The research objective of this award is to establish a microscopic mechanical inhibition theory underlying the metal powder sintering process and to develop the Selective Inhibition Sintering process for fabrication of parts in metals that have high sintering temperature. In the Selective Inhibition Sintering process, an inhibitor agent is used in shaping the part geometry. To understand the scientific principles underlying such a process, systematic study of the inhibition phenomenon will be performed for metals with various sintering temperatures. The relation between inhibition capability and the printed inhibitors including their chemical components, printing parameters and sintering path will be established. Statistically designed experiments will be performed to understand the relations between process parameters and fabrication performances such as fabrication time, part accuracy, resolution, and material properties. A demonstration system will be built for the identification of the key factors for process control and optimization.
If successful, this research will provide a novel additive manufacturing process that can present an order of magnitude reduction in machine cost and an order of magnitude improvement in building speed as compared with other metal-based additive manufacturing processes. Practical uses of such a metallic part fabrication technique will benefit a wide variety of industries including aerospace, defence, automotive, and medical, especially for fabrication of hard-to-machine materials such as stainless steel and titanium. The funded activity will provide educational opportunities for graduate students and for high school students from underprivileged areas around the University of Southern California and Saddleback College. Undergraduate students from Saddleback College will also be intensely involved in experimentation and demonstrations at RapidTech, which is a National Center for Rapid Technologies.