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Full-Text Articles in Materials Science and Engineering

Development Of Bragg Fiber Sensor For Corrosion Detection, Cai Hui Tan Aug 2020

Development Of Bragg Fiber Sensor For Corrosion Detection, Cai Hui Tan

Student Works (2020-2029)

Steel corrosion has posed one of the major structural defects in the civil society today. Conventional methods for corrosion monitoring involve high maintenance cost and destructive methods with low accuracy. Recently, Fiber Bragg gratings (FBG) sensor with its high sensitivity in measuring strain and temperature have been widely studied and used in structural health monitoring (SHM). A non-destructive corrosion detection approach based on FBG sensors was developed and tested to monitor corrosion in this research work. The principle of FBG sensing is based on Bragg wavelength shifts that from the corrosion process that induced strain on the FBG due to …


Alumina Ceramic Membrane Incorporated With Graphene Oxide Frameworks For Protein Recovery, Ishak Noor Fauziyah Aug 2020

Alumina Ceramic Membrane Incorporated With Graphene Oxide Frameworks For Protein Recovery, Ishak Noor Fauziyah

Student Works (2020-2029)

Alumina ceramic membrane is undergoing rapid development and innovation for protein recovery process. However, the limitation of this membrane type is membrane fouling due to the deposition and adsorption of proteins on the surface and pore walls of the membranes. It is crucial to minimize membrane fouling by reducing interactions between protein and the membrane surface via surface modification technique. Thus, the main objective of this research is to develop an alumina membrane with enhanced antifouling property for protein recovery process. An alumina dope consisting of 57 wt.% alumina loading was used to fabricate two alumina membrane configurations; which are …


Microstructural Evolution And Mechanical Properties Of Ultra-Fine Grained Tubular Components Processed By Severe Plastic Deformation, Mesbah Mohsen Aug 2020

Microstructural Evolution And Mechanical Properties Of Ultra-Fine Grained Tubular Components Processed By Severe Plastic Deformation, Mesbah Mohsen

Student Works (2020-2029)

The lightweight alloys have been widely used in various engineering applications such as automotive, aerospace, construction, and biomedical industries due to their low densities, high ductility, formability, and facile machining. However, the emerging trend for materials with high mechanical strength and plasticity hampers the widespread application of these alloys. Over the last two decades, severe plastic deformation (SPD) has been introduced as a promising approach for enhancement of the mechanical performance of the lightweight alloys through microstructural manipulations and grain refinement. However, the SPD techniques have been extensively utilized for the fabrication of non-tubular geometries and the studies on the …


Mechanism Of Compaction With Wrinkle Formation During Automatic Stitching Of Dry Fabrics And The Size Effect Of Compression Molded Discontinuous Fiber-Reinforced Composites, Anibal Benjamin Beltran Laredo Aug 2020

Mechanism Of Compaction With Wrinkle Formation During Automatic Stitching Of Dry Fabrics And The Size Effect Of Compression Molded Discontinuous Fiber-Reinforced Composites, Anibal Benjamin Beltran Laredo

Mechanical & Aerospace Engineering Theses & Dissertations

With an ever-increasing demand for composites, more ways of manufacturing them are becoming popular and widely used. Stitching of dry fabrics is an efficient method for improving delamination resistance. Discontinuous fiber reinforced composites can be used as a lightweight alternative material for metals through a process of compression molding, which allows for complex shape manufacturing while offering structural grade mechanical properties.

This study demonstrates how the stitching of dry fabrics can be adapted to more complex surfaces. The consequences of stitching of curvilinear surfaces can result in defect formation. Therefore, to understand the physical formation of possible defects, experimental characterization …


Physical Behavior Of Thermally Affected Bronze And Brass, Samiul Kaiser, Mohammad Salim Kaiser Jul 2020

Physical Behavior Of Thermally Affected Bronze And Brass, Samiul Kaiser, Mohammad Salim Kaiser

Journal of Mechanical Engineering Science and Technology (JMEST)

