Finish Machining of Additive Manufactured Metals

添加制造(AM)通过在任何需要的地方一层一层地存放/铺设材料来创建几何图形，并且历史上被用作制作用于演示或使用前评估的原型的便捷方法。技术和设备方面的重大进步使AM认识到了为服务应用生产高度定制化部件的能力。因此，最近探索AM的能力和潜在应用的研究项目的数量激增这一趋势也鼓励制造业探索金属，而不是容易沉积的材料，如塑料。然而，AM金属零件广泛应用的主要障碍之一是其固有的逐层性质，即每一层都在前一层上沉积和固化。AM零件的其他问题是表面质量差和缺乏尺寸精度，这些都是许多应用的关键因素。因此，对AM部件进行后处理是为其使用寿命做好准备的必然步骤。后处理AM零件以达到所需的公差主要是通过精加工来实现的。成功的加工在很大程度上取决于被加工材料的特性。机械加工还会改变表面和亚表面的特性，这需要深入研究。 拟议的NSERC DG计划专门关注三个相互关联的领域： AM对AM金属力学行为影响的研究 根据AM金属的力学性能，建立加工AM金属的本构方程和力模型，以预测切削力 AM金属精加工后可达到的表面完整性研究 选择的工艺将是金属粉床熔化(激光束)，作为一种广泛使用的AM技术。重点材料将是钛合金和高温合金(镍基)，它们广泛用于航空航天工业，由于其难以切割的性质，更有可能成为AM的候选材料。 拟议的研究将使制造业能够更好地了解金属零件在AM之后的后处理精加工过程中的预期材料行为它还将使学生能够在与机械加工和添加剂制造有关的关键领域进行培训。这项研究的独家目标使拟议的计划特别独特和专门，因为据我所知，目前还没有关于AM金属零件的后处理精加工的广泛研究。这项研究必将为以后的研究带来新的进展，特别是在后处理精加工的AM金属的质量、完整性和整体性能方面。制造业是加拿大经济的主要驱动力之一；因此，拟议的研究对加拿大经济大有可为。

Additive manufacturing (AM) creates geometries by depositing/spreading material layer-by-layer wherever desired and was historically used as a convenient method to make prototypes for demonstration or pre-use assessment. Significant progress in technology and equipment has resulted in an awareness of the capabilities of AM for producing highly customized parts for service applications. Hence, there has recently been a surge in the number of research projects exploring the capabilities and potential applications of AM. This trend also encouraged the manufacturing industry to explore metals, rather than easy to deposit materials such as plastics. However, one of the major roadblocks toward the wide application of AM metallic parts goes back to their inherent layer-by-layer nature where each layer is deposited and solidified over the previous layer. Other issues with AM parts are poor surface quality and lack of dimensional accuracy, which are critical factors for many applications. Therefore, post processing the AM parts is an inevitable step toward preparing them for their service life. Post processing AM parts to attain the desired tolerances is mainly achieved using finish machining. Successful machining highly depends on the characteristics of material to be machined. Machining also alters the surface and subsurface characteristics, which needs thorough investigation. The proposed NSERC DG program specifically focuses on three interconnected areas: Studying the effect of AM on the mechanical behavior of AM metals Developing a constitutive equation and a force model for machining AM metals to predict the cutting forces based on the mechanical properties of AM metals Investigating the attainable surface integrity after finish machining of AM metals Process of choice will be metal powder bed fusion (laser beam), as a widely used AM technique. Materials of focus will be titanium alloys and superalloys (nickel-based) that are widely used in aerospace industry and are more likely candidates for AM, due to their difficult-to-cut nature. The proposed research will enable the manufacturing industry to have a better understanding of the expected material behavior during the post-process finish machining of metallic parts after AM. It will also enable training of students in key areas pertaining to both machining and additive manufacturing. The exclusive targets of this research make the proposed program particularly unique and specialized due to the fact that, to the best of my knowledge, there has not yet been extensive research pertaining to the post-process finish machining of AM metallic parts. This research will certainly lead to future progress, particularly, concerning the quality, integrity, and overall performance of the AM metals that undergo post-process finish machining. The manufacturing sector serves as one of the main driving forces for Canada's economy; hence, the proposed research holds great promise for the Canadian economy.