Materials Science and Engineering Commons^™

Design Of Natural Rubber Extraction From Tks Dandelion, Jehad S. Alrawajfeh, Trevor Cody, Jason Pogozelski

Williams Honors College, Honors Research Projects

A design was developed for a controlled environment agriculture 3D greenhouse to grow and harvest TKS dandelions, as well as a processing plant to extract natural rubber and inulin from the roots. The design capacity was scaled for both pilot- and full-scale production: 100 and 100,000 tonnes of natural rubber per year, respectively. The byproducts of the process were dandelion greens, inulin, cellulose, and glucose; all of these except for cellulose were able to be valorized. The greenhouse was designed based on existing 3D hydroponic growing environments, and the extraction process was designed based on the original TKS dandelion extraction …

Pitting Corrosion Of 410 Stainless Steel In Hcl Solutions, Paul D. Krell

Williams Honors College, Honors Research Projects

410 stainless steel (SS) is a material used in HCl services, such as distillation column trays in oil refineries. Unlike other alloys, however, the oil refining industry lacks a good reference for the corrosion rate of 410 SS at the varying HCl concentrations and temperatures the material might experience as trays in crude unit distillation columns. The goal of this project is to fill that knowledge gap. The corrosion behavior of 410 SS in HCl environments of pH 0.50, 1.25, 2.25, 3.25, and 4.25 at temperatures of 38, 52, 79, and 93°C was investigated using several methods. Cyclic potentiodynamic polarization …

Design And Testing Of Flexible Lithium-Ion Batteries, Ryan C. Kramanak, Matt A. Murrow, Matt Stolfer, Jered Tyler, Aaron Moser

Williams Honors College, Honors Research Projects

The goal of this disquisition is to delineate the development of a material and casing suitable for flexible lithium-ion rechargeable batteries. Development of these cells is driven by increasing interest in portable and flexible electronics. The goal is to implement them into items such as smart cards, wearable electronics, novelty packages, flexible displays, and transdermal drug delivery patches. To accomplish this task, a number of individual cathode compounds were explored that used different compositions of lithium cobalt oxide and other compounds. These cells were tested in a generic and easily manufacturable cell casing. After the catholyte compound testing was completed …

Characterization & Extraction Of Extracellular Matrix From Porcine Adipose Tissue, Rahulkumar Kantibhia Bhoi

Open Access Theses & Dissertations

Tissue in particular extracellular matrix(ECM) plays a vital role in the growth and the function of each cell types and promote tissue regeneration and repair an impair organs. Many techniques have been developed so far to decellularized porcine tissue for the purpose to use as regenerative medicine and in tissue engineering. We aimed to optimized a method to decellularized porcine tissue while effectively eliminating xenogeneic epitopes, lipids and to retain necessary component of it intact without disrupting ECM. We have developed 2-week protocol to optimize well preserved ECM component that may keep xenogeneic biomaterial for tissue engineering and regenerative medicine. …

Signal-To-Noise Ratio Enhancement Using Graphene-Based Passive Microelectrode Arrays, Sepideh Rastegar, Justin Stadlbauer, Kiyo Fujimoto, Kari Mclaughlin, David Estrada, Kurtis D. Cantley

Materials Science and Engineering Faculty Publications and Presentations

This work is aimed toward the goal of investigating the influence of different materials on the signal-to-noise ratio (SNR) of passive neural microelectrode arrays (MEAs). Noise reduction is one factor that can substantially improve neural interface performance. The MEAs are fabricated using gold, indium tin oxide (ITO), and chemical vapor deposited (CVD) graphene. 3D-printed Nylon reservoirs are then adhered to the glass substrates with identical MEA patterns. Reservoirs are filled equally with a fluid that is commonly used for neuronal cell culture. Signal is applied to glass micropipettes immersed in the solution, and response is measured on an oscilloscope from …

Application Of Artificial Neural Networks To Identify Equilibration In Computer Simulations, Michael H. Leibowitz, Evan D. Miller, Michael M. Henry, Eric Jankowski

