December 2021 - Msepostdoc-list

REMINDER: Preliminary Exam Seminar Anna Murray, Thursday, December 9, 2021 at 12:30pm
by Contreras, Joshua Andres 08 Dec '21

08 Dec '21

Reminder: MATERIALS ENGINEERING SEMINAR "Alkali Treatments for Solution Processed Cu(In, Ga)(S, Se)2 Films and Photovoltaic Devices" By Anna Murray Purdue MSE Preliminary Exam Advisor: Professor Carol Handwerker and Professor Rakesh Agrawal ABSTRACT The world is increasingly in need of renewable energy sources that can be deployed on a large scale. Cu(In, Ga)(S, Se)2 (CIGSe) solar photovoltaic devices are highly efficient when fabricated through vacuum processes, especially with recent developments in heavy alkali (K, Rb, Cs) post-deposition treatments pushing record efficiency up to 23.35%. Solution processes such as nanoparticles and molecular precursors have the potential to produce the same material through more scalable and less costly methods, but record efficiency for these devices lags behind at 18.3%. Heavy alkali post deposition treatments increase band gap and copper depletion at the surface of p-type CIGSe, allowing for a better interface with the n-type CdS buffer layer. This study aims to understand the mechanisms by which heavy alkalis improve vacuum processed CIGSe device efficiency in order to use heavy alkali treatments on solution processed CIGSe films. This involves studying proposed theoretical reasons for experimentally measured optoelectronic property improvement in order to predict which changes will also occur in solution processed CIGSe, and utilize these treatments for higher efficiency devices. This also requires understanding the differences in phase transformations and grain sintering behavior between the same material when it is made through vacuum and solution processes. Heavy alkali post deposition treatments for solution processed CIGS are of particular interest, as this may positively affect the electrical properties with fewer changes in the film microstructure. This study aims to predict how to best design these treatments, then identify changes in material properties that will lead to high efficiency devices. Careful examination of nano/microscale material properties is necessary in order to holistically understand changes in device efficiency as well as the mechanisms that lead to these changes. Date: Thursday, December 9, 2021 Time: 12:30pm Place: HAMP 2021 or https://purdue.webex.com/join/carolh [cid:image004.jpg@01D7EC36.CC528C30] Josh Contreras Administrative Assistant School of Materials Engineering Neil Armstrong Hall of Engineering Office: 765-494-4100 [3749DD84]<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.purdue.edu_-3Futm-…>

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REMINDER: Preliminary Exam Seminar, Tomorrow, Thursday, December 9, 9 AM
by Morgan, Yuan-Yu Karen 08 Dec '21

08 Dec '21

From: Msegradstudent-list <msegradstudent-list-bounces(a)ecn.purdue.edu> On Behalf Of Morgan, Yuan-Yu Karen Sent: Tuesday, November 23, 2021 10:14 AM To: msegradstudent-list(a)ecn.purdue.edu; msefaculty-list(a)ecn.purdue.edu; msepostdoc-list(a)ecn.purdue.edu Cc: Ku Blanco, Aury Y <akublanc(a)purdue.edu> Subject: [msegradstudent-list] Preliminary Exam Seminar, Thursday, December 9, 9 AM Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Reliability of Recycled Carbon Fiber Reinforced Polymers (rCFRPs) for Sustainable High-Volume Composites" By Morgan Chamberlain Purdue MSE Preliminary Exam Advisor: Professor Jan-Anders Mansson ABSTRACT The high performance and lightweighting advantages of carbon fiber reinforced polymer composites (CFRPs) have become integral within industries such as aerospace, automotive, and sporting goods. However, the growing demand for CFRPs is met with an equally pressing need for sustainable alternatives to the harsh environmental impact that virgin carbon fiber (vCF) manufacturing entails. Additionally, the upcoming end of service life for thousands of aircraft that were manufactured at the forefront of CFRP technology will provide an additional 196,000 tons of carbon fiber waste by 2025, compared to the average 94,000 tons that is already landfilled annually. Hence there is a considerable need to bring recycled carbon fiber reinforced polymers (rCFRPs) into high-volume composites manufacturing as a sustainable alternative to landfill disposal of CFRP waste. This review analyzes the development of carbon fiber recycling technologies, as well as the more recent progress in manufacturing with the recycled material. Challenges are presented that currently hinder the scalability of rCFRPs at high volumes, including fiber surface defects and variability in length retention. Despite the difficulties that these complexities introduce, recycled carbon fiber (rCF) has shown to have excellent retention of mechanical properties, conditional on the optimization of the recycling process. Hence additional research is needed to improve rCFRP processing and assess the reliability of rCFRP structures. The final portion of this work analyzes how the Weibull distribution function can address these gaps by providing a statistical analysis of the mechanical reliability of recycled materials. In this context, understanding the complexity of the current state of recycled carbon fiber, and the difficulties in manufacturability that come with its many forms, is paramount in advancing processing technologies and broadening applications of rCFRPs. Date: Thursday, December 9, 2021 Time: 9:00 AM Place: Webex--https://purdue.webex.com/meet/jmansson Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Polishing Lab Chemical Update
by Jennifer Louise Fifer 07 Dec '21

