Design of novel crack-resistant aluminium alloys for additive manufacturing

制造业对加拿大经济至关重要，占国内生产总值的10%，创造了170万个就业岗位。加法制造(AM)是一种革命性的制造方法，在这种方法中，材料一次打印一层，以生产旨在实现最佳性能的部件，这些部件不容易通过传统工艺生产。尽管有潜在的好处，但由于可打印材料的范围有限和打印材料的质量较差，只有不到10%的加拿大制造商使用金属AM。例如，许多用于结构应用的高强度铝合金在印刷时会开裂。因此，这项研究计划的长期愿景是消除使用金属AM的科学障碍，以促进更具竞争力和可持续发展的加拿大制造业。在接下来的五年里，我的目标是通过了解合金成分、AM加工条件、材料微观结构和机械性能(如强度、塑性)之间的关系，开发适合AM的抗裂、高强度铝合金。我的研究将集中在：(I)通过成分修改来消除商用铝合金中的裂纹，(Ii)通过探索新的成分空间来设计性能超过商业合金的新型铝合金，(Iii)通过评估杂质元素(例如铁)对裂纹和机械性能的影响来开发可回收等级的高强度铝合金，以及(Iv)开发一种工具来标准化AM中的裂纹测量热力学模拟将通过预测合金成分对凝固和裂纹行为的影响来指导合金设计研究。具有定制成分的样品将通过激光金属沉积(一种金属AM)进行打印，并将使用先进的表征方法来阐明导致裂纹消除和强度提高的机制。我的研究将为加拿大制造商带来竞争优势，使他们能够根据需要打印来自高强度、轻质铝合金的定制设计的高质量部件，从而降低开发成本和上市时间。将铝合金的AM应用于运输部门，将导致制造用于车辆轻量化的超轻部件，这有可能减少温室气体排放。这项研究还将通过为AM开发可回收级铝合金原材料来实现更可持续的制造业，这种原材料生产初级铝合金所需的能源较少。我将在研究计划内培训9名高素质人员(HQP)，增加加拿大制造商采用金属AM所需的高技能劳动力的供应。HQP将开发必要的科学知识和技术技能(例如，流程优化、AM设计)，以将知识转化和实施给行业最终用户。

The manufacturing sector is critical to the Canadian economy, accounting for 10% of the GDP and 1.7 million jobs. Additive manufacturing (AM) is a revolutionary approach to manufacturing, in which materials are `printed' one layer at a time to create parts that are designed for optimal performance and that cannot be easily produced by traditional processes. Despite the potential benefits, less than 10% of Canadian manufacturers use metal AM, due to a limited scope of printable materials and poor quality of printed material. For example, many high strength aluminum (Al) alloys used for structural applications crack when they are printed. Therefore, the long-term vision of this research program is to eliminate scientific barriers to the use of metal AM to foster a more competitive and sustainable Canadian manufacturing sector. Over the next five years, I aim to develop crack resistant, high strength Al alloys suitable for AM by understanding the relationships between alloy composition, AM processing conditions, material microstructure, and the mechanical properties (e.g. strength, ductility). My research will focus on: (i) eliminating cracking in commercially available Al alloys through composition modifications, (ii) designing novel Al alloys with properties surpassing those of commercial alloys by exploring new composition spaces, (iii) developing recycling-grade high strength Al alloys by evaluating the effect of impurity elements (e.g. iron) on cracking and mechanical properties, and (iv) developing a tool to standardize crack measurements in AM. Thermodynamic simulations will guide the alloy design research by predicting the effect of alloy composition on the solidification and cracking behaviour. Samples with tailored compositions will be printed by laser metal deposition, a type of metal AM, and advanced characterization methods will be used to elucidate the mechanisms leading to crack elimination and strength improvement. My research will lead to competitive advantages for Canadian manufacturers by allowing them to print high quality parts with customized designs from high strength, lightweight Al alloys on demand, reducing development costs and time to market. Applied to the transportation sector, AM of Al alloys will lead to the creation of ultralightweight parts for vehicle lightweighting, which has the potential to reduce greenhouse gas emissions. The research will also lead to a more sustainable manufacturing sector by developing recycling-grade Al alloy raw materials for AM, which require less energy to produce that primary Al alloys. I will train 9 highly qualified personnel (HQP) within the research program, increasing the supply of highly skilled labour that is necessary to the adoption of metal AM by Canadian manufacturers. HQP will develop the scientific knowledge and technical skills (e.g. process optimization, design for AM) necessary for knowledge translation and implementation to industry end users.