Materials Science and Engineering Faculty Publications and Presentations

Determining which microstates generated by a thermodynamic simulation are representative of the ensemble for which sampling is desired is a ubiquitous, underspecified problem. Artificial neural networks are one type of machine learning algorithm that can provide a reproducible way to apply pattern recognition heuristics to underspecified problems. Here we use the open-source TensorFlow machine learning library and apply it to the problem of identifying which hypothetical observation sequences from a computer simulation are "equilibrated" and which are not. We generate training populations and test populations of observation sequences with embedded linear and exponential correlations. We train a two-neuron artificial network …

การเพิ่มการกักเก็บของแคลเซียมคาร์บอเนตชนิดตกตะกอนและนาโนแคลเซียมคาร์บอเนตในกระดาษโดยใช้พอลิอะคริเลตและพอลิอะคริลาไมด์, มนต์นภา ลัภนพรวงศ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มุ่งศึกษาถึงผลจากการเติมแคตไอออนิกพอลิอะคริลาไมด์เป็นสารเพิ่มการตกค้างและโซเดียมพอลิอะคริเลตเป็นสารช่วยกระจายตัว เพื่อเพิ่มปริมาณการกักเก็บตัวเติม 2 ชนิด ได้แก่ แคลเซียมคาร์บอเนตชนิดตกตะกอนและนาโนแคลเซียมคาร์บอเนตภายในเนื้อกระดาษ โดยใช้เยื่อเคมีฟอกทางการค้าในอัตราส่วนเยื่อใยสั้นและเยื่อใยยาวเท่ากับ 70:30 ของน้ำหนักแผ่นทดสอบ นำไปบดเยื่อเพื่อให้มีค่าสภาพการระบายน้ำ 325 ± 25 mL CSF จากนั้นศึกษาถึงปริมาณการเติมแคตไอออนิกพอลิอะคริลาไมด์และโซเดียมพอลิอะคริเลตที่เหมาะสมสำหรับตัวเติมแคลเซียมคาร์บอเนตทั้งสองชนิด เพื่อให้มีปริมาณการกักเก็บภายในเนื้อกระดาษที่ร้อยละ 30 ของน้ำหนักแผ่นทดสอบ โดยพบว่าเมื่อเติมแคตไอออนิกพอลิอะคริลาไมด์ที่ร้อยละ 1.1 ของน้ำหนักเยื่อแห้งส่งผลให้มีปริมาณการกักเก็บสูงสุด แต่อย่างไรก็ตามพบว่าการเติมโซเดียมพอลิอะคริเลตในสารแขวนลอยแคลเซียมคาร์บอเนต ทำให้ปริมาณการกักเก็บตัวเติมภายในกระดาษลดลง โดยเฉพาะในภาวะที่เติมนาโนแคลเซียมคาร์บอเนตเนื่องจากมีการกระจายตัวของอนุภาคที่มากเกินไป ส่งผลให้อนุภาคเล็ก ๆ ลอดไปกับน้ำผ่านรูตะแกรงระหว่างทำการขึ้นแผ่น เมื่อได้ปริมาณที่เหมาะสมในการเติมสารเติมแต่งแล้วนั้นจึงได้ศึกษาถึงการใช้ร่วมกันระหว่างแคลเซียมคาร์บอเนตชนิดตกตะกอนและนาโนแคลเซียมคาร์บอเนตในสัดส่วนที่ต่างกัน ตั้งแต่ 100: 0 75:25 50:50 25:75 ถึง 0:100 ในการปรับปรุงสมบัติกระดาษโดยเทียบกับภาวะที่ไม่เติมสารเติมแต่งใด ๆ พบว่าแม้ว่าแคลเซียมคาร์บอเนตชนิดตกตะกอนและนาโนแคลเซียมคาร์บอเนตจะให้สภาพพิมพ์ได้และสมบัติทางทัศนศาสตร์ใกล้เคียงกัน แต่เมื่อสัดส่วนของนาโนแคลเซียมคาร์บอเนตเพิ่มขึ้นกลับทำให้ความเรียบของผิวกระดาษและความหนาแน่นของแผ่นทดสอบลดลง นอกจากนี้เมื่อนำไปทดสอบความแข็งแรงต่อแรงดึงและแรงฉีกพบว่าเกิดการฟุ้งกระจายของอนุภาคแคลเซียมคาร์บอเนตมากขึ้นเมื่อแผ่นทดสอบฉีกขาด