The physical behavior of thermally affected cast copper, aluminum bronze and brass has been studied by subjecting to heating isochronally for one hour at a range of 600°C. It shows that solid-solution hardening takes place into the Al added bronze and Zn added brass metal. Due to heating Al forms hard and brittle intermetallic of copper aluminates into the bronze metal which responses some age-hardening effects. The electrical conductivity of the metals increases initially through heat treatment due to stress relieving and finally decreases due to formation of intermetallic precipitates. The color of the heated samples are also studied through …


The Influence Of The Reference Area Of Aileron On The N2xx Aircraft Using Computational Fluid Dynamics, Siti Nur Rahmah, Gaguk Jatisukamto, Hary Sutjahjono Jul 2020

The Influence Of The Reference Area Of Aileron On The N2xx Aircraft Using Computational Fluid Dynamics, Siti Nur Rahmah, Gaguk Jatisukamto, Hary Sutjahjono

Journal of Mechanical Engineering Science and Technology (JMEST)

Aileron is a control surface that functions as a regulator of roll motion. The movements of the ailerons are opposite to the left and right sides. Previous studies have shown that graphs of hinge moment coefficient (Chm) values increases with increasing angle of attack. This study is to determine the aerodynamic characteristics of aileron by combining the surface area of the vane into the aileron by varying the aileron’s deflection. The calculation is performed using a numerical method in two dimensions (2D) commercial CFD simulation software. The results of the study concluded that the hinge moment coefficient for modified airfoil …


Hardness Evaluation On Ss 316l Joined With Gas Tungsten Arc Welding Under Constant Heat Treatment, Duwi Leksono, Imam Sudjono Jul 2020

Hardness Evaluation On Ss 316l Joined With Gas Tungsten Arc Welding Under Constant Heat Treatment, Duwi Leksono, Imam Sudjono

Journal of Mechanical Engineering Science and Technology (JMEST)

The purpose of this study is to show the hardness of the GTAW welding results on SS 316L metal with surface heating during the welding process. Observations in this study used SS 316L material with heat temperature regulation on the metal surface of the welding process using heating variations of 100 ℃, 120 ℃ and 140 ℃. The welding process of SS 316L material used a welding joint model uses single V-type welding joint with an angle of 60°, a spacing of 2 mm, a root surface of 1 mm and a thickness of 5 mm. Vickers hardness test was …


The Effect Of Heat Treatment To The Erosion Rate Of Brass Composite, Aminnudin Aminnudin, Solichin Solichin Jul 2020

The Effect Of Heat Treatment To The Erosion Rate Of Brass Composite, Aminnudin Aminnudin, Solichin Solichin

Journal of Mechanical Engineering Science and Technology (JMEST)

Brass composites can be improved their mechanical properties by the heat treatment process. The improvement of the mechanical properties of this technique is expected to increase the resistance of the composite to erosion that occurs in the environment of flow water. Brass composites used are compositeswith fly ash 5, 10, 15, and 20%. The heat treatment process was carried out using electric furnace withoutprotective gas. Composite heat up to 350°C and 400°C for 30 min. and quenching with water. Before and after the erosion test, the weight of the test specimen was weighed with analytical scales. The treatment process affects …


Performance Enhancement Of Shell And Tube Heat Exchanger On Parallel Flow With Single Segmental Baffle, Avita Ayu Permanasari, Poppy Puspitasari, Sukarni Sukarni, Retno Wulandari Jul 2020

Performance Enhancement Of Shell And Tube Heat Exchanger On Parallel Flow With Single Segmental Baffle, Avita Ayu Permanasari, Poppy Puspitasari, Sukarni Sukarni, Retno Wulandari

Journal of Mechanical Engineering Science and Technology (JMEST)

The shell and tube heat exchanger was a tool to exchange the heat energy between fluids with different temperatures that occurred through direct or indirect contact. The energy exchange in fluids could be occurred with the same phase (liquid to liquid or gas to gas) or two fluids with different phase. To date, the process of heat transfer in the industrial field was crucial in machine work. Therefore, there were studies directed to optimize and develop the function and thermal performance of a heat exchanger by adding Baffles to the side of the shell. Vortex flow that occurs with the …


