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

金属增材制造（AM）最近在使用和能力方面都有了显着增长，在工业和消费市场的采用率也有所增加。在这一领域，令人望而却步的挑战仍然是技术采用的成本，以及高质量无缺陷零件的可靠生产。为了应对这些挑战，该项目的重点将是：（1）通过采用低成本的水雾化合金钢AISI 4340来部署粉末床粘结剂喷射（PBBJ），从而降低成本壁垒（0.4C-0.7Mn-0.25Si-1.8Ni-0.8Cr-0.25Mo）和FL4401（0.15Mn-0.85Mo）+0.6C和（2）通过建模方法和对所需产品质量结果的稳健验证实现稳健和快速的工艺参数选择。该项目的总体目标是证明通过PBBJ的金属AM可以部署为金属零件生产的低成本和可靠的替代方案，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Rio Tinto公司密切合作进行，该公司是一家从事金属粉末制造的领先金属和采矿公司。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工艺窗口。将研究感兴趣的过程变量，并制造定制设计的工件以测试绿色部件的性能。工艺窗口也将使用新提出的绿色部分密度模型进行预测。第二个包将侧重于后处理参数窗口的开发，从而将研究感兴趣的材料的几个后处理变量，如脱脂和烧结。将通过计算机断层扫描、表面轮廓测量和机械测试分析部件质量。最终部件密度预测模型（烧结曲线）将通过将工艺变量映射到最终部件密度的烧结分析来开发。第三个也是最后一个工作包将侧重于功能产品设计和制造。将开发标准工件，以量化PBBJ特定的设计特征。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.