Manufacturing Commons^™

Effect Of Sparse-Build Internal Structure On Performance Of Fused Deposition Modeling Tools Under Pressure, S. Meng, L. Mason, Gregory Taylor, X. Wang, Ming-Chuan Leu, K. Chandrashekhara, Mike Matlack, James Castle

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Two different approaches to design a sparse-build tool for fabrication by the fused deposition modeling (FDM) process are compared. One approach uses a 2D lattice structure and the other approach is inspired by topology optimization. Ultem 9085 is used as the material, and the amount of material used to build the tool is kept constant to ensure a fair comparison. A solid tool is also included in the comparison. The performance of the tool under uniform pressure is simulated using finite element analysis (FEA) and the accuracy of the FEA results is verified by comparing them with experimentally measured data …

Effects Of Build Parameters On Compression Properties For Ultem 9085 Parts By Fused Deposition Modeling, Krishna P. Motaparti, Gregory Taylor, Ming-Chuan Leu, K. Chandrashekhara, James Castle, Mike Matlack

Mechanical and Aerospace Engineering Faculty Research & Creative Works

It has been observed by various researchers that parts fabricated by the Fused Deposition Modeling (FDM) process have anisotropic properties. The research presented in the present paper was aimed to study the compression properties of FDM parts and to comprehend their dependence on build parameters. In this study Ultem 9085 was used as the material to fabricate both solid and sparse-build coupons with variations in build direction, raster angle and air gap. A full factorial experimental design was used to study the individual and combined effects of these build parameters on the mechanical properties of the coupons. The mechanical properties …

Novel Extrusion-Based Additive Manufacturing Process For Ceramic Parts, Amir Ghazanfari, Wenbin Li, Ming-Chuan Leu, Greg Hilmas

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An extrusion-based additive manufacturing process, called the Ceramic On-Demand Extrusion (CODE) process, for producing three-dimensional ceramic components with near theoretical density is introduced in this paper. In this process, an aqueous paste of ceramic particles with a very low binder content (< 1 vol%) is extruded through a moving nozzle at room temperature. After a layer is deposited, it is surrounded by oil (to a level just below the top surface of most recent layer) to preclude non-uniform evaporation from the sides. Infrared radiation is then used to partially, and uniformly, dry the just-deposited layer so that the yield stress of the paste increases and the part maintains its shape. The same procedure is repeated for every layer until part fabrication is completed. Several sample parts for various applications were produced using this process and their properties were obtained. The results indicate that the proposed method enables fabrication of large, dense ceramic parts with complex geometries.

Properties Of Partially Stabilized Zirconia Components Fabricated By The Ceramic On-Demand Extrusion Process, Wenbin Li, Amir Ghazanfari, Devin Mcmillen, Ming-Chuan Leu, Greg Hilmas, Jeremy Lee Watts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Ceramic On-Demand Extrusion (CODE) process is a novel additive manufacturing process for fabricating dense ceramic components from aqueous pastes of high solids loading. In this study, 3 mol% Y₂O₃ stabilized tetragonal zirconia polycrystal (3Y-TZP) parts were fabricated using the CODE process. The parts were then dried in a humidity controlled environmental chamber and sintered under atmospheric pressure. Mechanical properties of the sintered parts were examined using ASTM standard test techniques, including density, Young’s modulus, flexural strength, Weibull modulus, fracture toughness and Vickers hardness. The microstructure was analyzed, and grain size was measured using scanning electron microscopy. …

Laser Line Scan Characterization Of Geometric Profiles In Laser Metal Deposition, Michelle L. Gegel, A. Nisbett, Douglas A. Bristow, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser Metal Deposition (LMD) is an additive manufacturing process in which material is deposited by blowing powdered metal into a melt pool formed by a laser beam. When fabricating parts, the substrate is subjected to motion control such that the melt pool traces a prescribed path to form each part layer. Advantages of LMD include relatively efficient powder usage, the ability to create functionally-graded parts and the ability to repair high-value parts. The process, however, is sensitive to variations in process parameters and a need for feedback measurements and closed-loop control has been recognized in the literature [1, 2]. To …

Effect Of Powder Particle Size On The Fabrication Of Ti-6al-4v Using Laser Metal Deposition From Elemental Powder Mixture, Xueyang Chen, Lei Yan, Wei Li, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct Laser Metal Deposition (LMD) was used to fabricate thin-wall Ti-6Al-4V using the powder mixture of Ti-6 wt.%Al-4 wt.%V. Scanning electron microscopy (SEM), optical microscopy (OM) and energy dispersive spectroscopy (EDS) were employed to examine the chemical composition and microstructure of the as-deposited sections. Vickers hardness tests were then applied to characterize the mechanical properties of the deposit samples which were fabricated using pre-mixed elemental powders. The EDS line scans indicated that the chemical composition of the samples was homogenous across the deposit. X-ray diffraction (XRD) was used for the phase identification. After significant analysis, some differences were observed among …

Proposed Hybrid Processes For Part Building Using Fusion Welding And Friction Stir Processing, Megan A. Gegesky, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