The Effect Of Solution Treatment Temperature And Quenching Media Variation In Heat Treatment Process Cu-Zn-Al Shape Memory Alloys On Shape Memory Effect And Microstructures, Wikan Jatimurti, Monica Gayatri K, Mavindra Ramadhani, Rochman Rochiem Jul 2020

The Effect Of Solution Treatment Temperature And Quenching Media Variation In Heat Treatment Process Cu-Zn-Al Shape Memory Alloys On Shape Memory Effect And Microstructures, Wikan Jatimurti, Monica Gayatri K, Mavindra Ramadhani, Rochman Rochiem

Journal of Mechanical Engineering Science and Technology (JMEST)

Shape memory alloys (SMAs) are metal alloys with a reversible ability to recover their shape at a certain temperature after being deformed. This ability referred to as Shape Memory Effect (SME). The application of SMAs such as Ni-Ti and Cu-Zn-Al alloys usually used on automotive, biomedical, etc. The commonly used SMA is Ni-Ti because of its superior SME properties than Cu-Zn-Al, even though the price is quite higher. The SME of Cu-Zn-Al might be improved by increasing the presence of the martensite phase in its microstructure by heat treatment. The heat treatment process given to Cu-21Zn-5Al alloy is a homogenizing, …


Wavelength Decomposition Of Hybrid Additive Manufacturing Power Signals And Their Relationship With Surface Integrity, Xingtao Wang Jul 2020

Wavelength Decomposition Of Hybrid Additive Manufacturing Power Signals And Their Relationship With Surface Integrity, Xingtao Wang

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Additive Manufacturing (AM) has been a promising manufacturing technology in industrial applications and gained a massive amount of attention from researchers all over the world. Directed Energy Deposition (DED) is an AM process in which focused thermal energy is used to fuse materials by melting as they are deposited. One of the most significant challenges involved in current metal AM processes is improving repeatability and consistency. Substantial effort has already been invested in this area of research.

In this dissertation, a milling tool not only played a role in subtractive manufacturing but also acted as a method of monitoring the …


Protein And Polysaccharide-Based Fiber Materials Generated From Ionic Liquids: A Review., Christopher R Gough, Ashley Rivera-Galletti, Darrel A Cowan, David Salas-De La Cruz, Xiao Hu Jul 2020

Protein And Polysaccharide-Based Fiber Materials Generated From Ionic Liquids: A Review., Christopher R Gough, Ashley Rivera-Galletti, Darrel A Cowan, David Salas-De La Cruz, Xiao Hu

College of Science & Mathematics Departmental Research

Natural biomacromolecules such as structural proteins and polysaccharides are composed of the basic building blocks of life: amino acids and carbohydrates. Understanding their molecular structure, self-assembly and interaction in solvents such as ionic liquids (ILs) is critical for unleashing a flora of new materials, revolutionizing the way we fabricate multi-structural and multi-functional systems with tunable physicochemical properties. Ionic liquids are superior to organic solvents because they do not produce unwanted by-products and are considered green substitutes because of their reusability. In addition, they will significantly improve the miscibility of biopolymers with other materials while maintaining the mechanical properties of the …


Methods Of Uncertainty Quantification For Physical Parameters, Kellin Rumsey Jul 2020

Methods Of Uncertainty Quantification For Physical Parameters, Kellin Rumsey

Mathematics & Statistics ETDs

Uncertainty Quantification (UQ) is an umbrella term referring to a broad class of methods which typically involve the combination of computational modeling, experimental data and expert knowledge to study a physical system. A parameter, in the usual statistical sense, is said to be physical if it has a meaningful interpretation with respect to the physical system. Physical parameters can be viewed as inherent properties of a physical process and have a corresponding true value. Statistical inference for physical parameters is a challenging problem in UQ due to the inadequacy of the computer model. In this thesis, we provide a comprehensive …


Nanohybrid Membrane Synthesis With Phosphorene Nanoparticles: A Study Of The Addition, Stability And Toxicity, Joyner Eke, Philip Alexander Mills, Jacob Ryan Page, Garrison P. Wright, Olga V. Tsyusko, Isabel C. Escobar Jul 2020