A Study Of Copper And Aluminum Incorporated Chromium Oxide Core-Shell Magnetic Nanoparticles, Tamzid Ibn Minhaj

Graduate Theses/Dissertations

The structural and magnetic properties of copper (Cu) and aluminum (Al) -incorporated chromium oxide (α-Cr₂O₃, i.e., chromia) inverted core-shell nanoparticles (CSNs) were investigated. The objectives of this study were to determine the role of the substituting (for chromium, Cr) element and of Cu concentration on governing the magnetic properties of the CSNs. For synthesis of the CSNs, α-Cr₂O₃ nanoparticles were first grown using microwave assisted synthesis whereupon a hydrothermal nanophase epitaxy (HNE) method was used to incorporate Cu or Al in the chromia-based shell of the nanoparticles. The morphology, structure and size characteristics …

Dft Study On The Li Mobility In Li-Ion-Based Solid-State Electrolytes, Shafiqul Islam

Graduate Theses/Dissertations

I have investigated the diffusion mechanisms of Li-ion in amorphous lithium phosphite (LiPO₃) with addition of sulphur. By applying the nudge elastic band (NEB) method in crystal LiPO₃ and Li₃PO₄, I confirmed the easing of diffusion pathways for Li ion in LiPO₃ which is consistent with the previous theoretical finding[1]. From the diffusion study in 0.5 Li₂O- 0.5 P₂O₅ and 0.4 Li₂SO₄ – 0.6 (Li₂O-P₂O₅) melts above 3000K performed with ab-initio molecular dynamics (AIMD), produces identical outcome as …

Study Of Nano-Bio Interfaces In Nano-Bio Conjugates: Nanoparticles Of Zinc Oxide (Zno) And Biomolecules Of Glucose, Cytosine, And Thymine, Bithi Paul

Graduate Theses/Dissertations

Nano conjugates, composites of inorganic nanomaterials and bio molecules such as DNA, RNA and proteins, establish a sequence of wide varieties of nano-bio boundaries. The formation of these boundaries strongly depends on bio physicochemical reaction of biomolecules coated on the surface of nanomaterials. I am investigating various nano-bio conjugates consisting of zinc oxide (ZnO) nanoparticles with simple biomolecules including glucose and the nitrogenous bases of DNA such as cytosine and thymine. All nano-bio conjugates were fabricated using a standard bio-chemical synthesis process. Structural, physical, bio-chemical interface properties of nano-bio composites were probed using X-ray diffraction (XRD), Raman spectroscopy, and photoluminescence …

Study Of Multiferroic Properties Of Ferroelectric- Ferromagnetic Heterostructures Bzt-Bct/Lsmo, Md Abdullah-Al Mamun

Graduate Theses/Dissertations

Currently, there has been a flurry of research focused on multiferroic materials due to their potential applications. Lead (Pb)-based ferroelectric and multiferroic materials (PZT, PMN-PT, PZN-PT etc.) have been widely used for sensors, actuators, and electro-mechanical applications due to their excellent dielectric and piezoelectric properties. However, these materials are facing global restriction due to the toxicity of Pb. In this thesis, multiferroic properties of ferroelectric-ferromagnetic heterostructures consist of Pb-free perovskite oxides 0.5Ba(Zr_0.2Ti_0.8)O₃-0.5 (Ba_0.7 Ca_0.3)TiO₃ (BZT-BCT) and La_0.7Sr_0.3MnO₃ (LSMO) have been studied. The heterostructures BZT-BCT/LSMO were …