It has been shown that a hybrid laser additive manufacturing and friction stir processing can deposit components with forged-like structures. This paper reports a hybrid fusion welding and friction stir process to create parts with quality structures. Combining traditional fusion welding and friction stir processing techniques for non-weldable aluminum alloys could facilitate the joining of difficult geometries in manufactured parts. This research illustrates mechanical property changes for non-weldable and weldable aluminum alloys. The Vickers hardness, and microhardness in the case of AA5052-H32, tensile strength and corrosion resistance of four processing states: base material, fusion welded material, friction stir welded material, …

Powders For Additive Manufacturing Processes: Characterization Techniques And Effects On Part Properties, Austin T. Sutton, Caitlin S. Kriewall, Ming-Chuan Leu, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Powder-bed based Additive Manufacturing is a class of Additive Manufacturing (AM) processes that bond successive layers of powder by laser melting to facilitate the creation of parts with complex geometries. As AM technology transitions from the fabrication of prototypes to end-use parts, the understanding of the powder properties needed to reliably produce parts of acceptable quality becomes critical. Consequently, this has led to the use of powder characterization techniques such as scanning electron microscopy (SEM), laser light diffraction, x-ray photoelectron spectroscopy (XPS), and differential thermal analysis (DTA) to both qualitatively and quantitatively study the effect of powder characteristics on part …

Elevated Temperature Microstructure Stability Of Slm 304l Stainless Steel, Tarak Amine, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

With time at temperature, changes in metallurgical structure can be expected for almost any steel or alloy. In stainless steels, the changes can be grain growth, carbide precipitation, ferrite decomposition, or embrittlement. These phenomena can significantly effect the properties of the steel and would potentially change the functionality of the component. Therefore, to determine component stability, the elevated temperature microstructure stability of additive manufacturing materials was studied. This work investigates the influence of different aging times of additive material stainless steels (304L) fabricated with the Selective Laser Melting (SLM) process on microstructure and mechanical properties. Microstructure and mechanical properties were …

Simulation Of Cooling Rate Effects On Ti-48al-2cr-2nb Crack Formation In Direct Laser Deposition, Lei Yan, Wei Li, Xueyang Chen, Yunlu Zhang, Joseph William Newkirk, Frank W. Liou, David Dietrich

Materials Science and Engineering Faculty Research & Creative Works

Transient temperature history is vital in direct laser deposition (DLD) because it reveals the cooling rate at specific temperatures, which directly relates to phase transformation and types of microstructure formed in deposit. FEA simulation was employed to study the transient temperature history and cooling rate at different experimental setups in Ti-48Al-2Cr-2Nb DLD process. In this paper, an innovative model was described, which combines a moving Gaussian distribution heat source and element birth and death technology in ANSYS, help to analysis cooling rate control method and guide crack-free deposits build process.

A Smooth Toolpath Generation Method For Laser Metal Deposition, Renwei Liu, Zhiyuan Wang, Yunlu Zhang, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser metal deposition (LMD), also known as direct metal deposition (DMD) or laser engineered net shaping (LENS), which uses a laser beam to form a melt pool on a metallic substrate, into which powder or wire is fed. The conventional contour and zigzag toolpath pattern for LMD are discontinuous at turn points or corner points. The discontinuous toolpath causes uneven deposition, which brings height variation and porosity problems. This paper aims to develop a smooth toolpath generation method for LMD to improve the deposition quality. A parametric curve equation based on trigonometric functions is derived and built. It can be …

Modal Response As A Validation Technique For Metal Parts Fabricated With Selective Laser Melting, Joshua D. Pribe, Brian M. West, Michelle L. Gegel, Troy Hartwig, Toby Lunn, Ben Brown, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper investigates modal analysis as a validation technique for additively manufactured parts. The Frequency Response Function (FRF) is dependent on both the geometry and the material properties of the part as well as the presence of any defects. This allows the FRF to serve as a “fingerprint” for a given part of given quality. Once established, the FRF can be used to qualify subsequently printed parts. This approach is particularly attractive for metal parts, due to the lower damping as well as use in high-value applications where failure is unacceptable. To evaluate the efficacy of the technique, tensile specimens …

Integration Of Voxel Based And Source Based Representation For Computer Aided Design Of Functional Gradient Materials, Fangquan Wang, Frank W. Liou, Todd E. Sparks

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Functionally Gradient Materials (FGMs) feature smooth transition from one material to another within a single object. FGMs modeling is considered to be one of the new challenges in Computer Aided Design area. To overcome this challenge, this paper presents the integration of a source-based and voxel-based approach to model FGMs. The input of STL format can be meshed and voxelized. The material composition and material varying information in each voxel can be generated from control sources. In addition, surface source is used to define default material information, and several filtering methods, including Gaussian filter, Average filter, are applied to blend …

Determining The Print Accuracy Of Four Three-Dimensional Printers, Kshiteej Dalal

