SUBJECT: Ph.D. Proposal Presentation
BY: Jinqiang Ning
TIME: Tuesday, July 24, 2018, 3:00 p.m.
PLACE: MRDC Building, 4404
TITLE: Analytical Modeling of Material Constitutive Behaviors and Process Mechanics in Precision Machining and Additive Manufacturing
COMMITTEE: Dr. Steven Y. Liang, Chair (ME)
Dr. Thomas Kurfess (ME)
Dr. Shreyes N. Melkote (ME)
Dr. Ting Zhu (ME)
Dr. Hamid Garmestani (MSE)


Materials constitutive behaviors and process mechanics are important components in the fundamental understanding of precision machining and additive manufacturing. Analytical modeling of material constitutive behaviors using process mechanics is needed to improve quality of the produced part and efficiency of the process. Ultra-fine-grained titanium (UFG Ti) and Ti-6Al-4V alloy are chosen to investigate the machining process and additive manufacturing process respectively. UFG Ti is increasingly finding usefulness in lightweight applications and in medical implant field because of its sufficient mechanical strength, manufacturability, and high biocompatibility with human tissues. Ti-6Al-4V alloy is one of the titanium alloys widely used in aerospace industry and biomechanical applications because of its high strength, light weight, and excellent corrosion resistance. Currently, the fundamental knowledge in machining UFG Ti and in additive manufacturing is not fully provided. Physics-based analytical models in predicting the machining process and the additive manufacturing process are not readily available.
The objectives of this proposed study are 1) to improve the fundamental understanding of material constitutive behaviors and process mechanics in precision machining and metal-based additive manufacturing, and 2) to develop physics-based analytical models using process mechanics and constitutive relations to predict material constitutive behaviors in precision machining and metal-based additive manufacturing. The objectives will be achieved with analytical and experimental studied. Force, temperature, and residual stress in machining UFG Ti will be predicted using analytical models. Distortion in the additive manufacturing using gas atomized Ti-6Al-4V powder and selective laser melting technique will be predicted with analytical models considering scanning strategy, powder size distribution, printing layer effect, edge effect. Analytical models will be validated by comparing to experimental measurements.
The fundamental knowledge and analytical models can be utilized to further investigate the processing technology, processing efficiency, and the quality of manufactured part in machining and metal-based additive manufacturing.