Nanohybrid Membrane Synthesis With Phosphorene Nanoparticles: A Study Of The Addition, Stability And Toxicity, Joyner Eke, Philip Alexander Mills, Jacob Ryan Page, Garrison P. Wright, Olga V. Tsyusko, Isabel C. Escobar

Center of Membrane Sciences Faculty Publications

Phosphorene is a promising candidate as a membrane material additive because of its inherent photocatalytic properties and electrical conductance which can help reduce fouling and improve membrane properties. The main objective of this study was to characterize structural and morphologic changes arising from the addition of phosphorene to polymeric membranes. Here, phosphorene was physically incorporated into a blend of polysulfone (PSf) and sulfonated poly ether ether ketone (SPEEK) doping solution. Protein and dye rejection studies were carried out to determine the permeability and selectivity of the membranes. Since loss of material additives during filtration processes is a challenge, the stability …


Synthesis, Self-Assembly And High-Pressure Properties Of Nanoparticles And Hybrid Nanocomposites, Lingyao Meng Jul 2020

Synthesis, Self-Assembly And High-Pressure Properties Of Nanoparticles And Hybrid Nanocomposites, Lingyao Meng

Nanoscience and Microsystems ETDs

Nanoparticles have gained significant scientific interests owing to their unique structural dimensions, size- and shape-tunable properties, and numerous fascinating applications, from opto-electronics, sensor devices, to energy, environmental, and medical fields. Furthermore, the synergistic integration of other materials, including organic polymers, with nanoparticles provides new opportunities and strategies to obtain nanocomposites with superior properties and functionalities. While there is already significant research on the synthesis and characterizations of nanoparticles and hybrid nanocomposites, some research questions, such as how to design and control the interfacial morphology in polymer/nanoparticle hybrid nanocomposites, how to synthesize metal- organic framework (MOF) nanoparticles in well-defined and uniform …


High‐Tensile Strength, Composite Bijels Through Microfluidic Twisting, S. P. Kharal, Robert P. Hesketh, Martin F. Haase Jul 2020

High‐Tensile Strength, Composite Bijels Through Microfluidic Twisting, S. P. Kharal, Robert P. Hesketh, Martin F. Haase

Henry M. Rowan College of Engineering Departmental Research

Rope making is a millennia old technique to collectively assemble numerous weak filaments into flexible and high tensile strength bundles. However, delicate soft matter fibers lack the robustness to be twisted into bundles by means of mechanical rope making tools. Here, weak microfibers with tensile strengths of a few kilopascals are combined into ropes via microfluidic twisting. This is demonstrated for recently introduced fibers made of bicontinuous interfacially jammed emulsion gels (bijels). Bijels show promising applications in use as membranes, microreactors, energy and healthcare materials, but their low tensile strength make reinforcement strategies imperative. Hydrodynamic twisting allows to produce continuous …


Tacky Elastomers To Enable Tear-Resistant And Autonomous Self-Healing Semiconductor Composites, Song Zhang, Yu-Hsuan Cheng, Luke Galuska, Anirban Roy, Matthias Lorenz, Beibei Chen, Shaochuan Luo, Yen-Ting Li, Chih-Chien Hung, Zhiyuan Qian, Peter Blake Joseph St. Onge, Gage T. Mason, Lewis Cowen, Dongshan Zhou, Sergei I. Nazarenko, Robson F. Storey, Bob C. Schroeder, Simon Rondeau-Gagné, Yu-Cheng Chiu, Xiaodan Gu Jul 2020

Tacky Elastomers To Enable Tear-Resistant And Autonomous Self-Healing Semiconductor Composites, Song Zhang, Yu-Hsuan Cheng, Luke Galuska, Anirban Roy, Matthias Lorenz, Beibei Chen, Shaochuan Luo, Yen-Ting Li, Chih-Chien Hung, Zhiyuan Qian, Peter Blake Joseph St. Onge, Gage T. Mason, Lewis Cowen, Dongshan Zhou, Sergei I. Nazarenko, Robson F. Storey, Bob C. Schroeder, Simon Rondeau-Gagné, Yu-Cheng Chiu, Xiaodan Gu

