November 2021 - Msepostdoc-list

Final Exam Seminar, Monday, Nov 22, 202, at 2pm in HAMP 2101
by Morgan, Yuan-Yu Karen 08 Nov '21

08 Nov '21

Please consider attending this seminar: "Compositional Effect on Low-Temperature Transient Liquid Phase Sintering of Tin Indium Solder Paste" By John Obamedo Purdue MSE M.S. Final Exam Advisors: Professor Carol Handwerker and Professor John Blendell ABSTRACT Transient liquid phase sintering (TLPS) technologies are potential low-temperature solders for sustainable replacements of lead-based solders and high-temperature lead-free solders. Compared to solid-state sintering and lead-free solders, TLPS uses lower temperatures and is, thus, suitable for assembling temperature-sensitive components. TLPS is a non-equilibrium process and determining the kinetics is critical to the estimation of processing times needed for good joining. The tin-indium (Sn-In) system with a eutectic temperature of 119°C is being considered as the basis for a TLPS system when combined with tin. Most models of TLPS include interdiffusion, dissolution, isothermal solidification, and homogenization and are based on simple binary alloys without intermediate phases. The Sn-In system has two intermediate phases and thus the reaction kinetics require additional terms in the modeling. Differential Scanning Calorimetry (DSC) has been used to measure the response of Sn-In alloys during the transient liquid phase reaction. Preparation of tin indium alloys for microstructural analysis is challenging due to their very low hardness. This study uses freeze-fracturing of the tin indium alloys to obtain sections for microstructural analysis. The combination of DSC and microstructure analysis provides information on the reaction kinetics. It was observed that the solid/liquid reaction does not proceed as quickly as desired, that is, substantial liquid remains after annealing even though the overall composition is in the single-phase region in the phase diagram. Date: Monday, Nov 22, 2021 Time: 2:00 P.M. Place: HAMP 2101

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Final Exam Seminar, Monday, November 22, 2021, 9 AM at HAMP 2118
by Morgan, Yuan-Yu Karen 08 Nov '21

08 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Phase Transformations in Multicomponent Systems for Solder Joint Reliability" By Alyssa Yaeger Purdue MSE Ph.D. Final Exam Advisors: Professor Carol Handwerker and Professor John Blendell ABSTRACT Solder joints serve as the physical and electrical connection between surface mounted components and circuit boards, and are expected to maintain that connection under stress. Shear stresses due to coefficient of thermal expansion (CTE) mismatch between component and circuit board are common during use, and can lead to fracture of the solder joint. The cracks begin near the solder-substrate interface and propagate through the joint, either through the bulk of the solder or along the interfaces of brittle phases. Therefore, the morphology of the interfacial intermetallic compounds (IMCs) can influence the crack path and whether the failure is ductile or brittle, and thus will determine the lifetime and reliability of the solder joint. Gold embrittlement has been a soldering issue for decades, although it is a broad category which indicates brittle failure due to the presence of gold, typically forming AuSn4. Mitigation of this has included the reduction of Au in the solder joint and the introduction of Cu to destabilize AuSn4-type intermetallics with the formation of (Cu,Ni,Au)6Sn5. A limit of 3wt% Au per solder joint attempted to mitigate this issue, but the methods of gold removal are not precise, and 3% is not a hard limit below which gold embrittlement does not occur. Nickel is able to substitute for Au in AuSn4, forming (Au,Ni)Sn4 in higher volumes at lower gold concentrations, making the establishment of a limit for Au in the joint more difficult. Two methods of establishing these limits are presented in this thesis: isothermal annealing, and thermal cycling. Microstructures evolve over time, even during periods of storage prior to use. Isothermal annealing above storage temperature and below the solidus promotes faster diffusion than seen in practice, due to the temperature dependence of solid state diffusion. This is also known as accelerated aging, as the time and temperature during annealing can be correlated to a different time and temperature during storage. Isothermal annealing allows potential issues, such as gold embrittlement, to be identified more quickly and prior to production, and can give an estimate of product lifetime. For Au-containing solder, Au from the bulk diffuses to the Ni interface to form (Au,Ni)Sn4 during annealing, which causes brittle failure when it forms a thick, continuous layer. Thermal cycling is another method of accelerated testing which can determine the limits of gold embrittlement. Solder joints undergo thermal cycling during product use, and this method increases the cycle frequency to induce earlier failure. This failure is determined by an increase in electrical resistance across solder joints. Failed solder joints can then be cross sectioned to examine the microstructure and crack path to determine cause of failure. Leadless ceramic chip carriers are stiff components with a low standoff height which tends to concentrate thermal expansion mismatch induced stresses in the solder and have thick Au coating, which together make them a good candidate for studies of gold embrittlement. In this thesis, it was determined that these solder joints failed in a ductile manner, determined more by the component characteristics and not as a result of gold embrittlement. A potential mitigation method for gold embrittlement in eutectic Sn-Pb solder joints is also presented in this thesis. Because one cause of gold embrittlement includes the thick, continuous layer of (Au,Ni)Sn4,it has been proposed that breakup of this layer can increase ductility and solder joint lifetime. This can be accomplished with a secondary reflow, or melting, of the solder, using the high solubility of Au in molten solder to destabilize the (Au,Ni)Sn4 and return the solder joint to a more ductile microstructure. The thermodynamics of and mechanisms leading to the destabilization of (Au,Ni)Sn4 are quantified as a function of Au concentration in the solder. The relationship between the solder compositions and microstructure, including interfacial intermetallics, and the fracture behavior of the resulting joints provides insight into the appropriate limits of Au in Sn-Pb solder joints to reduce Au embrittlement. . Date: Monday, November 22, 2021 Time: 9:00 A.M. Place: HAMP 2118

