Mechanical Engineering Commons^™

Design, Fabrication, And Reliability Effects Of Additively Manufactured First Level Compliant Interconnects For Microelectronics Application, Tumininu David Olatunji

Graduate Theses and Dissertations

Semiconductor packaging and development is greatly dependent on the magnitude of interconnect and on-chip stress that ultimately limits the reliability of electronic components. Thermomechanical related strains occur because of the coefficient of thermal expansion mismatch from different conjoined materials being assembled to manufacture a device. To curb the effect of thermal expansion mismatch between conjoined parts, studies have been done in integrating compliant structures between dies, solder balls, and substrates. Initial studies have enabled the design and manufacturing of these structures using a photolithography approach which involves a high number of fabrication steps depending on the complexity of the structures …

Modeling And Analysis For Unit Cell Size, Material Anisotropy And Material Imperfection Effects Of Cellular Structures Fabricated By Powder Bed Fusion Additive Manufacturing., Yan Wu

Electronic Theses and Dissertations

Cellular structures are networks of interconnected struts or walls with porosities and are widely found in many natural load-bearing structures such as plants and bones. Cellular structures offer unique functional characteristics such as high stiffness to weight ratio, tailorable heat transfer coefficient, and enhanced mechanical energy absorption, which makes them highly attractive in various engineering disciplines such as biomedical implants, electrodes, heat exchangers, and lightweight structures. There exists an abundance of literatures that have investigated various mechanical properties of various cellular structures such as Poisson’s ratio, elastic modulus, ultimate strength, yield strength, and failure characteristics. Based on the classic cellular …

Parametric Study Of Residual Stresses In Wire And Arc Additive Manufactured Parts, Hisham Khaled Jamil Abusalma

Mechanical & Aerospace Engineering Theses & Dissertations

Wire and Arc Additive Manufacturing (WAAM) is a cost-effective additive manufacturing process due to its capability to fabricate large metal parts with high deposition rate and low equipment cost. Although this method is gaining popularity in manufacturing industry, more research is needed to understand process parameters’ effects on residual stress (RS) distribution and part distortion. As such, a 3D thermo-elastic-plastic transient model was established in ABAQUS and employed to investigate the effect of process parameters such as the torch speed, the deposition power and the interlayer dwell time on RS distribution and distortion in WAAM part. The numerical model utilized …

Measurement And Analysis Of Pressure Profile For Nozzle Based Single Screw Extrusion Systems, Jake Dvorak

Masters Theses

Most large-scale material-extrusion (MatEx) AM systems utilize a single screw extruder. Simulating flow rate and operating pressures of extrusion systems is notoriously difficult without resorting to full finite element analysis due to the phase change and non-Newtonian nature of relevant polymers. This study characterized two machines of interest: a Big Area Additive Manufacturing (BAAM) system and a Randcastle Microtruder. A custom nozzle adapter was fabricated to gather pressure data within the nozzle and mimic the die design of the BAAM on the Microtruder system. Several theories were tested for overall machine output and max pressure. Feed and compression zone theories …

The Effect Of Compaction Temperature And Pressure On Mechanical Properties Of 3d Printed Short Glass Fiber Composites, Pushpashree Jain Ajith Kumar Jain

Mechanical & Aerospace Engineering Theses & Dissertations

Among many thermoplastics that are used in engineering, polyamide 6 (nylon 6) is an extremely versatile engineering thermoplastic. Nylon filled with glass fibers has higher mechanical strength and high wear resistance than general purpose nylon. 3D printed composites, based on fused filament modeling, typically suffer from poor bead-to-bead bonding and relatively high void content, limiting their mechanical properties

This thesis explores the effect of compaction pressure and temperature on improving the mechanical properties of 3D printed composites. Engineering moduli in the printing and transverse to printing direction, as well as ultimate strength were measured using the tensile testing with Digital …

