A Two-Dimensional Simulation Of Grain Structure Growth Within Substrate And Fusion Zone During Direct Metal Deposition,
2017
Missouri University of Science and Technology
A Two-Dimensional Simulation Of Grain Structure Growth Within Substrate And Fusion Zone During Direct Metal Deposition, Jingwei Zhang, Wei Li, Frank W. Liou, Joseph William Newkirk
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In this paper, a predictive model based on a cellular automaton (CA)-finite element (FE) method has been developed to simulate thermal history and microstructure evolution during metal solidification for a laser-based additive manufacturing process. The macroscopic FE calculation that is validated by thermocouple experiment is designed to update the temperature field and a high cooling rate. A cellular automata-finite element (CAFE) method is developed to describe grain growth in the fusion zone. In the mesoscopic CA model, heterogeneous nucleation sites, grain growth orientation and rate, epitaxial growth, remelting of preexisting grains, metal addition, grain competitive growth, and columnar to equiaxed …
Design And Fabrication Of Functionally Graded Material From Ti To Γ-Tial By Laser Metal Deposition,
2017
Missouri University of Science and Technology
Design And Fabrication Of Functionally Graded Material From Ti To Γ-Tial By Laser Metal Deposition, Xueyang Chen, Lei Yan, Joseph William Newkirk, Frank W. Liou
Materials Science and Engineering Faculty Research & Creative Works
Functionally graded material (FGM) is one kind of advanced material characterized by a gradual change in properties as the position varies. The spatial variation of compositional and microstructure over volume is aimed to control corresponding functional properties. In this research, when 100% γ-TiAl was directly deposited on pure Ti substrate, cracks were formed within the γ-TiAl layer. Then a six-layer crack-free functionally graded material of Ti/TiAl was designed and fabricated by laser metal deposition (LMD) method, with composition changing from pure Ti on one side to 100% γ-TiAl on the other side. The fabricated FGM was characterized for material properties …
Mechanical Properties Of 304l Parts Made By Laser-Foil-Printing Technology,
2017
Missouri University of Science and Technology
Mechanical Properties Of 304l Parts Made By Laser-Foil-Printing Technology, Chia-Hung Hung, Yiyu Shen, Ming-Chuan Leu, Hai-Lung Tsai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Laser-Foil-Printing (LFP) is a novel laminated object manufacturing process for metal additive manufacturing. It fabricates three-dimensional metal parts by using a dual-laser system to weld and cut metal foils layer by layer. A main advantage of LFP is the higher cooling rate compared to powder-based laser additive manufacturing processes due to the thermal conductivity difference between foil and powder. This study focuses on the mechanical properties of 304L stainless steel parts built by the LFP process. The experimental results indicate that the yield strength and ultimate tensile strength of LFP fabricated 304L SS parts are higher by 9% and 8% …
Construction Of Metallic Glass Structures By Laser-Foil-Printing Technology,
2017
Missouri University of Science and Technology
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 …
Effects Of Area Fraction And Part Spacing On Degradation Of 304l Stainless Steel Powder In Selective Laser Melting,
2017
Missouri University of Science and Technology
Effects Of Area Fraction And Part Spacing On Degradation Of 304l Stainless Steel Powder In Selective Laser Melting, Cairlin S. Kriewall, Austin T. Sutton, Sreekar Karnati, Joseph William Newkirk, Ming-Chuan Leu
Materials Science and Engineering Faculty Research & Creative Works
In selective laser melting (SLM) systems, a large portion of powder remains unconsolidated and therefore recycling powder could make SLM more economical. Currently, a lack of literature exists specifically targeted at studying the reusability of powder. Furthermore, the definition of powder reusability is complex since powder degradation depends on many factors. The goal of the current research is to investigate the effects of area fraction and part spacing on the degradation of 304L powder in SLM. An experimental study was conducted where various area fractions and part distances were chosen and powder characterization techniques for determination of particle size distributions, …
Aluminum Matrix Syntactic Foam Fabricated With Additive Manufacturing,
2017
Missouri University of Science and Technology
Aluminum Matrix Syntactic Foam Fabricated With Additive Manufacturing, M. Spratt, Joseph William Newkirk, K. Chandrashekhara
Materials Science and Engineering Faculty Research & Creative Works
Syntactic foams are lightweight structural composites with hollow reinforcing particles embedded in a soft matrix. These materials have applications in transportation, packaging, and armor due to properties such as relatively high specific stiffness, acoustic dampening, and impact absorption. Aluminum matrices are the most widely studied of metal matrix syntactic foams, but there is little to no research in regards to processing the foams with additive manufacturing. It is theorized that the fast cooling rates and limited kinetic energy input of additive could reduce two issues commonly associated with processing syntactic foams: microsphere flotation in the melt and microsphere fracture during …
Effect Of Optimizing Particle Size In Laser Metal Deposition With Blown Pre-Mixed Powders,
2017
Missouri University of Science and Technology
Effect Of Optimizing Particle Size In Laser Metal Deposition With Blown Pre-Mixed Powders, Wei Li, Jingwei Zhang, Xinchang Zhang, Sreekar Karnati, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Functionally Graded Material (FGM) is often fabricated by Laser metal deposition with pre-mixed multiple powders (PMM-powder). Since the supplied PMM-powder directly affects FGM’s composition, investigation on PMM-powder’s property is greatly needed. This paper employed experimental method to observe an important problem: PMM-powder separation in fabricating FGM. A novel particle size optimization method was introduced as solution to eliminate the powder separation. Pre-mixed pure Cu and 4047 Al powders were used to do two experiments. The first experiment result disclosed the existence of powder separation. By optimizing the particle size, the PMM-powder separation was effectively solved in the second experiment result.
