Thermodynamic modeling and experimental investigation of glass-forming magnesium alloys

开发一个包含所有可能的合金化元素的可靠的镁数据库是申请人的长期目标。这将通过计算热力学结合使用DSC、X射线衍射、扫描电子显微镜/电子探针和扩散偶技术的关键实验来实现。事实证明，这减少了建立这种多组分数据库所需的时间和精力。目前的建议侧重于研究具有很大潜力的金属玻璃应用的镁三元系。其中三个系统分别是：Mg-Al-Y、Mg-Ni-Y和Mg-Cu-Y。镁基玻璃形成合金因其密度低、强度高、耐腐蚀性好、韧性高等优点而备受关注。镁基金属玻璃具有较高的抗拉断裂强度，是传统镁基晶合金最高强度的两倍多。更重要的是，文献中提到，镁基合金有可能生产出最大的块体金属玻璃。到目前为止，世界范围内的努力主要集中在通过添加不同的合金元素来提高镁基合金的非晶形成能力。目前的提议旨在通过提供一个自洽的热力学数据库来促进这些努力，该数据库可以用来确定具有最高玻璃形成能力的镁合金的最有希望的成分。与目前的试错法不同，在拟议的研究中，将使用该数据库来识别有形成块体金属非晶的倾向的成分。这可以通过鉴定呈现低位液相线表面的组合物来获得。值得注意的是，这一策略将增加获得最适合大块金属玻璃应用的镁基合金的机会，而不是传统的经验试验和错误试验。此外，所提出的策略将能够预测玻璃形成能力的成分敏感性，而现有的基于原子尺寸分布的标准无法预测这一点。该项目将使加拿大汽车和航空航天行业受益，并将为所有镁产品生产商提供新的机会。

Development of a reliable Mg database that contains all the possible alloying elements is the applicant's long term objective. This will be achieved through computational thermodynamics coupled with key experiments using DSC, XRD, SEM/EPMA and diffusion-couples techniques. This proved to reduce the time and effort necessary to establish such a multicomponent database. The current proposal focuses on investigating Mg ternary systems that have strong potential for metallic glass applications. Three of such systems are Mg-Al-Y, Mg-Ni-Y and Mg-Cu-Y. Mg-based glass-forming alloys have attracted special attention due to their low-density, high strength, excellent corrosion resistance, and high toughness. Mg-based metallic glasses exhibit high tensile fracture strength which is more than twice as high as the highest strength of conventional Mg-based crystalline alloys. More importantly, it is mentioned in the literature that Mg-based alloys have the potential to produce the largest bulk metallic glass. So far, the efforts worldwide are focussed on the improvement of the glass-forming ability of Mg-based alloys by additions of different alloying elements. The current proposal aims at contributing to these efforts by providing a self-consistent thermodynamic database that can be used to identify the most promising compositions for Mg-alloys that have the highest glass-forming ability. Unlike the current practice of trial and error method, in the proposed research, the compositions that have the tendency to form bulk metallic glasses will be identified using this database. This can be obtained through identifying the compositions that exhibit low lying liquidus surface. It is worth noting that this strategy will enhance the chance of obtaining the most suitable Mg-based alloys for bulk metallic glass applications instead of the traditional empirical trial and error experimentation. Further, the proposed strategy will enable predicting the composition sensitivity of the glass-forming ability which is not possible by the existing criteria that are based on atomic size distribution. This project will benefit Canadian automobile and aerospace industries and will provide new opportunities to all Mg products producers.