Master of Technology Management Plan II Graduate Projects

Rapid prototyping [RP] or 3D printing [3DP] have existed for some time now. One of the major deficiencies of 3DP is the accuracy of the printed three dimensional parts. Even beyond that is the lack of studies that have been designed to measure the 3DP components. Measuring, verifying and determining the accuracy of 3DP parts is the focus of this study. As the accuracy is measured and approaches those of CNC machined parts, it will drive the development of additional additive manufacturing [AM] machinery. In this project a component is created in a solid modeling package. A solid model of …

Laser-Assisted Microchanneling On Pmma Substrate Utilizing Two-Pass Fabrication Method, Sijie Zhang, Yung C. Shin

The Summer Undergraduate Research Fellowship (SURF) Symposium

Microchannel is widely used in microfluidic devices for mixing, chemical reaction, detection, particle separation and etc. CO₂ laser-based microchanneling of PMMA as a low cost, rapid, noncontact fabrication method has attracted the attention of industry. However, the typical V-shape grooves fabricated by CO₂ laser microchanneling have limitations since the V-shape grooves will affect the flow behavior and heat transfer of the fluid, which are important to the performance of microfluidic devices. A two-pass fabrication method is proposed and investigated in this paper to improve the quality of the PMMA microchannel fabricated by CO₂ laser. It was found …

Laser Assisted Manufacturing: A Comparison Of Mechanical Properties Between Lam And Conventional Manufacturing Techniques, William Blakeslee, Neil S. Bailey, Kyung-Min Hong, Shunyu Liu, Yung C. Shin

The Summer Undergraduate Research Fellowship (SURF) Symposium

Laser assisted manufacturing methods, such as direct metal deposition (DMD) and laser beam welding (LBW), are promising methods because of their higher precision and greater productivity when compared to traditional manufacturing methods. Because these methods are relatively new, the mechanical properties of samples produced by laser assisted manufacturing are not well understood. In this study the mechanical properties of samples produced by laser assisted manufacturing methods are analyzed and compared with data obtained from traditional manufacturing methods. The DMD process used Fe-TiC and Ti-TiC metal matrix composites, while LBW used AISI 304 stainless steel. The results vary widely with the …

Applications Of Additive Manufacturing Techniques In Making Energetic Materials, Peter A. Cattani, Trevor J. Fleck, Jeff F. Rhoads, Steven F. Son, I. Emre Gunduz

The Summer Undergraduate Research Fellowship (SURF) Symposium

Energetic materials are currently manufactured using methods such as casting, which can only produce certain geometries. Additive manufacturing enables more flexible fabrication and the potential for improved material consistency. Additive manufacturing has transformed many industries, but has only recently been applied to the manufacturing of energetic materials. This paper describes the development of two processes to apply additive manufacturing methods to energetic materials. Method one applies a fused deposition modelling approach (FDM). 5 µm aluminum powder and PVDF were mixed and made into filaments using a Filabot Original filament extruder. Energetic filaments were created composed of 90:10, 80:20, and 75:25 …

Design For Manufacturability: Off-Road Toyota Bumper, Drew Donlon

Industrial and Manufacturing Engineering

The purpose of this project is to design a new off-road bumper that is improved from the stock form of a 1996-2002 Toyota 4Runner and a 1996-2004 Toyota Tacoma. The current state of the component is too weak to endure to off-road endeavors, and a kit bumper market is virtually untapped for these vehicles. The objectives of this project were met by redesigning the stock front bumper, conducting a finite element analysis on the model to test for strength, prototyping the bumper with CNC cut cardboard, and conducting a full cost analysis including the costs for waterjet and laser cutting …

Evolution Of The Automotive Body Coating Process—A Review, Nelson K. Akafuah, Sadegh Poozesh, Ahmad Salaimeh, Gabriela Patrick, Kevin Lawler, Kozo Saito

Mechanical Engineering Faculty Publications

Automotive coatings and the processes used to coat automobile surfaces exemplify the avant-garde of technologies that are capable of producing durable surfaces, exceeding customers’ expectations of appearance, maximizing efficiency, and meeting environmental regulations. These accomplishments are rooted in 100 years of experience, trial-and-error approaches, technique and technology advancements, and theoretical assessments. Because of advancements directed at understanding the how, why, when, and where of automobile coatings, the progress in controlling droplets and their deposition attributes, and the development of new technologies and paint chemistries, a comprehensive and up-to-date review of automobile coatings and coating technologies was considered to be of …

Gold Contamination In Non-Lead Surface Mount Solder Joints, Richard Alexander Garrison

Industrial and Manufacturing Engineering

Abstract

Solder joints are critical to the reliability of circuit boards. If gold is introduced to the solder joint, brittle AuSn4 intermetallic compounds develop which affect reliability of that solder joint. To determine the effects of gold when dissolved into a non-lead solder joint, a process was developed in order to apply gold content onto SAC305 solder paste. The gold was transferred as a paste from a micropipette onto each individual solder bump. This process was designed to apply a range of gold content from 1.0 wt. % to 10 wt. % to each individual solder joint. The test board …