Laser Powder Bed Fusion Of Nitihf High-Temperature Shape Memory Alloy: Effect Of Process Parameters On The Thermomechanical Behavior, Mohammadreza Nematollahi, Guher P. Toker, Keyvan Safaei, Alejandro Hinojos, S. Ehsan Saghaian, Othmane Benafan, Michael J. Mills, Haluk E. Karaca, Mohammad Elahinia

Mechanical Engineering Faculty Publications

Laser powder bed fusion has been widely investigated for shape memory alloys, primarily NiTi alloys, with the goal of tailoring microstructures and producing complex geometries. However, processing high temperature shape memory alloys (HTSMAs) remains unknown. In our previous study, we showed that it is possible to manufacture NiTiHf HTSMA, as one of the most viable alloys in the aerospace industry, using SLM and investigated the effect of parameters on defect formation. The current study elucidates the effect of process parameters (PPs) on the functionality of this alloy. Shape memory properties and the microstructure of additively manufactured Ni-rich NiTiHf alloys were …

Direct 3d Printing Of Silica Doped Transparent Magnesium Aluminate Spinel Ceramics, John M. Pappas, Xiangyang Dong

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Transparent magnesium aluminate spinel ceramics were additively manufactured via a laser direct deposition method in this study. With a minimum porosity of 0.3% achieved, highly transparent spinel samples with the highest total optical transmittance of 82% at a wavelength of 632.8 nm, were obtained by a 3D printing approach. However, cracking was found to be a major issue affecting printed spinel samples. To control prevalent cracking, the effect of silica dopants was investigated. Increased silica dopants reduced average total crack length by up to 79% and average crack density by up to 71%. However, a high dopant level limited optical …

Modulating Mechanical Properties Of Polymer Composites Via Colloidal Particle Reinforcement, Yusheng Guo

LSU Master's Theses

Additive manufacturing allows the rapid process of complex objects with excellent design flexibility. However, the products often exhibit poor mechanical properties when pure polymer is applied as printable material. In this work, we demonstrate that printability of polymer can be dramatically improved when particle filler is added to form reinforced polymer composites. Furthermore, the interaction between filler and polymer matrix leads to the enhancement in mechanical properties of the printed product. The material reinforcement induced by addition of fillers enables the wide application of polymer composites to print structures with unique features. In the printing of silica-reinforced pNIPAM composite, we …

Open Source High-Temperature Reprap For 3-D Printing Heat-Sterilizable Ppe And Other Applications, Noah G. Skrzypczak, Nagendra G. Tanikella, Joshua M. Pearce

Michigan Tech Publications

Thermal sterilization is generally avoided for 3-D printed components because of the relatively low deformation temperatures for common thermoplastics used for material extrusion-based additive manufacturing. 3-D printing materials required for high-temperature heat sterilizable components for COVID-19 and other applications demands 3-D printers with heated beds, hot ends that can reach higher temperatures than polytetrafluoroethylene (PTFE) hot ends and heated chambers to avoid part warping and delamination. There are several high temperature printers on the market, but their high costs make them inaccessible for full home-based distributed manufacturing required during pandemic lockdowns. To allow for all these requirements to be met …

Laser Metal Deposition Of An Alcocrfeniti₀.₅ High-Entropy Alloy Coating On A Ti6al4v Substrate: Microstructure And Oxidation Behavior, Wenyuan Cui, Wei Li, Wei Ting Chen, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ti6Al4V has been recognized as an attractive material, due to its combination of low density and favorable mechanical properties. However, its insufficient oxidation resistance has limited the high-temperature application. In this work, an AlCoCrFeNiTi_0.5 high-entropy alloy (HEA) coating was fabricated on a Ti6Al4V substrate using laser metal deposition (LMD). The microstructure and isothermal oxidation behaviors were investigated. The microstructure of as-deposited HEA exhibited a Fe, Cr-rich A2 phase and an Al, Ni, Ti-enriched B2 phase. Its hardness was approximately 2.1 times higher than that of the substrate. The oxidation testing at 700⁰C and 800⁰C suggested that the HEA coating …

