Relationships linking alloying elements, solidification, geometry and cracking during pulse laser additive manufacturing of Ti alloys

增材制造（AM）是指一种新兴的技术，它通过以一层一层的方式控制材料的添加，以生产达到或接近最终形状的物体，从而构建3D物体。钛合金是航空航天和生物医学工业中许多应用的关键。这种材料是增材制造的理想候选材料，因为它固有的高成本与提取相关的众多挑战有关，而且由于它对氧气的高亲和力和加工困难，它的制造复杂。迄今为止，该系统的大部分增材制造工作主要集中在cpTi和Ti-6Al-4V的微结构处理和性能关系上。在这种情况下，这些合金的凝固存在显著的知识差距，当考虑到各自的合金元素对快速凝固的影响时，甚至更少考虑这些相互作用将如何在拓扑优化组件的背景下演变。提出的研究将探讨凝固条件、合金元素含量、凝固晶粒尺寸与演变零件几何形状之间的关系等现象。这些关系将允许开发一种先进的微结构-加工-性能-设计框架，适用于所有钛合金，迄今为止还不存在的工具。该框架将是解决包括合金裂纹在内的所有微观组织控制问题的关键。拥有全球业务组合的美国铝业公司以特定的技术目标进入该项目，以保持其在增材制造领域的竞争力和技术领先地位，并为其客户提供钛合金增材制造的解决方案和新方法。他们设想将这一框架扩展到其他增材制造过程，提高他们在所有增材制造过程中的竞争力。该研究的传播将有助于提高加拿大在美国铝业公司作为供应商的所有行业增材制造技术采用率方面的地位。此外，该项目还将培训一名熟悉am的HQP，他们必须采用这种颠覆性技术

Additive Manufacturing (AM) refers to an emerging class of technologies that build 3D objects by the controlled addition of materials in a layer-by-layer fashion to produce objects at or near their final shape. Ti alloys are key for many applications in the aerospace and biomedical industries. This material is an ideal candidate for AM due to its inherent high cost associated with the numerous challenges related to extraction, and from its complex manufacturing due to its high affinity to oxygen and difficulty in machining. To date, the bulk of the work on AM of this system primarily focused on microstructure-processing and properties relationships on cpTi and Ti-6Al-4V. In this context, a significant knowledge gap on the solidification of these alloys exist, more so when considering the effect of the respective alloying element on the rapid solidification, and even less how these interactions would be evolving in the context of a topology optimised component. The proposed research will explore phenomena such as the relationship between the solidification condition, the alloying element content, the solidified ß grain size and the evolutive part geometries. These relationships will permit the development of an advanced microstructure-processing-properties-design framework applicable to all Ti alloys, tools nonexistent to date. This framework will be key in solving all microstructural control issues, including alloy cracking. Alcoa, with its global portfolio of business, has entered the project with specific technological objectives to maintain their competitiveness and technological leadership in the field of AM, and to provide their customers with solutions and new methodologies for AM of Ti alloys. They envisaged to expend this framework to other AM processes, improving their competitiveness on all AM processes. The dissemination of the research will contribute to improve Canada's position in adoption rate of AM technologies for all industries having Alcoa as supplier. Moreover, this project will train an additional AM-literate HQP, mandatorily needed to adopt this disruptive technology.**