Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Engineering

A Hybrid Process Integrating Reverse Engineering, Pre-Repair Processing, Additive Manufacturing, And Material Testing For Component Remanufacturing, Xinchang Zhang, Wenyuan Cui, Wei Li, Frank W. Liou Jun 2019

A Hybrid Process Integrating Reverse Engineering, Pre-Repair Processing, Additive Manufacturing, And Material Testing For Component Remanufacturing, Xinchang Zhang, Wenyuan Cui, Wei Li, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Metallic components can gain defects such as dents, cracks, wear, heat checks, deformation, etc., that need to be repaired before reinserting into service for extending the lifespan of these parts. In this study, a hybrid process was developed to integrate reverse engineering, pre-repair processing, additive manufacturing, and material testing for the purpose of part remanufacturing. Worn components with varied defects were scanned using a 3D scanner to recreate the three-dimensional models. Pre-repair processing methods which include pre-repair machining and heat-treatment were introduced. Strategies for pre-repair machining of defects including surface impact damage, surface superficial damage and cracking were presented. Pre-repair ...


Freeform Extrusion Fabrication Of Advanced Ceramics And Ceramic-Based Composites, Wenbin Li Jan 2019

Freeform Extrusion Fabrication Of Advanced Ceramics And Ceramic-Based Composites, Wenbin Li

Doctoral Dissertations

"Ceramic On-Demand Extrusion (CODE) is a recently developed freeform extrusion fabrication process for producing dense ceramic components from single and multiple constituents. In this process, aqueous paste of ceramic particles with a very low binder content ( < 1 vol%) is extruded through a moving nozzle to print each layer sequentially. Once one layer is printed, it is surrounded by oil to prevent undesirable water evaporation from the perimeters of the part. The oil level is regulated just below the topmost layer of the part being fabricated. Infrared radiation is then applied to uniformly and partially dry the top layer so that the yield stress of the paste increases to avoid part deformation. By repeating the above steps, the part is printed in a layer-wise fashion, followed by post-processing. Paste extrusion precision of different extrusion mechanisms was compared and analyzed, with an auger extruder determined to be the most suitable paste extruder for the CODE system. A novel fabrication system was developed based on a motion gantry, auger extruders, and peripheral devices. Sample specimens were then produced from 3 mol% yttria stabilized zirconia using this fabrication system, and their properties, including density, flexural strength, Young's modulus, Weibull modulus, fracture toughness, and hardness were measured. The results indicated that superior mechanical properties were achieved by the CODE process among all the additive manufacturing processes. Further development was made on the CODE process to fabricate ceramic components that have external/internal features such as overhangs by using fugitive support material. Finally, ceramic composites with functionally graded materials (FGMs) were fabricated by the CODE process using a dynamic mixing device"--Abstract, page iv.


Development Of Test Methods For Characterizing Extrudability Of Cement-Based Materials For Use In 3d Printing, Jonathan Thomas Kuchem Jan 2019

Development Of Test Methods For Characterizing Extrudability Of Cement-Based Materials For Use In 3d Printing, Jonathan Thomas Kuchem

Masters Theses

"3D printing is the process of creating three-dimensional objects using an automated additive manufacturing process. The 3D printing process has been used with materials such as metals and polymers, but application with cement based materials for the construction industry has yet to be developed. In this research, two main problems were investigated for printing cement based composite materials: extrudability and tensile reinforcement. Fiber-reinforced concrete (FRC) was studied as an internal reinforcing system to increase tensile/flexural strength. First, FRC was studied to investigate mechanical properties and use of fibers from waste tires as an environmentally friendly option. A reference mixture ...