Developing new metallic alloys for Additive Manufacturing

加拿大制造业占国内生产总值的10%和近10%的劳动力（加拿大统计局）。增材制造（AM）或3D打印是一种新的制造方法，其中三维组件逐层构建，形成复杂的3D部件。这种制造方法与传统制造方法有很大不同。通常，设计和铸造部件，然后进行热加工和冷加工，热处理和机加工。AM为重新设计组件提供了创新的新机会。AM正在经历一个戏剧性的增长，在2017年扩大超过21.5亿美元，行业整体增长21%。必须开发新的金属合金，以满足迄今认为不可能制造的部件的创新设计的特殊需要。 创新的设计包括在增材制造组件中使用桁架网格。这使得能够使用具有尚未用于工程应用的新型成分的粉末合金。铝-铜合金（Al-Cu）是一个例子，其中传统上由于轻量化目标和增加的强度，铜含量被限制在~4.5wt%。随着用于AM的桁架设计的出现，可以使用更高铜含量的合金，同时生产具有比传统整体材料更轻的密度并且具有相当大的强度增加的部件。建议开始这一计划的研究Al-Cu和Al-Ni的共晶和近共晶成分。最初感兴趣的是形成共晶的工艺条件。随后，将研究通过时效使共晶的金属间组分球化的能力。然后，这些粉末将与Mech E UofA的Qureshi教授合作用于AM设备。这将刺激工业和NSERC资助的新项目，使用这些新型粉末制造AM组件。将使用扫描电子显微镜、中子散射和3D显微断层扫描对共晶显微结构进行定量表征。球形金属间化合物的演化将按照Ho和韦瑟利的定义。将使用定量图像分析和机器学习技术测量金属间化合物颗粒之间的间距及其尺寸。最后，这些测量将与老化样品的维氏显微硬度测量有关。4名研究生将在5年内接受培训。两个将处理铝铜和两个铝镍。一组两名学生将解决该项目的快速凝固方面，而其他两个将解决粉末的老化处理。这将为所有4名学生提供高温实验，表征方法，3D显微断层扫描，定量金相学以及合金凝固路径建模以及凝固发展的微观结构和所得性能之间的关系的培训。这一建议中所描述的努力为我们的研究提供了新的动力。

Canadian manufacturing accounts for 10% of GDP and nearly 10% of the labour force (Statistics Canada). Additive manufacturing (AM), or 3D printing, is a new manufacturing approach where three dimensional components are built layer by layer forming a complex 3D part. This manufacturing approach deviates significantly from traditional manufacturing. Typically, components are designed and cast followed by hot and cold working, heat treatment and machining. AM provides innovative new opportunities for re-designing components. AM is undergoing a dramatic rise expanding in 2017 by more than $2.15 billion and a 21% overall growth in the industry. New metallic alloys must be developed to meet the special needs for innovative designs of components hitherto thought impossible to make. Innovative designs include the use of truss lattices in AM components. This enables the use of powdered alloys with novel compositions not yet used for engineering applications. Aluminum-copper alloys (Al-Cu) is one example, where traditionally the copper content is limited to ~4.5wt% due to light-weighting goals and increased strength. With the advent of truss designs for AM, higher copper content alloys may be utilised while producing components with lighter densities than traditional monolithic materials and with a considerable increase in strength. It is proposed to begin this program by studying Al-Cu and Al-Ni of eutectic and near-eutectic compositions. Of initial interest is the process conditions under which eutectics form. Subsequently, the ability to spheroidize the intermetallic constituent of the eutectic by aging will be studied. The powders will then be used in AM equipment in collaboration with Prof Qureshi, Mech E UofA. This will stimulate new projects funded by industry and NSERC using these novel powders in making AM components. The eutectic microstructures will be quantitatively characterized using scanning electron microscopy, neutron scattering and 3D micro-tomography. The evolution of spherical intermetallics will be defined following Ho and Weatherly. The spacing between intermetallic particles and their size will be measured using quantitative image analysis and machine learning techniques. Finally, these measurements will be related to Vickers micro hardness measurements to be made on aged samples. Four graduate students will be trained over the duration of 5 years. Two will tackle Al-Cu and two Al-Ni. One set of two students will address the rapid solidification aspects of the project while the other two will address the ageing processing of the powders. This will provide all 4 students training in the conduct of high temperature experiments, characterisation methods, 3D microtomography, quantitative metallography as well as modelling of solidification paths of alloys and the relationship between solidification-developed microstructure and resulting properties. The effort described in this proposal initiates a new thrust in our research.