Mechanism-based characterization of the texture influence on the corrosion and corrosion fatigue properties of zinc-based wrought magnesium alloys

基于机制的织构对锌基变形镁合金腐蚀和腐蚀疲劳性能影响的表征

• 批准号: 461435286
• 负责人: Dr. Dietmar Letzig
• 金额: --
• 依托单位: Lehrstuhl für Werkstoffprüftechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/461435286?language=en
• 关键词: Mechanism; based; characterization; texture; influence

The proposal aims to investigate the damage mechanisms of RE- and Ca-containing extruded Mg-Zn alloys under cyclic loading in air and corrosive media. The results of previous work allow the conclusion that RE- and Ca-containing extruded Mg alloys have the potential of significantly improved properties under fatigue loading and stress corrosion cracking (SCC) conditions compared to the Al-containing Mg standard alloys. By adding suitable alloying elements and setting suitable extrusion parameters, Mg alloys with fine grain sizes and simultaneous texture weakening are to be produced, i.e. by changing the deformation mechanism, properties such as formability, increased fatigue strength, increased corrosion resistance and reduced subcritical crack propagation are to be combined. The formation of twins shall be reduced, not only by weak textures and fine grain sizes but also by homogeneous grain size distributions and suitable precipitates which reduce the formation of twins and at the same time do not hinder the slipping processes. By increasing the fatigue strength on the one hand and the corrosion resistance, on the other hand, the aim is also to achieve a significant improvement of the resistance to SCC. The different processing parameters and the resulting microstructure are to be investigated for their influence on the damage mechanisms under cyclic loading in air and under SCC conditions, and a fundamental process-microstructure-property relationship is to be derived from the findings. By correlating the course of the stress-strain hystereses with the microstructural changes, the complex interaction of the texture, the resulting anisotropy, and the tension-compression asymmetry under cyclic loading in the corrosive medium is to be characterized. The understanding of the process-microstructure-property relationships allows the development of a new group of high-performance extruded Mg alloys and the knowledge transfer to the fatigue and corrosion behavior of Mg sheet alloys in general, which forms a basis for sheet alloy development through cast rolling. Although the topic has a high scientific and economic potential, it has not been investigated yet, nor have the present damage mechanisms been researched regarding the texture influence on fatigue behavior and in particular the SCC.

该提案旨在研究含稀土和钙的挤压镁锌合金在空气和腐蚀介质中循环载荷下的损伤机制。之前的工作结果表明，与含铝镁标准合金相比，含稀土和钙挤压镁合金在疲劳载荷和应力腐蚀开裂（SCC）条件下具有显着改善性能的潜力。通过添加合适的合金元素并设置合适的挤压参数，可以生产出细晶粒并同时弱化织构的镁合金，即通过改变变形机制、可成形性等性能，提高疲劳强度、提高耐腐蚀性并减少亚临界裂纹扩展是要合并的。孪晶的形成不仅通过弱织构和细晶粒尺寸来减少，还通过均匀的晶粒尺寸分布和适当的析出物来减少孪晶的形成，同时不阻碍滑移过程。通过一方面提高疲劳强度，另一方面提高耐腐蚀性，目的还在于显着提高抗SCC能力。将研究不同的加工参数和由此产生的微观结构对空气中循环载荷和 SCC 条件下损伤机制的影响，并从研究结果中得出基本的工艺-微观结构-性能关系。通过将应力应变滞后过程与微观结构变化相关联，可以表征腐蚀介质中循环载荷下织构的复杂相互作用、由此产生的各向异性和拉压不对称性。对工艺-微观结构-性能关系的理解允许开发一组新的高性能挤压镁合金，并将知识转移到一般镁板合金的疲劳和腐蚀行为，这为板合金开发奠定了基础铸轧。尽管该主题具有很高的科学和经济潜力，但尚未对其进行研究，也尚未研究织构对疲劳行为（特别是 SCC）影响的现有损伤机制。