Mechanical Engineering Commons^™

Experimental Measurement Of Residual Stress And Distortion In Additively Manufactured Stainless Steel Components With Various Dimensions, M. Ghasri-Khouzani, H. Peng, R. Rogge, R. Attardo, P. Ostiguy, J. Neidig, R. Billo, D. Hoelzle, M. R. Shankar

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Disk-shaped 316L stainless steel parts with various diameters and heights were additively manufactured using a direct metal laser sintering (DMLS) technique. Neutron diffraction was used to profile the residual stresses in the samples before and after removal of the build plate and support structures. Moreover, distortion level of the parts before and after the removal was quantified using a coordinate measuring machine (CMM). Large tensile in-plane stresses (up to ≈ 400 MPa) were measured near the as-built disk top surfaces, where the stress magnitude decreased from the disk center to the edges. The stress gradient was steeper for the disks …

Distributed Manufacturing Of Flexible Products: Technical Feasibility And Economic Viability, Aubrey Woern, Joshua M. Pearce

Department of Materials Science and Engineering Publications

Distributed manufacturing even at the household level is now well established with the combined use of open source designs and self-replicating rapid prototyper (RepRap) 3-D printers. Previous work has shown substantial economic consumer benefits for producing their own polymer products. Now flexible filaments are available at roughly 3-times the cost of more conventional 3-D printing materials. To provide some insight into the potential for flexible filament to be both technically feasible and economically viable for distributed digital manufacturing at the consumer level this study investigates 20 common flexible household products. The 3-D printed products were quantified by print time, electrical …

Note On The Rate And Energy Efficiency Limits For Additive Manufacturing, Timothy Gutowski, Sheng Jiang, Daniel Cooper, Gero Corman, Michael Hausmann, Jan-Anders Manson, Timo Schudeleit, Konrad Wegener, Matias Sabelle, Jorge Ramos-Grez, Dusan P. Sekulic

Mechanical Engineering Faculty Publications

We review the process rates and energy intensities of various additive processing technologies and focus on recent progress in improving these metrics for laser powder bed fusion processing of metals, and filament and pellet extrusion processing of polymers and composites. Over the last decade, observed progress in raw build rates has been quite substantial, with laser metal processes improving by about 1 order of magnitude, and polymer extrusion processes by more than 2 orders of magnitude. We develop simple heat transfer models that explain these improvements, point to other possible strategies for improvement, and highlight rate limits. We observe a …

Additive Manufacturing Process Of 3d Polyaniline Transducers Via Direct Ink Writing, Frederick Benjamin Holness

Electronic Thesis and Dissertation Repository

Electroactive polymers exhibit a change in properties, typically size or shape, in response to electrical stimuli. One class of electroactive polymer of particular interest are the conjugated polymers, whose conjugated backbone structure imparts electrical conductivity. However, this structure imposes processing limitations restricting their form to 2D structures. To overcome this, we develop specially formulated polyaniline- based blends via counter-ion induced thermal doping for the fabrication of 3D conductive structures via direct ink writing. This approach employs multi-material extrusion for the production of structures with passive and active features, rapid device fabrication, and improved design freedom. A model of the thermal …

Building Zr-Based Metallic Glass Part On Ti-6al-4v Substrate By Laser-Foil-Printing Additive Manufacturing, Yingqi Li, Yiyu Shen, Ming-Chuan Leu, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Through using Zr intermediate layers, Zr_52.5Ti₅Al₁₀Ni_14.6Cu_17.9 metallic glass (MG) parts are successfully built on Ti-6Al-4V substrates by laser-foil-printing (LFP) additive manufacturing technology in which MG foils are laser welded layer-by-layer onto the substrate. The printed MG part is free of porosity, cracking and crystallization; additionally, its glass transition temperature, crystallization temperature, micro-hardness, and tensile strength are very similar to the original MG material. The Zr intermediate layers are aimed at preventing direct interaction between the first layer of MG foil and the Ti substrate; otherwise, the welded MG foils would peel …

Additive Manufacturing Of High Solids Loading Hybrid Rocket Fuel Grains, Stephen P. Johnson, Michael Baier, Ibrahim E. Gunduz, Steven F. Son

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hybrid rocket motors offer many of the benefits of both liquid and solid rocket systems. Like liquid engines, hybrid rocket motors are able to be throttled, can be stopped and restarted, and are safer than solid rocket motors since the fuel and oxidizer are in different physical states. Hybrid rocket motors are similar to solid motors in that they are relatively simple and have a high density-specific impulse. One of the major drawbacks of hybrid rocket motors is a slower burning rate than solid rocket motors. Complex port geometries provide greater burning surface area to compensate for lower burning rates …

Impact Of Diy Home Manufacturing With 3d Printing On The Toy And Game Market, Emily Peterson, Joshua M. Pearce

Department of Materials Science and Engineering Publications

The 2020 toy and game market is projected to be US$135 billion. To determine if 3D printing could affect these markets if consumers offset purchases by 3D printing free designs, this study investigates the 100 most popular downloaded designs at MyMiniFactory in a month. Savings are quantified for using a Lulzbot Mini 3D printer and three filament types: commercial filament, pellet-extruded filament, and post-consumer waste converted to filament with a recyclebot. Case studies probed the quality of: (1) six common complex toys; (2) Lego blocks; and (3) the customizability of open source board games. All filaments analyzed saved the user …