Studying Chromium And Nickel Equivalency To Identify Viable Additive Manufacturing Stainless Steel Chemistries,
2017
Missouri University of Science and Technology
Studying Chromium And Nickel Equivalency To Identify Viable Additive Manufacturing Stainless Steel Chemistries, Zachary T. Hilton, Joseph William Newkirk, Ronald J. O'Malley
Materials Science and Engineering Faculty Research & Creative Works
Chromium and nickel equivalency modeling has long been used in welding to determine the weldability of steel chemistries. A study was conducted to determine the applicability of Cr-Ni modeling to the additive manufacturing process. Many AM methods involve rapid solidification of small melt pools, similar to welding. Chemistries with varying Cr/Ni ratios were selected for use in a selective laser melting process and modeled using known models. Initial results indicate that the standard "safe welding zone" may not directly apply to additive manufacturing. The capability to build with chemistries outside the weldability “safe zone” could result in improved and varied …
Additive Manufacturing Of High Solids Loading Hybrid Rocket Fuel Grains,
2017
Olivet Nazarene University
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 …
Optimization And Control Of Production Of Graphene,
2017
Purdue University
Optimization And Control Of Production Of Graphene, Atharva Hans, Nimish M. Awalgaonkar, Majed Alrefae, Ilias Bilionis, Timothy S. Fisher
The Summer Undergraduate Research Fellowship (SURF) Symposium
Graphene is a 2-dimensional element of high practical importance. Despite its exceptional properties, graphene’s real applications in industrial or commercial products have been limited. There are many methods to produce graphene, but none has been successful in commercializing its production. Roll-to-roll plasma chemical vapor deposition (CVD) is used to manufacture graphene at large scale. In this research, we present a Bayesian linear regression model to predict the roll-to-roll plasma system’s electrode voltage and current; given a particular set of inputs. The inputs of the plasma system are power, pressure and concentration of gases; hydrogen, methane, oxygen, nitrogen and argon. This …
Impact Of Diy Home Manufacturing With 3d Printing On The Toy And Game Market,
2017
Michigan Technological University
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 …
Maximizing Operating Room Performance Using Portfolio Selection,
2017
University of Kentucky
Maximizing Operating Room Performance Using Portfolio Selection, Vivek Reddy Gunna, Amin Abedini, Wei Li
Mechanical Engineering Faculty Publications
The operating room (OR) is responsible for most hospital admissions and is one of the most cost and work intensive areas in the hospital. From recent trends, we observe an ironic parallel increase among expenditure and waiting time. Therefore, improving OR scheduling has become obligatory, particularly in terms of patient flow and benefit. Most of the hospitals rely on average patient arrivals and processing times in OR planning. But in practice, variations in arrivals and processing times causes high instability in OR performance. Our model of optimization provides OR schedules maximizing patient flow and benefit at a fixed level of …
An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process,
2017
University of Kentucky
An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye
Mechanical Engineering Faculty Publications
Operating room (OR) scheduling is important. Because of increasing demand for surgical services, hospitals must provide high quality care more efficiently with limited resources. When constructing the OR schedule, it is necessary to consider the availability of downstream resources, such as intensive care unit (ICU) and post anaesthesia care unit (PACU). The unavailability of downstream resources causes blockings between every two consecutive stages. In this paper we address the master surgical schedule (MSS) problem in order to minimize blockings between two consecutive stages. First, we present a blocking minimization (BM) model for the MSS by using integer programming, based on …
Three Hundred And Sixty Degree Real-Time Monitoring Of 3-D Printing Using Computer Analysis Of Two Camera Views,
2017
Michigan Technological University
Three Hundred And Sixty Degree Real-Time Monitoring Of 3-D Printing Using Computer Analysis Of Two Camera Views, Siranee Nuchitprasitchai, Michael C. Roggemann, Joshua M. Pearce
Department of Materials Science and Engineering Publications
Prosumer (producing consumer)-based desktop additive manufacturing has been enabled by the recent radical reduction in 3-D printer capital costs created by the open-source release of the self-replicating rapid prototype (RepRap). To continue this success, there have been some efforts to improve reliability, which are either too expensive or lacked automation. A promising method to improve reliability is to use computer vision, although the success rates are still too low for widespread use. To overcome these challenges an open source low-cost reliable real-time optimal monitoring platform for 3-D printing from double cameras is presented here. This error detection system is implemented …