Understanding The Laser Powder Bed Fusion Of Alsi10mg Alloy, Holden Hyer, Le Zhou, Sharon Park, Guilherme Gottsfritz, George Benson, Bjorn Tolentino, Brandon Mcwilliams, Kyu Cho, Yongho Sohn

Mechanical Engineering Faculty Research and Publications

We examine the microstructural characteristics of LPBF AlSi10Mg produced by using a wide range of LPBF processing parameters with independently varied laser power, hatch spacing, scan speed, slice thickness, and the normalized energy density. The lower energy density produced lack of fusion flaws from residual interparticle spacing, while the higher energy density produced spherical pores from trapped gas. The highest density (> 99%) samples were produced by using an energy density of 32 to 54 J/mm³. Within this energy density range, use of smaller slice thicknesses increased the processing window that would produce dense AlSi10Mg samples. A cellular …

Application Of Optimized Laser Surface Re-Melting Process On Selective Laser Melted 316l Stainless Steel Inclined Parts, Jafar Ghorbani, Jianzhi Li, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications and Presentations

Lower surface quality of selective laser melting (SLM) manufactured parts remains to be a key shortcoming particularly for high performance functional components. In this paper, the authors utilized Box–Behnken methodology to explore the effect of laser surface re-melting process parameters. The process parameters are:laser power, laser exposure time, laser point distance, and shell layer thickness. The experiments were conducted using Renishaw AM-250 machine. SLM manufactured parts with inclination of 45˚ up-skin were treated with a given surface roughness using laser surface re-melting (LSR). The optimization of process parameters was conducted using response surface methodology and the validation tests was carried …

An Investigation Of The Effect Of Contour Process Parameters On The Surface Roughness And Dimensionality Of Overhanging Features In 17-4 Stainless Steel., Katherine Schneidau

Electronic Theses and Dissertations

The relationship between varying contour settings and part geometry provides insight into the attainable surface roughness and dimensional accuracy of parts fabricated in 17-4 stainless steel via selective laser melting (SLM). Varying the contour settings of laser power (W), scan speed (mm/s), and beam offset (mm) for unsupported inclined bars. The utilization of a coordinate measuring machine (CMM) and surface profilometer quantified the dimensional accuracy and average surface roughness (Ra) for upface, downface, and topface surfaces. Adjusting the laser power and scan speed had minimal affect to surface roughness compared to part geometry. Part dimensionality was affected by the …

Experimental Study Of Graphene Energy Absorbing Layer In Femtosecond Infrared Laser Assisted Bioprinting, Chaoran Dou

Theses and Dissertations

The bioprinting, as a new branch of additive manufacturing, already shown its potential in organ transplantation, medicine develop and personalized medicine. There are three types of bioprinting: droplet based bioprinting, extrusion based bioprinting and laser assisted bioprinting (LAB). Compared with other types of bioprinting, the LAB is the only bioprinting method that does not have a nozzle, which gives it the ability to print high viscosity bioink. The LAB also enjoys higher resolution and cell viability than other methods.

The bubble/jet formation process is the most important process for the LAB, which deposits the bioink to the substrate. To utilize …

Additive Manufacturing And Characterization Of Agi And Agi–Al2O3 Composite Electrolytes For Resistive Switching Devices, Benjamin J. Brownlee, Lok-Kun Tsui, Karthik Vempati, John B. Plumley, Brian D. Iverson, Thomas L. Peng, Fernando H. Garzon