Feasibility Of Using 3d Printed Molds For Thermoforming Thermoplastic Composites, Sunil Bhandari

Electronic Theses and Dissertations

This thesis presents a novel combined experimental and numerical mechanics approach for characterizing 3D printed thermoplastic materials by the fused deposition modeling process for thermoforming thermoplastic composites. The implications of this work are:

1. a methodology for model-based performance evaluation of 3D printed structural parts, and
2. an improved design of 3D printed molds for composites manufacturing, which has potential for material innovations and scaled-up applications in additive manufacturing.

The thesis formulates basic criteria for selection of thermoplastic polymer used for the 3D printed mold based on forming temperatures. The thesis creates a lattice and shell finite element model of the 3D …

The Intersection Of Manufacturing Technologies And School Music Programs, Leslie Prunier

University Scholar Projects

The objective of this project is to design and manufacture a musical instrument, a marching baritone horn, out of plastic. It is constructed out of both PVC pipe and 3D-printed components. Utilizing this project’s documentation, a high school student could use a 3D printer and other basic tools to make their own musical instrument for a fraction of the cost of purchasing one. This documentation will produce a horn tuned in the key of B flat with one functioning valve, and suggestions for future work to make the other two valves functional as well.

Process Parameter Optimization With Numerical Modelling And Experimentation Design Of Binder Jet Additive Manufacturing, Sairam Vangapally

All Graduate Theses, Dissertations, and Other Capstone Projects

Binder jetting technology is an additive manufacturing technology in which powder materials are binded together layer by layer forming the product from input CAD model. The process involves printing the product layer by layer, curing and sintering. The mechanical properties of 3D printed samples varies based on process parameters, hence there is a need to tune the process parameters for optimal characteristics. Three main parameters namely layer thickness, sintering time and sintering temperature were identified and the study focuses on the effect of parameters on dimensional accuracy and compressive strength of the samples. Full factorial experimental approach was used to …

Variable Oxidation & Defects In Ti-6al-4v Material In Electron Beam Melting Additive Manufacturing, Edward Patton Clark

Electronic Theses and Dissertations

Powder-based metal in additive manufacturing (AM) is advantageous for rapid prototyping of parts and components, with the benefit of reusing powder to reduce production costs. A common driver in the aerospace industry is free-form complex geometries which can be created using CAD software to optimize specifications with strength-to-weight ratios in components. Weight optimization of aircraft components using additive manufacturing reduces material, which significantly reduces production cost in comparison to cast and wrought metallic products. Large biomedical and aerospace industries heavily invest in feedstock metal powders that have low density under structural stresses and high temperatures, resulting in superior resistance to …

Process Development And Characterization Of Smart Parts Fabricated Using Powder Bed Fusion Additive Manufacturing Technologies, Mohammad Shojib Hossain

Open Access Theses & Dissertations

The fields of modern energy conversion, e.g., fossil fuel, natural gas, and coal power plants, are in increased need of health monitoring and data collection (temperature, pressure, and flow rate) to improve process efficiency and satisfy the demand for clean energy. In situ process monitoring can lead to a robust automated system to achieve the goal. The monitoring equipment or sensors in energy systems components (e.g., pressure tube, turbine blade, and fuel injector) undergo high temperature, high pressure, and corrosive environments; for example, combustion inlet conditions can reach up to 810 K and 2760 kPa [1]. Therefore, a reliable, accurate, …

Repair Of Metallic Components Using Hybrid Manufacturing, Renwei Liu

Doctoral Dissertations

"Many high-performance metal parts users extend the service of these damaged parts by employing repair technology. Hybrid manufacturing, which includes additive manufacturing (AM) and subtractive manufacturing, provides greater build capability, better accuracy, and surface finish for component repair. However, most repair processes still rely on manual operations, which are not satisfactory in terms of time, cost, reliability, and accuracy. This dissertation aims to improve the application of hybrid manufacturing for repairing metallic components by addressing the following three research topics. The first research topic is to investigate and develop an efficient best-fit and shape adaption algorithm for automating 3D models' …

The Effects Of Fiber Orientation And Volume Fraction Of Fiber On Mechanical Properties Of Additively Manufactured Composite Material, Suresh Chandra Kuchipudi

All Graduate Theses, Dissertations, and Other Capstone Projects

Additive manufacturing (AM) also known as 3D printing has tremendous advancements in recent days with a vast number of applications in industrial, automotive, architecture, consumer projects, fashion, toys, food, art, etc. Composite materials are widely used in structures with weight as a critical factor especially in aerospace industry. Recently, additive manufacturing technology, a rapidly growing innovative technology, has gained lot of importance in making composite materials. The properties of composite materials depend upon the properties of constituent’s matrix and fiber. There is lot of research on effect of fiber orientation on mechanical properties of composite materials made using conventional manufacturing …