Faculty Publications

Mechanical failure of π-conjugated polymer thin films is unavoidable under cyclic loading conditions, due to intrinsic defects and poor resistance to crack propagation. Here, the first tear-resistant and room-temperature self-healable semiconducting composite is presented, consisting of conjugated polymers and butyl rubber elastomers. This new composite displays both a record-low elastic modulus (


A Spatially Distributed Fiber-Optic Temperature Sensor For Applications In The Steel Industry, Muhammad Roman, Damilola Balogun, Yiyang Zuang, Rex E. Gerald Ii, Laura Bartlett, Ronald J. O'Malley, Jie Huang Jul 2020

A Spatially Distributed Fiber-Optic Temperature Sensor For Applications In The Steel Industry, Muhammad Roman, Damilola Balogun, Yiyang Zuang, Rex E. Gerald Ii, Laura Bartlett, Ronald J. O'Malley, Jie Huang

Materials Science and Engineering Faculty Research & Creative Works

This paper presents a spatially distributed fiber-optic sensor system designed for demanding applications, like temperature measurements in the steel industry. The sensor system employed optical frequency domain reflectometry (OFDR) to interrogate Rayleigh backscattering signals in single-mode optical fibers. Temperature measurements employing the OFDR system were compared with conventional thermocouple measurements, accentuating the spatially distributed sensing capability of the fiber-optic system. Experiments were designed and conducted to test the spatial thermal mapping capability of the fiber-optic temperature measurement system. Experimental simulations provided evidence that the optical fiber system could resolve closely spaced temperature features, due to the high spatial resolution and …


International Year Of Glass, Bill Fahrenholtz Jul 2020

International Year Of Glass, Bill Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.


Synthesis Of Carbide Ceramics Via Reduction And Carburization Of Oxyanions Adsorbed Onto An Activated Carbon Matrix, Grant Wallace Jul 2020

Synthesis Of Carbide Ceramics Via Reduction And Carburization Of Oxyanions Adsorbed Onto An Activated Carbon Matrix, Grant Wallace

Graduate Theses & Non-Theses

Carbide ceramics rank high among the hardest and most chemically resistant materials. Their ability to resist physical and chemical attack under conditions where more traditional materials fail make them very desirable for a number of industrial applications. Their use is limited, however, due to the expensive and energy-intensive methods required to produce them commercially.

A more versatile and energy-efficient process for commercial carbide production has been developed by synthesizing micron/sub-micron carbide ceramic particles through the adsorption and subsequent carburization of anions on an activated carbon matrix. Oxyanion solutions containing sodium tungstate, sodium molybdate, or sodium metasilicate are adsorbed onto activated …


Predicting Effective Fracture Toughness Of Zrb₂-Based Ultra-High Temperature Ceramics By Phase-Field Modeling, Arezoo Emdadi, Jeremy Lee Watts, William Fahrenholtz, Greg Hilmas, Mohsen Asle Zaeem Jul 2020

Predicting Effective Fracture Toughness Of Zrb₂-Based Ultra-High Temperature Ceramics By Phase-Field Modeling, Arezoo Emdadi, Jeremy Lee Watts, William Fahrenholtz, Greg Hilmas, Mohsen Asle Zaeem

Materials Science and Engineering Faculty Research & Creative Works

The effective fracture toughness (EFT) of ZrB2-C ceramics with different engineered microarchitectures was numerically evaluated by phase-field modeling. To verify the model, fibrous monoliths (elongated hexagonal ZrB2-rich cells in a continuous C-rich matrix) with different volume fractions of a C-rich phase were considered. Architectures containing 10 and 30 vol% of C-rich phase showed EFT values about 42% more than that of pure ZrB2. Increasing the C-rich phase to 50 vol%, dropped toughness significantly, which is in agreement with the experimental results. Replacing hexagonal cells with cylindrical, triangular, or square cells of the same cross-sectional …


Prediction Of Isotropic Strain Hardening Material Properties Using Gradient Boosted Regression Tree Method And Hyperparameter Optimization, Darren R. Promer Jul 2020

Prediction Of Isotropic Strain Hardening Material Properties Using Gradient Boosted Regression Tree Method And Hyperparameter Optimization, Darren R. Promer

Masters Theses

In this study a new technique is proposed for the determination of elastic-plastic stress-strain relations for isotropic materials using the force-displacement output from an instrumented indentation test, finite element simulation, and machine learning methods. This non-destructive testing methodology has promising potential for industry implementation. Applications to benefit from this method include the characterization of localized material properties on surface engineered components, and the post-manufacturing assessment of material properties for items such as additively manufactured metallic components and load-bearing welded joints.