Faculty Publications

This work investigates the electrochemical dynamics and performance of additively manufactured composite electrolytes for resistive switching. Devices are comprised of a Ag/AgI–Al₂O₃/Pt stack, where the solid state electrolyte is additively manufactured using extrusion techniques. AgI–Al₂O₃ composite electrolytes are characterized by x-ray diffraction and electrochemical impedance spectroscopy. The ionic conductivities of the electrolytes were measured for different concentrations of Al₂O₃, observing a maximum conductivity of 4.5 times the conductivity of pure AgI for composites with 20 mol. % Al₂O₃. There was little change in activation energy …

Effects Of Zirconia Doping On Additively Manufactured Alumina Ceramics By Laser Direct Deposition, John M. Pappas, Aditya R. Thakur, Xiangyang Dong

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The ability to additively manufacture functional alumina ceramics has the potential to lower manufacturing costs and development time for complex components. In this study, the doping effects of zirconia on laser direct deposited alumina ceramics were investigated. The microstructure of the printed samples was analyzed in terms of grain size and composition distribution. The addition of zirconia was found to accumulate along alumina grain boundaries and resulted in significant grain refinement. The zirconia doping largely reduced crack formation during processing compared to that of pure alumina samples. In the case of 10 wt% zirconia, cracking during deposition was nearly completely …

Open-Source Digitally Replicable Lab-Grade Scales, Benjamin R. Hubbard, Joshua M. Pearce

Michigan Tech Publications

This study provides designs for a low-cost, easily replicable open-source lab-grade digital scale that can be used as a precision balance. The design is such that it can be manufactured for use in most labs throughout the world with open-source RepRap-class material extrusion-based 3-D printers for the mechanical components and readily available open-source electronics including the Arduino Nano. Several versions of the design were fabricated and tested for precision and accuracy for a range of load cells. The results showed the open-source scale was found to be repeatable within 0.05 g with multiple load cells, with even better precision (0.005 …

Conversion Of Self-Contained Breathing Apparatus Mask To Open Source Powered Air-Purifying Particulate Respirator For Fire Fighter Covid-19 Response, Benjamin R. Hubbard, Joshua M. Pearce

Michigan Tech Publications

To assist firefighters and other first responders to use their existing equipment for respiration during the COVID-19 pandemic without using single-use, low-supply, masks, this study outlines an open source kit to convert a 3M-manufactured Scott Safety self-contained breathing apparatus (SCBA) into a powered air-purifying particulate respirator (PAPR). The open source PAPR can be fabricated with a low-cost 3-D printer and widely available components for less than $150, replacing commercial conversion kits saving 85% or full-fledged proprietary PAPRs saving over 90%. The parametric designs allow for adaptation to other core components and can be custom fit specifically to fire-fighter equipment, including …

Effects Of Powder Recycling In Selective Laser Melting, Nina L. Menon

Industrial and Manufacturing Engineering

The following report analyzes 316L stainless steel powder characteristics of new powder and powder that has been used in the selective laser melting process for 40-50 builds. A literature review was done of powder characteristics, different ways flowability can be tested, and effects of recycling other types of metal powders in Additive Manufacturing. Flowability improved over 21 reuses of the titanium alloy Ti-6Al-4V and resulted in stronger printed parts. Flow of S17-4 PH steel powder was measured with a Hall flowmeter and increased significantly over the course of 10 reuses. Heavily recycled (estimated 50 reuses) 316L SS powder and brand …

Design For Additive Manufacturing, Michael Charonnat, Leonardo Franco-Muñoz, Sam Noble, J.P. Purdom

Mechanical Engineering

This document outlines the critical design details and timeline for the Design for Additive Manufacturing Senior Project sponsored by Solar Turbines, Inc. The scope of this project encompasses the redesign of two of Solar Turbine’s cast parts for metal additive manufacturing in order to minimize lead time, cost, and weight. With the overall objective of performing in-depth analysis exploring affordability & feasibility, this redesign process will aid Solar Turbines in expanding their knowledge of Design for Additive Manufacturing principles and enable them to further incorporate the use of additive manufacturing into their production processes. The first part that the team …