07 Dec '21

Hi ARMS 2132 Researchers, Good news! REM has approved us to use the following chemicals again: * Nitric Acid (You are still prohibited from making Nital. All Nital use must be from a commercially made solution.) * Hydrofluoric Acid (Note: You will not be given the key to the HF cabinet without your HF buddy and proper training.) * Perchloric Acid * Base Piranha Solution At this time, the MSE Safety Committee plans to continue to keep all acids, oxidizers, and nital in the locked cabinets. You are still required to submit a hazard assessment (HA) and SDS/SOP in order access chemicals in these groups. Stay Safe, Jenni Fifer Safety & Mechanical Testing Lab Technician Materials Science & Engineering Purdue University Phone: 765-494-9718 Email: fiferj(a)purdue.edu

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REMINDER: Preliminary Exam Seminar, tomorrow, Wednesday, December 8, 11 AM
by Morgan, Yuan-Yu Karen 07 Dec '21

07 Dec '21

From: Msegradstudent-list <msegradstudent-list-bounces(a)ecn.purdue.edu> On Behalf Of Morgan, Yuan-Yu Karen Sent: Tuesday, November 23, 2021 10:43 AM To: msegradstudent-list(a)ecn.purdue.edu; msefaculty-list(a)ecn.purdue.edu; msepostdoc-list(a)ecn.purdue.edu Cc: Ku Blanco, Aury Y <akublanc(a)purdue.edu> Subject: [msegradstudent-list] Preliminary Exam Seminar, Wednesday, December 8, 11 AM Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Surface Precipitation and Growth of Bismuth Particles in Sn-Ag-Cu Solder Joints" By John Wu Purdue MSE Preliminary Exam Advisor: Professor Nikhilesh Chawla ABSTRACT Since the widespread use of Pb-free solders, many different types of elements have been added into solders to form alloys of ideal mechanical behavior. Alloying Bismuth (Bi) to the commonly seen Tin-Silver-Copper (SAC) solder systems have been especially of interest, as the addition of Bi is able to improve the overall mechanical properties and lower the melting point for more flexible assembly processes. It has been previously reported that low amounts of bismuth added to SAC305 solders would result in a precipitation effect on the polished surface. However, the growth rate and mechanisms of these precipitates at the early stages of surface exposure have not been carefully observed. The approach in attempt to explain early stage bismuth precipitation was achieved by re-polishing already precipitated surfaces. The act of re-exposure and resetting the precipitation cycle allowed calculation of precipitate growth. The results of precipitate size relation to time indicated that precipitation was strongly driven by surface diffusion. A parametric correlation between growth rate and growth mechanism is presented. Date: Wednesday, December 8, 2021 Time: 11:00 AM Place: https://purdue.webex.com/meet/nikc Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Preliminary Exam Seminar Friday, December 17, 2021 at 1pm; ARMS 2119 or WebEx
by Contreras, Joshua Andres 07 Dec '21

07 Dec '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Cellulose Nanomaterials and Their Composites in the Field of Food Packaging" By Jingxuan Zhang Purdue MSE Preliminary Exam Advisor: Professor Jeffrey Youngblood ABSTRACT Currently used materials for food packaging are mostly oil-based polymers, and environmental pollution due to those materials represents one of the biggest concerns. The research in eco-friendly and sustainable materials for food packaging applications has accelerated for past years. Plant-based cellulose nanomaterials/nanocelluloses are biodegradable and non-toxic and have relatively high mechanical properties. However, the compatibility issue between the hydrophobic polymer matrix and the hydrophilic nanocellulose is one of the main obstacles that hinder applications within food packaging industry. In this study, we will compare cellulose nanomaterials and tradition al oil-base polymers, review the major ways of chemical modifications on cellulose nanomaterials and how they tune the mechanical and barrier property of the composite. Also, both traditional and modern ways of material processing is reviewed in this study. Finally, instead of the conventional NC/polymer composites that use nanocellulose as the filler, a novel way that use cellulose nanomaterials as the major component for packaging will be reported. Date: Friday, December 17, 2021 Time: 1:00pm Place: ARMS 2119 or https://purdue.webex.com/webappng/sites/purdue/dashboard/pmr/jpyoungb [cid:image004.jpg@01D7EB4A.1701F330] Josh Contreras Administrative Assistant School of Materials Engineering Neil Armstrong Hall of Engineering Office: 765-494-4100 [3749DD84]<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.purdue.edu_-3Futm-…>