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MSE Pet Photo Contest Results
by Ku Blanco, Aury Y 08 Nov '21

08 Nov '21

Hello All!! The department has voted, and here are the top five MSE family pets you want to see on safety postings in Armstrong Hall. Make sure to stop and "Shut the Sash" on your fume hoods so you can see their adorable faces!! First Place: Tamera Fun Fact: Tamara is a cat with rich emotions even more than I have. She always gives such a contradictorily fragile, loving but a little angry meow that you know she doesn't want you to be near her but also, she doesn't want you to be near the other cat(out of obvious jealousy). We love her but also gets beaten by her a lot. She is truly an evil that steals your heart and then scratch on it because she knows you can't help loving her 🙂 [cid:image001.jpg@01D7D473.050462A0] Second Place: Chelsea Fun Fact: She doesn't watch the ball during fetch and instead just starts running, and consequently loses the ball a lot. [cid:image002.jpg@01D7D473.050462A0] Third Place: Chewy Fun Fact: He was a part of a litter of 8 other pups, which is unusually high for bulldogs. [cid:image003.png@01D7D473.050462A0] Fourth Place: Coco Fun Fact: She is so quiet (maybe related to being a rescue dog?) [cid:image004.jpg@01D7D473.050462A0] Fifth Place (Tie): Toby Fun Fact: Toby is the world's friendliest cat [cid:image005.jpg@01D7D473.050462A0] Fifth Place (Tie): Nymeria Fun Fact: Her arms and legs stick straight out when she sleeps [cid:image006.jpg@01D7D473.050462A0] Thank you for participating and sharing pictures of your pets with us! Kerry-Ann Stirrup and Caitlin Adams, MSEGSA Safety Co-Chairs and the MSE Safety Committee

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Preliminary Exam Seminar Nov 12, 1PM
by Morgan, Yuan-Yu Karen 05 Nov '21

05 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Mechanisms Behind Magnetoelectric Multiferroic Thin Films" By Jianan Shen Purdue MSE Preliminary Exam Advisor: Professor Haiyan Wang ABSTRACT The phenomenon of multiferroics with simultaneous presence of two ferroic orderings has raised great interest over the past decades owing to their scientific and technological importance. Triggered by the discovery of the first multiferroic material, Ni3B7O13I, the search for multiferroic materials has expanded significantly. Although the pioneering work has been focusing on bulk multiferroic materials, multiferroic thin films have drawn increasing attention because of their promising potentials on device applications, such as multiferroic 4-state logic memories, magnetic field sensors, multiferroic tunneling junctions, magnetoelectric memories, etc. Multiferroic properties can be established on a single-phase material, and there are assorted mechanisms for single phase multiferroics. Nevertheless, the family of single-phase materials remains small due to the fundamental contradiction between the electron configuration of d orbitals in ferroelectricity and ferromagnetism, and they are not yet usable for practical applications due to the low remnant magnetization and weak magnetoelectric coupling between two orderings. Two-phase multiferroic nanocomposite combines ferroelectricity and ferromagnetism phase into one system and exhibits stronger magnetoelectric coupling through strain mediation, which makes it a more viable and reliable material candidate for practical applications. This review first introduces the history and background of multiferroics, then discusses different mechanisms of multiferroic thin films as well as their pros and cons, finally identifies the existing critical challenges, and proposes some future perspectives. Date: November 12, 2021 Time: 1:00 PM WebEx: https://purdue.webex.com/purdue/j.php?MTID=mebb8a27f8e85d4e3183689fa0ae42932 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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REMINDER: Preliminary Exam Seminar tomorrow at 8:30 AM
by Morgan, Yuan-Yu Karen 04 Nov '21