Free And Open Source 3-D Model Customizer For Websites To Democratize Design With Openscad,
2017
Michigan Technological University
Free And Open Source 3-D Model Customizer For Websites To Democratize Design With Openscad, Yuenyong Nilsiam, Joshua M. Pearce
Department of Materials Science and Engineering Publications
3-D printing has entered the consumer market because of recent radical price declines. Consumers can save substantial money by offsetting purchases with DIY pre-designed 3-D printed products. However, even more value can be obtained with distributed manufacturing using mass customization. Unfortunately, the average consumer is not technically sophisticated enough to easily design their own products. One solution to this is the use of an overlay on OpenSCAD parametric code, although current solutions force users to relinquish all rights to their own designs. There is thus a substantial need in the open source design community for a libre 3-D model customizer, …
Energy Payback Time Of A Solar Photovoltaic Powered Waste Plastic Recyclebot System,
2017
Michigan Technological University
Energy Payback Time Of A Solar Photovoltaic Powered Waste Plastic Recyclebot System, Shan Zhong, Pratiksha Rakhe, Joshua M. Pearce
Department of Materials Science and Engineering Publications
The growth of both plastic consumption and prosumer 3-D printing are driving an interest in producing 3-D printer filaments from waste plastic. This study quantifies the embodied energy of a vertical DC solar photovoltaic (PV) powered recyclebot based on life cycle energy analysis and compares it to horizontal AC recyclebots, conventional recycling, and the production of a virgin 3-D printer filament. The energy payback time (EPBT) is calculated using the embodied energy of the materials making up the recyclebot itself and is found to be about five days for the extrusion of a poly lactic acid (PLA) filament or 2.5 …
Open Source Multi-Head 3d Printer For Polymer-Metal Composite Component Manufacturing,
2017
Michigan Technological University
Open Source Multi-Head 3d Printer For Polymer-Metal Composite Component Manufacturing, J. Laureto, Joshua M. Pearce
Department of Materials Science and Engineering Publications
As low-cost desktop 3D printing is now dominated by free and open source self-replicating rapid prototype (RepRap) derivatives, there is an intense interest in extending the scope of potential applications to manufacturing. This study describes a manufacturing technology that enables a constrained set of polymer-metal composite components. This paper provides (1) free and open source hardware and (2) software for printing systems that achieves metal wire embedment into a polymer matrix 3D-printed part via a novel weaving and wrapping method using (3) OpenSCAD and parametric coding for customized g-code commands. Composite parts are evaluated from the technical viability of manufacturing …
Multi-Criteria Flow-Shop Scheduling Optimization,
2017
California Polytechnic State University, San Luis Obispo
Multi-Criteria Flow-Shop Scheduling Optimization, Raviteja Arikati
Industrial and Manufacturing Engineering
A flow-shop is a type of manufacturing job shop where similar jobs follow a similar, linear sequence through the shop. Every day, flow-shops receive several different orders and it is up to the scheduler to plan the daily schedule. This schedule should be designed to prevent bottlenecks in the shop, to have on-time delivery of products, and satisfy several other requirements. Often, schedulers perform subjective scheduling and utilize simple heuristics or just intuition to schedule the jobs. With computer-based scheduling, schedulers can now create schedules and determine quantitatively what sorts of schedules work best. Currently, much of the computer-based schedules …
Yeager Multi-Function Tool Ql+,
2017
California Polytechnic State University, San Luis Obispo
Yeager Multi-Function Tool Ql+, Osiel Flores-Hernandez, Carter Wilson, David Wright, Mitchell Jackson
Industrial and Manufacturing Engineering
No abstract provided.
Polar Coordinate Farm Bot Final Project Report,
2017
California Polytechnic State University, San Luis Obispo
Polar Coordinate Farm Bot Final Project Report, John Brown, Kasenia Colombo, Lucas Salem, Ning Jeng, Rory Stothers, Sam Lees
Industrial and Manufacturing Engineering
FarmBot Inc. is a local startup that is advancing precision agriculture through automation and open source technology. The original FarmBot model, FarmBot Genesis, operates over a rectangular area of 3 x 1.5 meters. It plants, waters, weeds and grows produce autonomously using CNC technology. Our project sponsor and inventor of FarmBot, Rory Aronson, tasked our team with developing and testing a polar coordinate farmbot capable of performing on par with the Cartesian farmbot in growing a circular vegetable garden in a user’s backyard. A successful project was defined by meeting specific customer requirements and engineering specifications predetermined and discussed with …
