Creep resistant zinc alloys: Towards thermodynamic and mechanical stability by microalloying

该项目的目的是为锌合金提供新的合金设计策略，以提供更好的抗蠕变性。为此，一个双重的方法已经遵循在以前的项目中，其中既可用的Zn-Al-Cu-（Mg）系统的热力学数据，以及具有不同的镁含量的相应的合金的显微组织和机械性能进行了详细研究，基于压铸和几个重力铸造合金。镁的添加在这个先前的项目中产生了一些有希望的机械性能改进。因此，提出了一个新项目的建议，在此期间，将继续成功地结合热力学和微观结构/机械特性的方法。重点将放在机械（在）稳定性的机制，特别是沉淀和分解现象，通过使用高分辨率的表征方法和建模的基本热力学平衡状态。虽然变形机制的研究将首先集中在微观和纳米力学测试在不同的应变速率和温度与TEM和APT相关，以进一步阐明个别微观结构组件的作用，热力学评估将集中在一个新的合金元素，钛，以提供有前途的合金成分的指导方针。小规模的样品感应熔化与快速凝固将用于两个，纳米力学和热力学表征。这使得一个有效的联合实验计划，并利用从项目的两个部分的综合见解，如何改善微观结构的主要组成部分使用基本的热力学基础。基于对新型Zn-Al-Cu-（Mg，Ti）合金的变形特性、析出和分解现象以及由此产生的机械性能的了解，该项目旨在为具有更好的机械稳定性和抗蠕变性的Zn合金提供未来的合金设计策略。

The aim of this project is to provide new alloy design strategies for zinc alloys offering an improved creep resistance. To this end, a dual approach has been followed in a previous project, in which both the available thermodynamic data of the Zn-Al-Cu-(Mg) system as well as the microstructural and mechanical properties of respective alloys with different magnesium contents have been studied in detail, based both on a die-cast and several gravity cast alloys. The addition of magnesium has yielded some promising improvements in mechanical properties within this previous project. Therefore a proposal for a new project is made during which the successfully combined thermodynamic and microstructural/mechanical characterisation approach will be continued. The focus will be placed on the mechanisms of mechanical (in)stability and in particular on precipitation and decomposition phenomena by using high resolution characterization methods and modelling of the essential thermodynamic equilibrium states. While the investigation of deformation mechanisms will initially focus on micro- and nanomechanical testing at different strain rates and temperatures in correlation with TEM and APT in order to further elucidate the role of the individual microstructural components, the thermodynamic assessment will concentrate on a new alloying element, Ti, in order to provide guidelines for promising alloy compositions. Small-scale specimens produced by induction melting with rapid solidification will be used for both, nanomechanical and thermodynamic characterization. That allows an efficient joint experimental programme and also to capitalize on the combined insights from both parts of the project into how to improve the microstructure regarding the major components using the essential thermodynamic basis. Based on the acquired knowledge concerning deformation characteristics, precipitation and decomposition phenomena and the resulting mechanical properties of new Zn-Al-Cu-(Mg, Ti) alloys, the projects aims to provide future alloy design strategies for Zn alloys with improved mechanical stability and creep resistance.