. Ultimately, only on closer inspection does it become clear wether an assertion is just that, i.e. colored green, or wether the statement is comprehensively technically correct.

Live and in color

Even though AlMgSi(Cu) alloys have long since become standard materials for wide-ranging applications in the field of lightweight construction, the microstructural processes that occur during their production continue to raise fascinating questions. For many years, the focus has been on cluster formation and its impact on artificial aging and the formation of hardening precipitates [1,2]. There are also new and extensive studies concentrating on the early stages of over-aging [3,4]. In contrast, however, the mechanism by which stable phases develop has been the subject of considerably less attention to date, and information on the topic remains inconclusive [5-8]. In some ways, this is hardly surprising, given that stable phases in AlMgSi(Cu) alloys are typically undesirable in the finished product, as they do not make an appreciable contribution to material strength.

Forming characteristics of 6xxx alloys

From hoods and doors to fenders and deck lids, AMAG automotive sheets have wide-ranging automotive applications and meet numerous requirements. In addition to mechanical and forming characteristics, these sheets possess excellent corrosion resistance, process-stable weldability and bondability combined with outstanding surface quality for defect-free painting.

Ready for take-off

As extensively detailed in AluReport 01/2023, AMAG components has drawn up a master plan, charting the future direction of the company. This masterplan, which will be implemented in several phases at the company’s Übersee and Karlsruhe sites, aims to improve all operational KPIs with the aim of giving customers the best possible service.

Excellence as standard

Rain is hardly unusual in the autumn. In 2023, however, autumn brought a very different kind of rain to AMAG - with awards raining down on the company. In the space of a few weeks, AMAG received four awards in different disciplines, from sustainability to intelligent data use, and from reporting to outstanding economic performance.

Sustainable aluminium production

Aluminium can be made “greener” through recycling, energy efficiency, durability and systematic application of lightweight design concepts

To Si or not to Si

The hot rolling process has a significant influence on the formability of Al-Mg-Si sheets (6xxx alloys) used in automotive bodywork. AMAG researchers collaborating with scientific partner institutes have identified a physical cause for this connection in the key AA6016 alloy: pure silicon precipitates grow at grain boundaries during and after hot rolling. If they grow too large, they do not disappear completely during solution heat treatment and reduce the material’s formability. To prevent this, AMAG uses a specifically developed material model that pre-calculates the growth of silicon precipitates. This computer-based model rapidly optimizes hot rolling pass schedules to achieve the best possible formability in sheets for the automotive industry.

Is there room for any more

The youngest member of the AMAG CrossAlloy® family, CrossAlloy®.68, is a textbook example of the adaptation of material characteristics using thermomechanical processes and structural control. In the pursuit of recycling-friendly wrought aluminium alloys, a typical 6xxx alloy was supplemented with a high iron content, as is common in 8xxx alloys used for foil applications. The experiment provided some interesting observations.