Development Of Highly Sensitive And Selective Breathing Sensors Using Molecular Imprinted Filtering For Diabetic And Alcoholic Patients, Md. Saleh Akram Bhuiyan

Electronic Theses and Dissertations

Wellness sensor technology is an emerging diagnostic test research field, which mostly deal with the point of care of the patients in the recent days. Due to the lack of awareness from the patients, most diseases cannot be detected in due time. This led to worse conditions, such as diabetic and alcoholic syndrome. Therefore, many research groups have been working to develop portable sensor devices that can track serious diseases. These include diabetic and alcoholic biomarkers in breathing. These devices have very high selectivity and reliability. However, the major limitation of biomarkers is that it deals with the bio-molecular based …

Tightening The Loop On The Circular Economy: Distributed Plastic Recycling With An Open Source Recyclebot, Shan Zhong

Dissertations, Master's Theses and Master's Reports

Following the goals of a circular economy, the growth of both plastic consumption and prosumer 3-D printing are driving an interest in producing 3-D printer filament from waste plastic. However, traditional recycling can have a significant environmental impact as it demands the collection and transportation of relatively low-density waste plastics to collection centers and reclamation facilities for separation and reconstruction. Compared to the traditional recycling, distributed recycling (where consumers directly recycle their own waste) has the potential to reduce energy consumption because it can save the energy for transportation needed in conventional recycling. A promising method of such distributed plastic …

Electro-Optic Contact Poling Of Polymer Waveguide Devices And Thin Films, Michael Briseno

Dissertations, Master's Theses and Master's Reports

Optical communication is a high speed, large bandwidth, low cost, and power efficient method of transferring data over short-haul and long-haul channels. Optical communication requires devices (optical modulators) that utilize the originating electrical signal information to modulate a corresponding optical signal. State of the art optical modulators can be used for communicating signals at modulation frequencies up to 100 GHz and faster. Polymer modulators are used over lithium niobate due to the large potential electro-optic coefficient, which has been shown to be as high as 226 pm/V in thin films.

Organic electro-optic polymers used in thin film modulators contain nonlinear …

Controlling Properties Of Agglomerates For Chemical Processes, Joseph A. Halt

Dissertations, Master's Theses and Master's Reports

Iron ore pellets are hard spheres made from powdered ore and binders. Pellets are used to make iron, mainly in blast furnaces. Around the time that the pelletizing process was developed, starch was proposed as a binder because it’s viscous, adheres well to iron oxides, does not contaminate pellets and is relatively cheap. In practice, however, starch leads to weak pellets with rough surfaces – these increase the amount of dust generated within process equipment and during pellet shipping and handling. Thus, even though the usual binder (bentonite clay) contaminates pellets, pelletizers prefer it to starch or other organics.

This …

Mse Annual Report 2017, Department Of Materials Science And Engineering, Michigan Technological University

Department of Materials Science and Engineering Annual Reports

Table of Contents

• Faculty and Staff News
• Faculty Research
• Student News
• Senior Design Teams
• Graduate Student News
• Outreach
• Alumni News
• By the Numbers
• Scholarships

The Effect Of Pore Density And Distribution On Fatigue Weak Links In An A713 Cast Aluminum Alloy, Rami A. Almatani

Theses and Dissertations--Chemical and Materials Engineering

The effects of pore density and distribution were investigated on the fatigue crack initiation behavior in an A713 sand cast aluminum alloy plate of 12 mm thickness. The applied stress- the number of cycles to failure (S-N) curves of the samples taken from 2 mm and 5 mm from the free surface were obtained using four-point bend fatigue testing at room temperature, frequency of 20 Hz, stress ratio of 0.1, sinusoidal waveform, and in ambient air. The fatigue strengths of both, the 2 mm and 5 mm samples were 60% of the yield strength (σy=171.9 MPa) of the …

