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Full-Text Articles in Manufacturing
Construction Of Metallic Glass Structures By Laser-Foil-Printing Technology, Yiyu Shen, Yingqi Li, Hai-Lung Tsai
Construction Of Metallic Glass Structures By Laser-Foil-Printing Technology, Yiyu Shen, Yingqi Li, Hai-Lung Tsai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Metallic glasses (MGs) have superior mechanical properties such as high tensile strength, hardness, and corrosion resistance, as compared to crystalline metals. Although newly developed MGs have significantly reduced critical cooling rates down to 10 K/s, products of MGs are still limited to simple geometries such as foils/plates or rods with thin section-thickness which is mainly caused by the decrease of thermal conductivities of the new MGs. Recently, we developed a new Laser-foil-printing (LFP) additive manufacturing technology which welds foils, layer by layer, to construct desired 3D structures. With the LFP and Zr-based amorphous foils, 3D, large amorphous structures with complex …
Fabricating Zirconia Parts With Organic Support Material By The Ceramic On-Demand Extrusion Process, Wenbin Li, Amir Ghazanfari, Devin Mcmillen, Andrew Scherff, Ming-Chuan Leu, Greg Hilmas
Fabricating Zirconia Parts With Organic Support Material By The Ceramic On-Demand Extrusion Process, Wenbin Li, Amir Ghazanfari, Devin Mcmillen, Andrew Scherff, Ming-Chuan Leu, Greg Hilmas
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Ceramic On-Demand Extrusion (CODE) is an extrusion-based additive manufacturing process recently developed for fabricating dense, functional ceramic components. This paper presents a further development of this process and focuses on fabricating 3 mol% yttria-stabilized zirconia (3YSZ) components that cannot be fabricated without using support structures. The 3YSZ paste is deposited through the main nozzle, and a polycaprolactone (PCL) pellet feedstock is melted and deposited through an auxiliary nozzle to build support structures. After a green part is printed and dried, the support structures are removed by heating the part to ~70 ⁰C to melt the PCL. The part is then …
Dc-Gain Layer-To-Layer Stability Criterion In Laser Metal Deposition Processes, Patrick M. Sammons, Douglas A. Bristow, Robert G. Landers
Dc-Gain Layer-To-Layer Stability Criterion In Laser Metal Deposition Processes, Patrick M. Sammons, Douglas A. Bristow, Robert G. Landers
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In Laser Metal Deposition (LMD), a blown powder metal additive manufacturing process, functional metal parts are fabricated in a layer-by-layer fashion. In addition to the in-layer dynamics, which describe how the process evolves within a given layer, the additive-fabrication property of LMD creates a second set of dynamics which describe how the process evolves from layer-to-layer. While these dynamics, termed layer-to-layer dynamics, are coupled with both the in-layer dynamics and the process operating conditions, they are not widely considered in the modeling, process planning, or process control of LMD operations. Because of this, seemingly valid choices for process parameters can …
Methods Of Extrusion On Demand For High Solids Loading Ceramic Paste In Freeform Extrusion Fabrication, Wenbin Li, Amir Ghazanfari, Ming-Chuan Leu, Robert G. Landers
Methods Of Extrusion On Demand For High Solids Loading Ceramic Paste In Freeform Extrusion Fabrication, Wenbin Li, Amir Ghazanfari, Ming-Chuan Leu, Robert G. Landers
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Fabrication of highly dense parts with complex geometry by paste-extrusion-based solid freeform fabrication processes requires a precise control of the extrusion flow rate to dispense material on demand, which is often referred as Extrusion-On-Demand (EOD). The extrusion process for aqueous ceramic pastes is complex and difficult to control due to their non-Newtonian behavior, compressibility and inhomogeneity. In this study, three methods of EOD (based on ram extruder, needle valve, and auger valve) are introduced and investigated for the extrusion of high solids loading (i.e., > 50%, volumetric) aqueous alumina paste. Optimal extrusion process parameters for these methods are determined through printing …