Currently, the capability of the instrumented indentation test for determining material properties is limited to the elastic modulus and surface …


A Multiscale Thermomechanical Metal Additive Manufacturing Simulation And The Impact Of Geometry On Residual Stress And Distortion, Luis Fernando Silva Velasco Jul 2020

A Multiscale Thermomechanical Metal Additive Manufacturing Simulation And The Impact Of Geometry On Residual Stress And Distortion, Luis Fernando Silva Velasco

Masters Theses

Metal additive manufacturing is an enabling technology for the rapid prototyping and manufacturing of geometrically complex parts that would otherwise be difficult or impossible to manufacture. However, the manufacturing process can produce undesired residual stresses and distortions. The first part of the work describes the implementation of a multiscale, thermo-mechanical simulation modeling the metal powder bed fusion additive manufacturing process. NASA’s Micromechanics Analysis Code was is to incorporate the microscale effects of an evolving material porosity on the predicted macroscale residual fields. The simulation shows that modeling an evolving material porosity, as the material transitions from a metal powder to …


Piezoresistive Hybrid Nanocomposites For Strain And Damage Sensing: Experimental And Numerical Analysis, Audrey Jean-Miche Gbaguidi Jul 2020

Piezoresistive Hybrid Nanocomposites For Strain And Damage Sensing: Experimental And Numerical Analysis, Audrey Jean-Miche Gbaguidi

Doctoral Dissertations and Master's Theses

Carbon nanomaterials such as carbon nanotubes (CNTs) and graphite nanoplatelets (GNPs) demonstrate remarkable electrical and mechanical properties, which suggest promising structural and functional applications as fillers for polymer nanocomposites.

The piezoresistive behavior of these nanocomposites makes them ideal for sensing applications. Besides, hybrid nanocomposites with multiple fillers like carbon nanotubes (CNTs) and graphite nanoplatelets (GNPs) are known to exhibit improved electrical and mechanical performance when compared to mono-filler composites.

To comprehensively understand the mechanisms of electrical percolation, conductivity, and piezoresistivity in hybrid nanocomposites, the author develops a two-dimensional (2D) and a three-dimensional (3D) computational Monte Carlo percolation network models for …


Precipitate Characterization In Model Al-Zn-Mg-(Cu) Alloys Using Small-Angle X-Ray Scattering, Daniel Freiberg, Wenhui Zhu, Jun Sang Park, Jonathan D. Almer, Paul Sanders Jul 2020

Precipitate Characterization In Model Al-Zn-Mg-(Cu) Alloys Using Small-Angle X-Ray Scattering, Daniel Freiberg, Wenhui Zhu, Jun Sang Park, Jonathan D. Almer, Paul Sanders

Michigan Tech Publications, Part 1

Model 7000 series alloys with and without copper were fabricated into sheets to study precipitation hardening behavior under isothermal aging conditions. Samples of each alloy were subjected to 3 h annealing treatments at various temperatures to produce a range of precipitate size distributions. Hardness, electrical conductivity, and small-angle X-ray scattering (SAXS) were used to characterize the aging behavior of the two alloys. Precipitate size distributions were modeled from the scattering curves for each annealing condition using a maximum entropy method (MEM) and compared to select transmission electron microscopy (TEM) results. The measured average precipitate diameters from TEM were in good …


Preventing Delayed Cracks In Sus304 Deep Drawn Cups Using Extreme Blank Holding Forces Aided By Nanolubrication, Ibrahim Muhammad Shafiq Jul 2020

Preventing Delayed Cracks In Sus304 Deep Drawn Cups Using Extreme Blank Holding Forces Aided By Nanolubrication, Ibrahim Muhammad Shafiq

Student Works (2020-2029)