Utilization Of Bio-Renewable Lignin In Building High Capacity, Durable, And Low-Cost Silicon-Based Negative Electrodes For Lithium-Ion Batteries, Tao Chen

Theses and Dissertations--Chemical and Materials Engineering

Silicon-based electrodes are the most promising negative electrodes for the next generation high capacity lithium ion batteries (LIB) as silicon provides a theoretical capacity of 3579 mAh g^-1, more than 10 times higher than that of the state-of-the-art graphite negative electrodes. However, silicon-based electrodes suffer from poor cycle life due to large volume expansion and contraction during lithiation/delithiation. In order to improve the electrochemical performance a number of strategies have been employed, such as dispersion of silicon in active/inactive matrixes, devising of novel nanostructures, and various coatings for protection. Amongst these strategies, silicon-carbon coating based composites are one …

Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick

Theses and Dissertations--Chemical and Materials Engineering

Ultrafiltration (UF) processes are often used as pretreatment before more retentive/costly processes, such as nanofiltration and reverse osmosis. This study shows the results of low-biofouling nanocomposite membranes, loaded with casein-coated silver nanoparticles (casein-Ag-NPs). Membranes were cast and imbedded with Ag-NPs using two approaches, physical blending of Ag-NPs in the dope solution (^PAg-NP/CA membranes) and chemical attachment of Ag-NPs to cast membranes (^CAg-NP/CA membranes), to determine their biofouling control properties. The functionalization of Ag-NPs onto the CA membranes was achieved via attachment with functionalized thiol groups with the use of glycidyl methacrylate (GMA) and cysteamine chemistries. The …

Understanding And Improving Manufacturing Processes For Making Lithium-Ion Battery Electrodes, Mohanad N. Al-Shroofy

Theses and Dissertations--Chemical and Materials Engineering

Lithium-ion batteries (LIBs) have been widely used as the most popular rechargeable energy storage and power sources in today’s portable electronics, electric vehicles, and plug-in hybrid electric vehicles. LIBs have gained much interest worldwide in the last three decades because of their high energy density, voltage, rate of charge and discharge, reliability, and design flexibility. I am exploring the possibility of developing battery manufacturing technologies that would lower the cost, reduce the environmental impact, and increase cell performance and durability.

This dissertation is focused firstly on understanding the effect of mixing sequence (the order of introducing materials) and optimizing the …

Charge Transport In Electronic-Ionic Composites, Long Zhang

Theses and Dissertations--Chemical and Materials Engineering

The goal of this thesis is to generate fundamental understandings of charge transport behaviors of composites consisting of garnet structured Al substituted Li₇La₃Zr₂O₁₂ (LLZO) electrolyte and LiCoO₂ electrode. In order to take full advantage of all-solid-state batteries, bulk type composite electrodes should be introduced to increase energy and power density. However, the charge utilization of bulk type composite electrodes is quite low. Understanding ionic conduction behavior is, therefore, important for improving the performance of all-solid-state batteries, because ion conduction within solids depends on effective pathways. Electronic conductivity can be easily compensated by …

Acenes, Heteroacenes And Analogous Molecules For Organic Photovoltaic And Field Effect Transistor Applications, Devin B. Granger

Theses and Dissertations--Chemistry

Polycyclic aromatic hydrocarbons composed of benzenoid rings fused in a linear fashion comprise the class of compounds known as acenes. The structures containing three to six ring fusions are brightly colored and possess band gaps and charge transport efficiencies sufficient for semiconductor applications. These molecules have been investigated throughout the past several decades to assess their optoelectronic properties. The absorption, emission and charge transport properties of this series of molecules has been studied extensively to elucidate structure-property relationships. A wide variety of analogous molecules, incorporating heterocycles in place of benzenoid rings, demonstrate similar properties to the parent compounds and have …

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

All Graduate Theses, Dissertations, and Other Capstone Projects

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

Processing, Microstructure, And Mechanical Properties Of Zirconium Diboride-Molybdenum Disilicide Ceramics And Dual Composite Architectures, Ryan Joseph Grohsmeyer