04 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "The Impact of Strain on Bismuth-Based Oxides" By James Barnard Purdue MSE Preliminary Exam Advisor: Professor Haiyan Wang ABSTRACT The field of thin film materials with multiferroic properties (simultaneous ferromagnetism and ferroelectricity) has drawn much attention toward nanoelectronic device applications. An appealing new Bismuth oxide system has been discovered in thin film form. This BiFeMnO system, discovered by the study of a nanocomposite of BiFeO3 and BiMnO3, is strongly multiferroic. However, there are multiple phases that grow preferentially under various conditions, including a pseudocubic structure and a layered supercell structure. The growth of the desirable multiferroic layered supercell phase is contingent on a large film strain. The impact of strain on the film has been examined through lattice misfit by substrate and buffer layer selection. Film thickness has also played a role in the film characteristics. In this review, the history of the system and its recent development and tuning will be discussed, as well as the promising future work towards device applications. Date: Nov 5, Friday, 2021 Time: 8:30 AM Room: ARMS 1103 Or WebEx: https://purdue.webex.com/purdue/j.php?MTID=mab828a9cc840b6da6ef72a7363b1ca36

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REMINDER: Preliminary Exam Seminar TOMORROW, Nov. 5, Friday at 11:00 am
by Morgan, Yuan-Yu Karen 04 Nov '21

04 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Kinetics of Liquid-Solid Displacement Reactions" By Glenn Peterson Purdue MSE Preliminary Exam Advisors: Professor Michael Sangid and Professor Kenneth Sandhage ABSTRACT Defense, aerospace, and nuclear applications rely heavily on materials able to withstand extreme environments. Of potential solutions, ceramic-metal (cermet) composites can address several fundamental concerns such as temperature, mechanical behavior, and oxidation/corrosion resistance. Forming refractory metal/ultra-high temperature ceramic composites is not intuitive. A novel method of processing these materials is through reactive melt infiltration. In general terms, this is a process where a liquid fills a porous perform, and a displacement reaction occurs. A thermodynamic analysis is presented, and several models for reaction rate are developed for evaluating various controls of solid-liquid displacement reactions. Two common rate limiting steps are chemical reaction or diffusion controlled. Knowledge of reaction constants-necessary data points-must be experimentally determined and can be subsequently used to derive activation energies. These activation energies are one of the tools used to identify the rate limiting step for a given reaction. Fundamentally, determining the reaction rate for a system enables the capability to scale up a process and make usable engineering components. Date: Friday, November 5, 2021 Time: 11:00 AM Join from the meeting link https://purdue.webex.com/meet/sandhage?_ga=2.42913062.268434666.1632831811-…

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FW: 2 weeks left to make our goal!!
by Jennifer Louise Fifer 03 Nov '21