Open Source High-Temperature Reprap For 3-D Printing Heat-Sterilizable Ppe And Other Applications, Noah G. Skrzypczak, Nagendra Gautam Tanikella, Joshua M. Pearce

Michigan Tech Publications

Thermal sterilization is generally avoided for 3-D printed components because of the relatively low deformation temperatures for common thermoplastics used for material extrusion-based additive manufacturing. 3-D printing materials required for high-temperature heat sterilizable components for COVID-19 and other applications demands 3-D printers with heated beds, hot ends that can reach higher temperatures than polytetrafluoroethylene (PTFE) hot ends and heated chambers to avoid part warping and delamination. There are several high temperature printers on the market, but their high costs make them inaccessible for full home-based distributed manufacturing required during pandemic lockdowns. To allow for all these requirements to be met …

Design Of Versatile Feedback Control System Components For Selective Laser Sintering, Thomas Chessman

University Scholar Projects

Selective laser sintering (SLS) is an additive manufacturing technique that involves using a laser to fuse powdered material together, layer by layer, in order to create a 3-D product. Despite its numerous benefits over traditional methods of manufacturing, including higher efficiency, versatility, and the ability to process many materials, selective laser sintering suffers from its propensity to generate structural errors during operation.

Feedback control has been shown to improve fabrication quality in other laser-based additive manufacturing techniques when implemented properly. Widespread exploration of applying feedback control in SLS might lead to significant performance improvements in this form of manufacturing.

This …

Parametric Nasopharyngeal Swab For Sampling Covid-19 And Other Respiratory Viruses: Open Source Design, Sla 3-D Printing And Uv Curing System, Nicole Gallup, Adam Pringle, Shane Oberloier, Nagendra Gautam Tanikella, Joshua M. Pearce

Michigan Tech Publications

Access to nasopharyngeal swabs for sampling remain a bottleneck in some regions for COVID19 testing. This study develops a distributed manufacturing solution using only an open source manufacturing tool chain consisting of two types of open source 3-D printing and batch UV curing, and provides a parametric fully free design of a nasopharyngeal swab. The swab was designed using parametric OpenSCAD in two components (a head with engineered break point and various handles), which has several advantages: i) minimizing print time on relatively slow SLA printers, ii) enabling the use of smaller print volume open source SLA printers, iii) reducing …

Experimental And Numerical Study Of Process Parameters Effects Towards Part Quality And Porosity During Powder Bed Additive Manufacturing Processes., Subin Shrestha

Electronic Theses and Dissertations

Powder bed additive manufacturing (PB-AM) process utilizes an electron beam or a laser as a heat source to melt the metallic powder particles. These processes have the capability of freeform fabrication, however certain defects such as porosity, high surface roughness, etc. would hinder its application. It is important to understand the effect of the process parameters and the underlying physical phenomena, which lead to the formation of such defects. In this regard, a three-dimensional (3D) thermo-fluid model is developed to study the effect of beam speed on the surface morphology during powder bed electron beam additive fabrication (PB-EBAF). Besides, the …

Additive Manufacturing Of Dense We43 Mg Alloy By Laser Powder Bed Fusion, Holden Hyer, Le Zhou, George Benson, Brandon Mcwilliams, Kyu Cho, Yongho Sohn

Mechanical Engineering Faculty Research and Publications

WE43 is a high-strength, corrosion-resistant Mg-alloy containing rare earths such as Y and Nb, and has potential for many lightweight structural or bioresorbable prosthetic applications. In this study, additive manufacturing of dense WE43 alloy by laser powder bed fusion (LPBF) from gas atomized powders has been accomplished through studies involving single track scan of wrought WE43, parametric variation of LPBF, microstructural analysis and mechanical testing, both in compression and tension. The Archimedes method and image analyses from optical micrographs were employed to document the LPBF of dense (>99 % relative density) WE43 using optimum parameters of 200 W laser …