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Preliminary Exam Seminar for Venkat Kasi on Friday, January 7, 2022
by Contreras, Joshua Andres 03 Dec '21

03 Dec '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Cold Atmospheric Plasma (CAP)-Assisted Surface Modification and Functional Materials Deposition for Flexible Electronic Devices" By Venkat Kasi Purdue MSE Preliminary Exam Advisor: Professor Rahim Rahimi ABSTRACT Functional thin films consisting of inorganic, organic, or hybrid materials are considered the backbone of electronic devices for many different applications ranging from flexible displays to sensors. The use of additive manufacturing for the fabrication of flexible electronics has significantly increased over the last few decades. Compared to the traditional subtractive etching and photolithography processes, the manufacturing process of flexible electronics through additive manufacturing offers many benefits including faster time to market through rapid prototyping, aptness to on-demand and small batch fabrication, roll-to-roll manufacturing, significant reduction in waste generation, and elimination of complex vacuum systems. However, the use of traditional additive manufacturing techniques such as screen printing, inkjet printing, and gravure printing is also limited by the requirement of solvent processable inks for the deposition of functional coatings. Cold atmospheric plasma chemical vapor deposition (CAP-CVD) has become an attractive additive manufacturing technology to synthesize and deposit different organic and inorganic materials directly onto the desired substrate under atmospheric conditions. In this work, we investigate for the first time the possibility of using CAP-CVD as an alternative approach to deposit functional materials for flexible electronic applications under atmospheric conditions. Also, as part of this investigation, we have addressed one of the key challenges in the field of electrochemical sensors, which is the water layer formation at the interface due to weak bonding between ion-selective membrane and the electrode causing potential drift and inconsistency in potential responses. Date: Friday, January 7, 2022 Time: 12:00pm(noon) - 4:00pm Place: https://purdue.webex.com/meet/rrahimi [cid:image004.jpg@01D7E82F.3E3A8B10] Josh Contreras Administrative Assistant School of Materials Engineering Neil Armstrong Hall of Engineering Office: 765-494-4100 [3749DD84]<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.purdue.edu_-3Futm-…>

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REMINDER: Preliminary Exam Seminar for Chengyang Zhang on Monday, December 13, 2021
by Contreras, Joshua Andres 03 Dec '21

03 Dec '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "VO2: Metal-insulator Transition and Ferroelectric Heterostructures" By Chengyang Zhang Purdue MSE Preliminary Exam Advisor: Professor Shriram Ramanathan ABSTRACT Owing to the fascinating metal-insulator transition (MIT), vanadium dioxide (VO2) has attracted much attention in terms of material physics, synthesis, and device applications. VO2 undergoes an MIT showing several orders of resistivity change near room temperature at ~68°C. The phase transition that can be triggered both thermally and electrically renders VO2 thin films a promising candidate for sensors, smart windows, MEMS actuators, and computing applications, etc. However, the synthesis of high quality, phase pure VO2 thin films is extremely challenging due to the abundant stable phases vanadium and oxygen could form. This document summarizes the physical properties of VO2 and the underlying mechanisms of the MIT. Subsequently, synthesis, structural, and electrical characterizations of epitaxial and polycrystalline VO2 thin films were explored, and the influence of stoichiometry and lattice strain on the MIT properties were examined. Finally, novel VO2/ferroelectric heterostructure device concepts with intriguing performance were introduced. Date: Monday, December 13, 2021 Time: 1:00pm - 4:30pm Place: Virtual-https://purdue.webex.com/meet/shriram [cid:image004.jpg@01D7E82B.F88013E0] Thank you Josh Contreras Administrative Assistant School of Materials Engineering Neil Armstrong Hall of Engineering Office: 765-494-4100 [3749DD84]<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.purdue.edu_-3Futm-…>

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REMINDER: Preliminary Exam Seminar
by Contreras, Joshua Andres 03 Dec '21

