Molecular dynamics simulations of multiphase Al-Cu and Al-Cu-Mg alloys: Strengthening phases and laser irradiation

多相 Al-Cu 和 Al-Cu-Mg 合金的分子动力学模拟：强化相和激光照射

• 批准号: 461606136
• 负责人: Professor Dr. Johannes Roth, since 4/2023
• 金额: --
• 依托单位: Institut für Funktionelle Materie und Quantentechnologien
• 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/461606136?language=en
• 关键词: Molecular; dynamics; simulations; multiphase; Al

Molecular dynamics simulations of multiphase Al-Cu and Al-Cu-Mg alloys: Strengthening phases and laser irradiation Alloys containing precipitates are used in many applications because of their high strength. Aluminium based Al-Cu and Al-Cu-Mg alloys are particularly popular in lightweight construction and aviation technology. Thermal aging of these alloys leads to precipitation of complex binary and ternary phases which form depending on temperature, aging time and concentrations of alloying elements. The strength of the alloy increases because these precipitates hinder dislocation motion effectively. Further improvement of the mechanical properties can be achieved by laser irradiation which can lead to phase transformations or generation of dislocations. As a result the strength can increase further and the propagation of fatigue cracks can be retarded. In this project molecular dynamics simulations are performed in order to gain insight into the underlying mechanisms of the improved material properties. For this purpose an interaction potential for Al-Cu-Mg is developed which takes into account electron temperature dependency as recommended for simulations of laser machining. The simulations focus on interactions of dislocations with complex precipitates, the investigation of effects resulting from laser irradiation, and improved modelling of precipitate phases using Monte Carlo / molecular dynamics hybrid simulations. The aim is to understand the influences of different factors as crystal structure of the precipitate, coherency strain or intensity and pulse duration of laser irradiation on the strength. It is intended to identify the main contributions of precipitation strengthening in Al-Cu and Al-Cu-Mg alloys. The absorption as well as electron and coupling parameters are positiondependent for laserirradiation of inhomogeneous materials. Furthermore, electron temperature dependent potentials developed in this project are applied in the simulations. Considering these dependencies requires substantial further development of the molecular dynamics software IMD. Furthermore, the implementation of the Monte Carlo molecular dynamics hybrid simulation in IMD will be extended in order to simulate the vacancy assisted formation of more realistic precipitates.

多相 Al-Cu 和 Al-Cu-Mg 合金的分子动力学模拟：强化相和激光照射含有沉淀物的合金由于其高强度而在许多应用中使用。铝基铝铜和铝铜镁合金在轻质结构和航空技术中特别受欢迎。这些合金的热老化导致复杂的二元相和三元相的沉淀，其形成取决于温度、老化时间和合金元素的浓度。由于这些析出物有效地阻碍位错运动，因此合金的强度增加。机械性能的进一步改善可以通过激光照射来实现，激光照射可以导致相变或位错的产生。结果，强度可以进一步增加并且疲劳裂纹的扩展可以被延迟。在该项目中，进行分子动力学模拟是为了深入了解改进材料性能的潜在机制。为此，开发了 Al-Cu-Mg 的相互作用势，其中考虑了激光加工模拟所建议的电子温度依赖性。模拟的重点是位错与复杂析出物的相互作用，研究激光照射产生的影响，以及使用蒙特卡罗/分子动力学混合模拟改进析出物相的建模。目的是了解沉淀物的晶体结构、相干应变或激光照射的强度和脉冲持续时间等不同因素对强度的影响。其目的是确定 Al-Cu 和 Al-Cu-Mg 合金中沉淀强化的主要贡献。对于非均匀材料的激光照射，吸收以及电子和耦合参数与位置相关。此外，该项目中开发的电子温度相关电势也应用于模拟中。考虑到这些依赖性需要进一步开发分子动力学软件 IMD。此外，蒙特卡罗分子动力学混合模拟在IMD中的实施将得到扩展，以模拟空位辅助形成更真实的沉淀物。