Process maps and models for binder jetting additive manufacturing of low cost alloys

金属添加剂制造(AM)最近在用途和能力方面都有了显著的增长，工业和消费市场的采用率也越来越高。这一领域令人望而却步的挑战仍然是技术采用的成本，以及高质量无缺陷部件的可靠生产。为了应对这些挑战，项目的重点将放在(1)通过使用低成本水雾化合金钢AISI 4340(0.4C-0.7Mn-0.25Si-1.8Ni-0.8Cr-0.25Mo)和FL4401(0.15Mn-0.85Mo)+0.6C部署粉末床粘结剂喷射(PBBJ)来降低成本壁垒，以及(2)通过建模方法实现稳健快速的工艺参数选择，并对预期的产品质量结果进行稳健的验证。该项目的总体目标是证明通过PBBJ的金属AM可以作为金属部件生产的低成本和可靠的替代方案部署，并直接应用于备件市场和汽车行业。这项研究将与加拿大QC的力拓密切合作进行，力拓是一家领先的金属和矿业公司，涉及金属粉末的制造。实现拟议目标的方法将是部署三个工作包。首先，将通过实验设计(DoE)程序开发PBBJ过程窗口。将研究感兴趣的工艺变量，并将制造定制设计的人工制品以测试绿色部件的性能。还将使用新提出的绿色零件密度模型来预测工艺窗口。第二个包将侧重于后处理参数窗口的开发，其中将研究感兴趣的材料的几个后处理变量，如脱粘和烧结。零件质量将通过计算机断层扫描、表面轮廓测量和机械测试进行分析。最终的零件密度预测模型(烧结体曲线)将通过膨胀分析得到，该模型将工艺变量映射到最终的零件密度。第三个也是最后一个工作方案将侧重于功能性产品的设计和制造。将开发标准文物，以量化特定于PBBJ的设计特征。一系列汽车和工业产品设计将被制造和测试。

Metal additive manufacturing (AM) has recently seen a significant growth in both use and capabilities, with an increased adoption in industrial and consumer markets. The prohibitive challenges in this space remain cost of technology adoption, as well as the reliable production of high quality defect-free parts. To tackle these challenges, the project focus will be on (1) lowering the cost barriers by deploying powder bed binder jetting (PBBJ) using low cost water atomized alloy steels AISI 4340 (0.4C-0.7Mn-0.25Si-1.8Ni-0.8Cr-0.25Mo) and FL4401 (0.15Mn-0.85Mo) +0.6C and (2) enabling robust and fast process parameter selection via modeling approaches and robust validation for desired product quality outcomes. The overall objective of the project is to demonstrate that metal AM via PBBJ can be deployed as a low-cost and reliable alternative to metal part production with a direct application to the spare parts market and automotive industry. This study will be conducted in close collaboration with Rio Tinto, QC, Canada, a leading metals and mining company involved in the manufacture of metal powders. The methodology to achieve the proposed objective will be to deploy three work packages. Firstly, a PBBJ process window will be developed through a design of experiments (DoE) procedure. The process variables of interest will be studied, and custom designed artifacts will be manufactured to test green part performance. The process window will also be predicted using newly-proposed green part density models. The second package will focus on post-process parameter window development, whereby several post-process variables such as de-binding and sintering will be studied for the materials of interest. Part quality will be analyzed via computed tomography scans, surface profilometry and mechanical testing. A final part density predictive model (sinter curve) will be developed through dilatometry analysis that will map process variables to final part density. The third and final work package will focus on functional product design and manufacturing. Standard artifacts will be developed to quantify design features specific to PBBJ. A series of automotive and industrial product designs will be fabricated and tested.