03 Dec '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Microstructure and Defects in High-Strength Aluminum Alloys Produced by Selective Laser Melting" By Daniel Sinclair Purdue MSE Preliminary Exam Advisor: Professor Nikhilesh Chawla ABSTRACT Since the emergence of additive manufacturing (AM) techniques in the 1980's, the application of selective laser melting (SLM) has grown a niche method of prototyping to an enabling technology for the production of high-performance structural alloys. The paradigm shift associated with additive design is of particular interest to engineering fields like aerospace and automotive engineering, where improved efficiency of design has the potential to reduce weights and improve performance. Aluminum alloys, which constitute the most used light alloy family in aerospace, are of particular interest due to their natural synergy with the goal of weight reduction. However, issues with processability have so far limited the use of precipitation-strengthened alloy compositions. Porosity and hot cracking caused by SLM lead to insufficient mechanical performance, requiring processing controls and alloying additions which minimize the cracking susceptibility of age-hardening alloys. Recent research into these methods has shown competitive mechanical properties in SLM aluminum alloys relative to their wrought counterparts. The addition of ceramic or metallic particles during SLM serves to refine and mechanically reinforce the manufactured matrix. To explore the potential and shortcomings of SLM of high-strength aluminum, characterization of microstructure, defects, and mechanical properties is discussed. Additionally, initial results from the characterization of an SLM alloys produced by reactive additive manufacturing (RAM) are presented to address routes for the improvement of high-strength alloys. Preliminary work in this area has examined AA7050-RAM2, produced by Elementum 3D, through quantitative stereography, micro- and nano-hardness testing, and correlative tomography to understand the reaction of metallic particles with the 7050 aluminum alloy in situ as a method of grain refinement. Date: Wednesday, December 17, 2021 Time: 9:00 AM Place: https://purdue.webex.com/meet/nikc [cid:image004.jpg@01D7E82B.42AC8800] Josh Contreras Administrative Assistant School of Materials Engineering Neil Armstrong Hall of Engineering Office: 765-494-4100 [3749DD84]<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.purdue.edu_-3Futm-…>

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REMINDER: Preliminary Exam Seminar, December 6, Monday, 9:30 AM by Webex
by Morgan, Yuan-Yu Karen 03 Dec '21

03 Dec '21

From: Msegradstudent-list <msegradstudent-list-bounces(a)ecn.purdue.edu> On Behalf Of Morgan, Yuan-Yu Karen Sent: Monday, November 22, 2021 4:51 PM To: msegradstudent-list(a)ecn.purdue.edu; msefaculty-list(a)ecn.purdue.edu; msepostdoc-list(a)ecn.purdue.edu Cc: Ku Blanco, Aury Y <akublanc(a)purdue.edu> Subject: [msegradstudent-list] Preliminary Exam Seminar, December 6, Monday, 9:30 AM Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Polymer Infiltration and Pyrolysis Processing of Carbon/Carbon Composites" By Edwin Romero Purdue MSE Preliminary Exam Advisor: Professor Rodney Trice ABSTRACT The low density and high thermostability of bulk carbon make carbon fiber-reinforced carbon matrix composites a good candidate for hypersonic applications. To obtain a pure carbon matrix, a polymer matrix composite is thermally decomposed in an oxygen-free atmosphere, resulting in weight loss and a porous matrix structure. The thermomechanical properties of the porous composite can be improved using polymer infiltration and pyrolysis (PIP) processing, where infiltration and conversion of a secondary polymer causes a carbon build-up on pore walls. This simultaneously decreases the total pore volume and increases the carbon matrix density, but since a portion of the secondary polymer is gasified, some residual porosity is left behind. As a result, several cycles of PIP are needed to obtain bulk densities >90%. This review focuses on some aspects of infiltration for carbon/carbon composites that have been used to reduce densification cycles. Date: December 6, 2021 Time: 9:30 AM Place: https://purdue.webex.com/meet/rtrice Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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(Corrected) Preliminary Exam Seminar, Dec 16, Thursday, 10 AM by Webex
by Morgan, Yuan-Yu Karen 02 Dec '21

02 Dec '21

Please consider attending this seminar: "Time-Resolved Microstructural Characterization and Properties of the Apis Mellifera Honeycomb" By Rahul Franklin Purdue MSE Preliminary Exam Advisor: Professor Nikhilesh Chawla ABSTRACT The natural honeycomb, with its repeating hexagonal lattice cells made out of wax, is one of nature's best engineered structures. Even though the honeycomb has inspired several modern engineering structures, an understanding of how the bees build them is lacking. Further, all previous works on studying the structure of the honeycomb have been based on 2D microscopy techniques or by direct visual observations. As a result, several seminal features of the comb microstructure, and how it is built have been overlooked and ignored. In this talk, I will describe a series of experiments based on interrupted, time-resolved x-ray microscopy to study the mechanisms for building the comb as a function of time. For the first time, the precise mechanisms by which the bees build the combs, as well as the heterogeneous microstructure of the combs will be discussed. The findings of this work will help us in elucidating this problem and could have several widespread implications in fields such as additive manufacturing, composite materials, synthetic materials, and entomology. Date: December 16, Thursday, 2021 Time: 10:00 AM Place: Webex- https://purdue.webex.com/meet/nikc Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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