Superimposed Dispersoid Hardening and Age Hardening of Aluminium Alloys

该项目的目的是通过叠加分散硬化和沉淀硬化的新方法生产高强度铝合金。这首先需要对两种硬化机制中温度依赖动力学和沉淀形成类型的基本材料科学理解。随后，在典型的变形铝合金生产链（铸造、均质、热成型、沉淀硬化）中，工艺参数将调整到两种温度相关的动力学，从而产生具有潜在高强度水平的材料结构。在此基础上，讨论了工艺参数、材料结构和力学性能之间的材料科学相关性，并将其具体转移到生产链中以进一步提高强度。本文将对我们在前期工作中所知甚少的铝合金EN AW AlMn0.5Mg0.5（3105）进行研究，以了解其叠加析出行为和生产链的合适工艺参数。在另一种方法中，通过添加Zr，可以通过Al3Zr分散体产生额外的分散体硬化。为了有针对性地实现分散硬化和沉淀硬化的叠加，需要探索潜在生产链的不同途径。这些方法是基于典型退火温度下分散成形合金元素锰（和Zr）在铝中的扩散系数明显低于沉淀硬化合金元素镁和硅的扩散系数。在此基础上，目的是在工艺链的第一步形成相对稳定的分散体，在第二步形成不太稳定的沉淀物。如果工艺持续时间足够短，可以在较高的温度下进行第二步，以抑制显著的锰扩散（和Zr）。

The aim of the project is the production of high-strength aluminium alloys by the novel approach of superimposed dispersoid hardening and precipitation hardening. This initially requires a basic materials science understanding of the temperature dependent kinetics and types of precipitation formation in both hardening mechanisms. Subsequently, in a typical production chain of wrought aluminium alloys (casting, homogenising, hot forming, precipitation hardening), the process parameters are to be adjusted to the two temperature-dependent kinetics in such a way that material structures with potentially high strength levels result. Based on the results, the material-scientific correlations between process parameters, material structures and mechanical properties are to be discussed and specifically transferred to the production chain for a further increase in strength. The aluminium alloy EN AW AlMn0.5Mg0.5 (3105), which is to little extent known from our own preliminary work, will be investigated with regard to understanding the superimposed precipitation behaviour and suitable process parameters of the production chain. In a further approach, an additional potential for dispersoid hardening via Al3Zr dispersoids is to be created by adding Zr.For the targeted superposition of dispersoid hardening and precipitation hardening, different approaches of potential production chains are to be pursued. The approaches are based on the fact that the diffusion coefficient of the dispersoid-forming alloying element manganese (and Zr) in aluminium at typical annealing temperatures is significantly lower than the diffusion coefficient of the precipitation-hardening alloying elements magnesium and silicon. On this basis, the aim is to form the relatively stable dispersoids in a first step of the process chain and the less stable precipitates in a second step. The second step of the process chain can be carried out at higher temperatures if the process duration is short enough to suppress significant manganese diffusion (and Zr).