This study was to investigate the formation and reformation of delayed cracks of SUS304 cylindrical drawn cups under elevated blank holding force (BHF) from 8~32 kN with 1~3 wt% SiO2 nanolubricants concentrations. The widest crack-free BHF range i.e. from 29 ~ 31 kN was determined for 2 wt% of SiO2 in the experiment. Delayed cracks were also observed below and beyond this BHF range. There was an increment of frictional force at the cup flange region when entering the crack-free BHF range, as proven by the rebound in sidewall thickness, relative intensity of α′-martensite, elongated height and drawing force beyond …


Microstructural Characteristics And Mechanical Properties Of Sn-Ag-Cu Solders With Minor Additions Of Al And Zn, Yee Mei Leong Jul 2020

Microstructural Characteristics And Mechanical Properties Of Sn-Ag-Cu Solders With Minor Additions Of Al And Zn, Yee Mei Leong

Student Works (2020-2029)

Driven by the recent trend towards miniaturization of lead free electronic products, researchers are putting immense efforts to improve the properties and reliability of Sn based solders. Recently, much interest has been shown on low silver (Ag) content solder SAC 105 (Sn-1.0Ag-0.5Cu) solder because of economic reasons and improvement of impact resistance as compared to SAC387(Sn-3.8Ag-0.7Ag). The present work investigates the effect of minor (0.1-0.5wt.%) Aluminium (Al) and Zinc (Zn) addition to SAC105 on the bulk and interfacial structure between solder and copper substrate during reflow and after thermal aging , the mechanical properties of the solder joint and the …


Engineering Properties And Microstructural Characteristics Of Cement And Geopolymer Based Mortars Using Nontraditional Supplementary Cementitious Materials, Mathialagan Sumesh Jul 2020

Engineering Properties And Microstructural Characteristics Of Cement And Geopolymer Based Mortars Using Nontraditional Supplementary Cementitious Materials, Mathialagan Sumesh

Student Works (2020-2029)

The concrete repair and rehabilitation industry grows rapidly due to deterioration, damage and defects in concrete structures. For various reasons, the concrete construction industry is not sustainable; because it consumes huge quantities of virgin materials, the usage of Portland cement as prime binder. The production of cement is a major contributor to greenhouse gas emissions. In addition, the high cost of commercial repair material. Therefore, it is necessary to develop cost-effective alternative repair materials for concrete repairs. There have been many standard repair materials available in the market, which are costly and not affordable to common people. However, research works …


Development Of Nano Carbon And Conducting Polymers Based Ternary Composites For Supercapattery, Iqbal Javed Jul 2020

Development Of Nano Carbon And Conducting Polymers Based Ternary Composites For Supercapattery, Iqbal Javed

Student Works (2020-2029)

Although significant efforts have been devoted on the development of energy storage systems such as batteries and fuel cells in the past decades, the low power density, short cyclic life and high maintenance cost have kept them away from many applications. Alternatively, supercapattery which has the characteristic features of batteries as well as supercapacitors has gained much attention because of its rapid charge/discharge mechanism, long life cycle, and high power density. However, supercapattery generally suffers from poor energy density. This research aims to develop carbon and conducting polymers based ternary nanocomposites for high performance supercapattery. Pristine metal oxide nanostructures suffer …


Synthesis And Application Of Ceramic Paste For High-Temperature Electronic Packaging, Ardalan Nasiri Jul 2020

Synthesis And Application Of Ceramic Paste For High-Temperature Electronic Packaging, Ardalan Nasiri

Graduate Theses and Dissertations

This dissertation research focused on the synthesis and application of ceramic paste for high-temperature applications. An alumina paste material comprising aluminum dihydric phosphate and alumina powder was developed for high-temperature electronic packaging. Nano aluminum nitride and nano-silica powders were embedded to promote the paste curing process, limit the grain growth, and increase its bond shear strength. The chip-to-substrate bond strength was enhanced and met the MIL-STD requirements for die-attach assembly. Its encapsulation property was improved with fewer cracks compared to similar commercial ceramic encapsulants. The die-attach material and encapsulation properties tested at 500°C showed no defect or additional cracks. Thermal …