Doctoral Dissertations

"This research had two objectives: characterization of processing-microstructure-mechanical property relationships of conventional ZrB₂-MoSi₂ ceramics at room temperature (RT) and 1500⁰C in air, and fabrication of ZrB₂-MoSi₂ dual composite architectures (DCAs) for use near 1500⁰C. Elastic moduli, fracture toughness, and flexure strength were measured at RT and 1500⁰C for 15 ZrB₂-MoSi₂ ceramics hot pressed using fine, medium, or coarse ZrB₂ starting powder with 5-70 vol.% MoSi₂, referred to as FX, MX, and CX respectively where X is the nominal MoSi₂ content. MoSi₂ decomposed during sintering, resulting in …

Optimal Design And Freeform Extrusion Fabrication Of Functionally Gradient Smart Parts, Amir Ghazanfari

Doctoral Dissertations

"An extrusion-based additive manufacturing process, called the Ceramic On-Demand Extrusion (CODE) process, for producing three-dimensional ceramic components with near theoretical density was developed. 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. Sample parts made of alumina and fully stabilized zirconia were produced using this process and their mechanical properties including density, strength, Young's modulus, Weibull modulus, toughness, and hardness were examined. Microstructural evaluation was also performed to measure the grain size, and critical flaw sizes were obtained. The results indicate that the proposed method enables fabrication of geometrically complex parts with superior mechanical properties. Furthermore, several methods were developed to increase the productivity of the CODE process and enable manufacturing of functionally graded materials with an optimum distribution of material composition. As an application of the CODE process, advanced ceramic components with embedded sapphire optical fiber sensors were fabricated and properties of parts and sensors were evaluated using standard test methods"--Abstract, page iv.

Dirac Surface States Of Magnetic Topological Insulators, Seng Huat Lee

Doctoral Dissertations

"Magnetic topological insulator (TI) has been theoretically proposed to be a platform for inducing magnetic monopole and exhibit fascinating quantum phenomena, whereas topological superconductor can host Majorana fermions, particles that are their own antiparticles, which can be manipulated for topological quantum computing. In this dissertation, we experimentally demonstrated that by intercalation of different transition metals in the van der Waals gaps of Bi₂Se₃ TI, magnetism and even superconductivity can be induced. In Fe_xBi₂Se₃, antiferromagnetism is induced with a transition temperature at ~ 100 K. Coexistence of the Dirac surface state with …

Imaging Of Super-Fast Dynamics And Flow Instabilities Of Superconducting Vortices, L. Embon, Y. Anahory, Ž L. Jelić, E. O. Lachman, Y. Myasoedov, M. E. Huber, G. P. Mikitik, A. V. Silhanek, M. V. Milošević, A Gurevich, E. Z. Zeldov

Physics Faculty Publications

Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong currents remains largely unexplored. Here, we use a nanoscale scanning superconducting quantum interference device to image vortices penetrating into a superconducting Pb film at rates of tens of GHz and moving with velocities of up to tens of km/s, which are not only much larger than the speed of sound but also exceed the pair-breaking speed limit of superconducting condensate. These experiments reveal formation of mesoscopic vortex channels which …

Magnetic Behavior Of Bulk And Nanostructured Mnxtas2, Lucas Paul Beving

Honors Program Theses

At its base, material science research aims to categorize specific materials by their various attributes, such as structure, integrity, electronic properties, magnetic properties, and others. By categorizing materials in this way, it becomes easier to generalize the application of a specific material to those within a broader category. The interest in materials that exhibit useful characteristics at small scales derives directly from the technology industry’s need for smaller and smaller devices. Two-dimensional materials are of great interest for this reason.