Selective Laser Melting 17-4 Ph Stainless Steel And The Effect Of Varied Thermal Treatments On Fatigue Behavior., Sean Daniel Dobson

Electronic Theses and Dissertations

Fatigue failure is the leading source of loss in industry. In order for new means of manufacturing to move towards mainstream use a complete understanding of material and mechanical behavior must be gained. This endeavor seeks to aide in that task by observing the fatigue behavior of selective laser melting (SLM) additive manufacturing (AM) specimens and the effect of differing thermal treatment conditions for an optimized AM process. Stainless steel 17-4 PH specimens were fabricated using SLM AM and thermally treated to three conditions: as-built, solutionized and hardened, and direct hardened. These specimens were characterized for material (powder quality, density, …

Influences Of Material Extrusion Additive Manufacturing (Meam) Parameters And Additives On Polyvinylidene Fluoride (Pvdf) Properties., Niknam Momenzadeh

Electronic Theses and Dissertations

Beyond the beneficial characteristics of smart polymers associated with all polymers such as flexibility and cost fabrication, smart materials exhibit multifunctional behaviors. The prospect of integrating structural and sensing/actuation capabilities into a single structure gives design engineers an ability to innovate highly novel, multi-functional creations. Polyvinylidene Fluoride (PVDF) is one of the widely used multi-functional materials which offers a variety of desirable material properties. It possesses exceptional chemical and UV resistance, biocompatibility, low processing temperature and affordable price making it a competitive choice for many commercial applications. In addition, among polymers, PVDF is simply the most dominant piezoelectric polymer. On …

Impact Of Part Thickness And Drying Conditions On Saturation Limits In Binder Jet Additive Manufacturing, Nathan B. Crane

Faculty Publications

Binder jetting (BJ) is a high build-rate additive manufacturing process with growing commercial interest. Growth in BJ applications is driven by the use of finer powders and improved post-processing methods that can produce dense, homogenous final parts. However, understanding of the basic droplet/powder interaction is relatively limited. This paper considers the impact of in-process drying, part geometry, and droplet size on a key printing parameter: binder saturation. Parts of varying thicknesses are printed with a range of saturation levels under various heating conditions. The ratio of the printed part mass to the theoretical part mass is used to detect bleeding. …

Aluminum Parts Fabricated By Laser-Foil-Printing Additive Manufacturing: Processing, Microstructure, And Mechanical Properties, Chia Hung Hung, Yingqi Li, Austin Sutton, Wei Ting Chen, Xiangtao Gong, Heng Pan, Hai Lung Tsai, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Fabrication of dense aluminum (Al-1100) parts (>99.3% of relative density) by our recently developed laser-foil-printing (LFP) additive manufacturing method was investigated as described in this paper. This was achieved by using a laser energy density of 7.0 MW/cm2 to stabilize the melt pool formation and create sufficient penetration depth with 300 μm thickness foil. The highest yield strength (YS) and ultimate tensile strength (UTS) in the LFP-fabricated samples reached 111 ± 8 MPa and 128 ± 3 MPa, respectively, along the laser scanning direction. These samples exhibited greater tensile strength but less ductility compared to annealed Al-1100 samples. Fractographic …

Synthesis And Advanced Manufacturing Of Polymer Structures And Their Composites, Bethany Rose Wilburn

Open Access Theses & Dissertations

The following research work performed embodies three unique studies of polymer structures and their composites. In general, polymers are viscoelastic, insulative materials that are used for a wide variety of applications within industrial, aerospace, and biomedical fields. Polymers have been studied and optimized for any particular use by chemically synthesizing unique micro-structures, altering the physical properties through fabrication and post-processing, and utilizing 3D printing to achieve complex geometries. In the past decade, additive manufacturing (AM) has drawn extensive attention across academia, industry, and government agencies. It offers unprecedented advantages such as design freedom, rapid prototyping, and customization. In this work, …