03 Nov '21

From: Eberly, Megan R <meberly(a)purdue.edu> Sent: Wednesday, November 3, 2021 3:48 PM To: Chiang, Mung <chiang(a)purdue.edu>; Cadwallader, Teresa L <tlc3764(a)purdue.edu> Cc: Heath, Kathy M <heathk(a)purdue.edu>; bcaffery(a)ecn.purdue.edu; Nyquist, Chell E <nyquist(a)purdue.edu>; Cooper, Kitty R <kcooper(a)purdue.edu>; Williams, LeAnne E <lewillia(a)purdue.edu>; Carte, Lori J <ljcarte(a)purdue.edu>; Quirk, Carlene C <quirkc(a)purdue.edu>; Lindsay Marie Sellers <lseller(a)purdue.edu>; Jennifer Louise Fifer <fiferj(a)purdue.edu>; Luse, Teresa <tluse(a)purdue.edu>; Mikels, Dawn J <djmikels(a)purdue.edu>; Theobald, Katelynn J <kate(a)purdue.edu> Subject: 2 weeks left to make our goal!! Good Afternoon!! We are heading into the last 2 weeks of the 2021 Purdue United Way campaign and we need everyone's help as we wrap up and march towards our goal of $725,000. As a University we have pledged $438,379. Please join me in the fight and encourage faculty and staff to make their pledge and participate before Nov. 17! Online pledges can be made at www.purdue.edu/unitedway<http://www.purdue.edu/unitedway> College of Engineering plays an important part in the campus campaign. Your College has raised $36,920 toward a unit goal of $68,000. Thank you for the incredible support thus far! COME CELEBRATE WITH US! You're invited to join United Way of Greater Lafayette in celebrating the successes of our 2021 campaign! Each year at the end of our campaign season, we are thrilled to celebrate each and every contribution made to our community over the past few months. Join us on November 18th from 6 pm - 8 pm at the West Lafayette Golf and Country Club as our campaign leaders share the highlights and reveal the total dollars raised! To RSVP click HERE<https://uwlafayette.org/victory2021/?utm_source=Register+Button&utm_medium=…> to Register button below or call Janice Smith at 765-742-9077 ext. 235. We hope to see you there! This is free and open to anyone and everyone!!! Megan Eberly Office of Engagement m: 317-695-5740<tel:3176955740> meberly(a)purdue.edu<mailto:meberly@purdue.edu> www.purdue.edu/engagement <http://www.purdue.edu/engagement> [97D07221]<https://www.purdue.edu/>

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REMINDER: Final Exam Seminar, Nov. 2, Tuesday, at 12:00 (noon)
by Morgan, Yuan-Yu Karen 01 Nov '21

01 Nov '21

From: Morgan, Yuan-Yu Karen Sent: Thursday, October 21, 2021 8:46 AM To: msegradstudent-list(a)ecn.purdue.edu; msefaculty-list(a)ecn.purdue.edu; msepostdoc-list(a)ecn.purdue.edu Cc: Son, Rosemary E <son39(a)purdue.edu> Subject: Final Exam Seminar, Nov. 2, Tuesday, at 12:00 (noon) Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Data Driven Microstructural Design of Porous Electrodes" By Abhas Deva Purdue MSE Ph.D. Final Exam Advisor: R. Edwin García ABSTRACT Porous lithium ion battery (LIB) electrodes are comprised of electrochemically active material particles that store lithium and a surrounding conductive binder, liquid electrolyte, carbon black mixture that facilitates ionic and electronic transport. Typically, lithium diffusivity is several orders of magnitude smaller in the active material as compared to the surrounding electrolyte, making the electrode microstructure a governing factor in determining the balance between its lithium storage capacity and transport rate. Here, the effects of microstructure on the performance of LIBs are systematically analyzed at three length scales - the single particle length scale, the spatially resolved multiple particle length scale, and the porous electrode layer (homogenized) length scale. At the single particle length scale, a thermodynamically consistent variational framework is presented to examine the effects of crystallographic anisotropy, crystallographic texture, grain size, and grain morphology on the LiNi1/3Mn1/3Co1/3O2 (NMC111) chemistry. The theory was extended to the spatially resolved multiple particle length scale and the porous electrode layer length scale to explain the microstructural origin of experimentally observed instances of apparent phase separation in NMC111. At the electrode length scale, a data driven framework is presented to evaluate the electrochemical performance of a wide range of particle morphologies and battery architectures. Specifically, microstructural characteristics of 53 356 microstructures are assessed, and strategies to optimize electrode design parameters such as active particle morphology, spatial orientation, electrode porosity, and cell thickness are presented. Place: https://purdue.webex.com/purdue/j.php?MTID=md76713504103add582720df99d2bc8cb Time: Tuesday, Nov 2, 2021 12:00 pm | 1 hour | (UTC-04:00) Eastern Time (US & Canada) Meeting number: 2622 861 5362 Password: e2jCJ26N6b4 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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MSE 690 Nov 15 Karen Winey, ARMS 1010, 3:30 PM
by Ku Blanco, Aury Y 01 Nov '21

01 Nov '21

Good afternoon, Please mark your calendars and join us next Monday, Nov 15th when Prof. Karen Winey of UPenn<https://winey.seas.upenn.edu/> will be on campus to present in ARMS 1010 at 3:30 pm. [cid:image002.jpg@01D7CF1D.39DD61D0] Best, Aury Ku she/her/hers Administrative Assistant Materials Engineering Neil Armstrong Hall of Engineering 701 W Stadium Ave, ARMS 2300 West Lafayette, IN 47906 o: 765-494-4100 f: 765-494-1204

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