Mechanical properties of thin wall specimens produced by additive manufacturing methods

增材制造（AM）技术为加拿大的经济和社会带来了新的机遇。它可以促进许多部门的坚固，轻质产品的生产，包括航空航天和生物医学，并允许使用以前的制造技术无法实现的设计。 铝和钛合金对AM非常感兴趣，因为这些是相对昂贵的金属，AM可以最大限度地减少传统铸造，锻造和机加工路线产生的材料浪费。 关于薄壁的具体问题，随着截面尺寸减小，表面敏感性，即，表面光洁度对性能的影响更大。此外，由于小的特征尺寸，薄壁经受来自周围粉末床的更显著的热耗散。因此，由AM工艺产生的薄特征通常包括缺陷，诸如未熔化的粉末夹杂物、内部空隙、裂纹和形状不规则性。 表面后AM处理技术通过去除和/或平滑表面，或诱导期望的表面形态或降低拉伸表面残余应力，来解决与不规则形态和完工AM材料表面上随机定位的特征相关联的问题。 因此，该合作伙伴关系的目标是了解粉末特性和AM工艺变量以及AM构建后处理对具有薄壁尺寸的部件的增材制造（AM）的影响，最终目标是能够为通过激光粉末床熔融（L-PBF）和粘合剂喷射工艺制造的这种AM构建设计具有最理想特性的粉末。由于该项目将由2名博士执行。学生，另一个主要成果将是增加上午在魁北克和加拿大的技术基础。 该项目是麦吉尔大学、粉末制造公司A P和C与加拿大高分辨率3D打印机、金属3D零件制造商Nanogrande的合作，也是第一家采用金属粉末纳米增材制造技术的公司。 这三个项目已经有了很强的合作，这个项目将很容易建立在这个基础上。

Additive manufacturing (AM) technology opens new opportunities for the economy and society of Canada. It can facilitate the production of strong, light-weight products for many sectors, including aerospace and biomedical, and it allows designs that were not possible with previous manufacturing techniques. Aluminum and titanium alloys are of great interest for AM since these are relatively expensive metals and AM can minimize the waste of material that is generated by traditional casting, forging and machining routes. Regarding the specific problem of thin walls, as section size decreases, surface sensitivity, i.e., surface finish, is much more influential on the properties In addition, due to the small feature dimensions, the thin walls are subjected to more significant thermal dissipation from the surrounding powder beds. As a result, thin features generated by AM processes often include defects such as un-melted powder inclusions, internal voids, cracks, and shape irregularities. Surface post-AM-processing techniques tackle the issues associated with the irregular morphology and the randomly positioned features on the surface of as-built AM material, by removing and/or smoothing the surface, or inducing a desired surface morphology or reducing the tensile surface residual stress. The goal of this partnership is therefore to understand the effect of powder characteristics and AM process variables and post AM build treatments on the additive manufacturing (AM) of components with thin wall dimensions, the ultimate goal being to be able to design powders with the most desirable characteristics for such AM builds made by laser- powder bed fusion (L-PBF) and binder jet processes. Since this project will be performed by 2 Ph.D. students, another major outcome will be to increase the AM technological base in Quebec and Canada. The project is a collaboration between McGill University, A P and C, a powder manufacturing company, and Nanogrande, a Canadian based manufacturer of high-resolution 3D printers, metal 3D parts and the first with nano additive manufacturing technology with metal powders. All three already enjoy strong collaborations and this project will readily build on this foundation.