Two-dimensional materials are comprised of many single layers, or planes, stacked together to create a crystal. Each layer may be …

Mechanical Characterization Of Parts Produced By Ceramic On‐Demand Extrusion Process, Amir Ghazanfari, Wenbin Li, Ming Leu, Gregory Hilmas

Faculty Publications, Mechanical Engineering

Ceramic On‐Demand Extrusion (CODE) is an additive manufacturing process recently developed to produce dense three‐dimensional ceramic components. In this paper, the properties of parts produced using this freeform extrusion fabrication process are described. High solids loading (~60 vol%) alumina paste was prepared to fabricate parts and standard test methods were employed to examine their properties including the density, strength, Young's modulus, Weibull modulus, toughness, and hardness. Microstructural evaluation was also performed to measure the grain size and critical flaw size. The results indicate that the properties of parts surpass most other ceramic additive manufacturing processes and match conventional fabrication techniques.

ผลของการเติมเถ้าแกลบต่อการเกิดชั้นฟิล์มในกระบวนการอะลูมิไนซิงแบบผงบนนิกเกิลบริสุทธิ์, บุญฤทธิ์ เฮงประยูร

Chulalongkorn University Theses and Dissertations (Chula ETD)

การปรับปรุงกระบวนการอะลูมิไนซิงแบบผงทำได้โดยการเจือธาตุซิลิกอนเพื่อเพิ่มความเสถียรของชั้นออกไซด์ที่เกิดขึ้นในการใช้งานที่อุณหภูมิสูง ซึ่งเถ้าแกลบมีส่วนประกอบของซิลิกาอยู่มากกว่า 90 เปอร์เซ็นต์โดยน้ำหนัก ในงานวิจัยนี้จะหาความเป็นไปได้ในการใช้เถ้าแกลบแทนซิลิกาจากอุตสาหกรรม (ควอทซ์) เพื่อเจือซิลิกอนลงในกระบวนการอะลูมิไนซิงแบบผง โดยวิเคราะห์ถึงความแตกต่างของโครงสร้างผลึก สารเจือในเถ้าแกลบ ขนาดอนุภาค ลักษณะพิ้นผิวและพื้นที่ผิวจำเพาะระหว่างผงควอทซ์และผงเถ้าแกลบที่จะส่งผลต่อโครงสร้างจุลภาค โครงสร้างของสารประกอบของชั้นแพร่และปริมาณซิลิกอนที่พบในชั้นแพร่ในผิวชิ้นงานที่ใช้สารตั้งต้นเป็นควอทซ์และเถ้าแกลบ ซึ่งปริมาณสารเจือที่เติมคือ 9, 13.5, 18 เปอร์เซ็นต์โดยน้ำหนัก เผาที่อุณหภูมิ 800 และ 1000๐C เป็นเวลา 4 ชั่วโมง และทดสอบความต้านทานการเกิดออกซิเดชันที่อุณหภูมิ 1000๐C เป็นเวลา 100 ชั่วโมง ชิ้นงานที่นำมาทดสอบคือ นิกเกิลบริสุทธิ์, ชิ้นงานที่ทำอะลูมิไนซิงที่ 900๐C เป็นเวลา 4 ชั่วโมง, ชิ้นงานที่เติมควอทซ์ 13.5 เปอร์เซ็นต์โดยน้ำหนัก ทำอะลูมิไนซิงที่ 1000๐C เป็นเวลา 4 ชั่วโมงและชิ้นงานที่เติมเถ้าแกลบ 13.5 เปอร์เซ็นต์โดยน้ำหนัก ทำอะลูมิไนซิงที่ 1000๐C เป็นเวลา 4 ชั่วโมง นำชิ้นงานมาวิเคราะห์ลักษณะพื้นผิวและโครงสร้างของสารประกอบออกไซด์ที่เกิดขึ้นที่ผิว พบว่าชิ้นงานที่เติมเถ้าแกลบจะมีปริมาณซิลิกอนที่พบในชั้นแพร่มากกว่าและมีความสามารถในการต้านทานการเกิดออกซิเดชันที่อุณหภูมิสูงดีกว่าชิ้นงานที่เติมควอทซ์