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Correction: MSE 690 Nov 12 John Lewandowski - Nov 15 details inside
by Ku Blanco, Aury Y 10 Nov '21

10 Nov '21

Correction: Last e-mail's subject line incorrectly read Nov 15 instead of Nov 12 - please do join us on Monday, Nov 15th for Prof. Karen Winey's<https://winey.seas.upenn.edu/> visit at 3:30 PM in ARMS 1010. Thanks, Aury From: Ku Blanco, Aury Y Sent: Wednesday, November 10, 2021 9:31 AM To: msegradstudent-list(a)ecn.purdue.edu; msepostdoc-list(a)ecn.purdue.edu; msefaculty-list(a)ecn.purdue.edu; msecourtesy-list(a)ecn.purdue.edu Cc: Stanciu, Lia A <lstanciu(a)purdue.edu>; Titus, Michael S <titus9(a)purdue.edu> Subject: CANCELED: MSE 690 Nov 15 John Lewandowski Good Morning, This Friday's MSE 690 seminar with Prof. John Lewandowski is canceled. Apologies for any inconvenience. Thank you, 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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CANCELED: MSE 690 Nov 15 John Lewandowski
by Ku Blanco, Aury Y 10 Nov '21

10 Nov '21

Good Morning, This Friday's MSE 690 seminar with Prof. John Lewandowski is canceled. Apologies for any inconvenience. Thank you, 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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Job opportunity at a startup in Chicago
by Morgan, Yuan-Yu Karen 09 Nov '21

09 Nov '21

Dear Graduate Students and Postdocs, Celadyne Technologies, Inc is a startup currently based in Chicago and associated with Argonne National Lab and is funded through the DoD, DoE, NSF and the Breakthrough Energy Coalition (Bill Gates' climate coalition). They are currently looking for two great candidates who are interested in working in a fast paced startup environment on new fuel cell technologies. Good luck with your application! Postings here: https://www.indeed.com/viewjob?t=senior+engineer&jk=05a13a719ea9fa43&_ga=2.… https://www.indeed.com/viewjob?t=engineer&jk=1862ddf0846e436c&_ga=2.1342218… Boiler Up, Dr. Morgan 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 John Lewandowski, ARMS 1010, 3:30 PM
by Ku Blanco, Aury Y 09 Nov '21

09 Nov '21

Hi all, Please join us this Friday at 3:30 PM in ARMS 1010 for Prof. John Lewandowski<https://case.edu/issacs/faculty-associates/john-lewandowski>'s presentation on the Advanced Manufacturing and Mechanical Reliability Center<https://ammrc.case.edu/> at Case Western University. [cid:image001.jpg@01D7D582.E14B9250] Thank you, 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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Final Exam Seminar, Monday, Nov. 22, at 1:30 pm at HAMP 1266
by Morgan, Yuan-Yu Karen 08 Nov '21

08 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Design and Processing of NiCo-based Superalloys for the Study of Solute Segregation at Planar Defects During High Temperature Deformation" By Sae Matsunaga Purdue MSE Ph.D. Final Exam Advisors: Professor Michael Titus ABSTRACT Ni-based superalloys have been widely used for high temperature applications such as turbine blades for jet propulsion and power plants due to their excellent creep, fatigue, and corrosion resistance. But as the demand for higher temperature capability and strength increases, there remains a need to better understand high temperature deformation mechanisms and improve and strengthen superalloys at these elevated temperatures. Recently, a correlation has been observed between solute segregation at planar defects (stacking faults, antiphase boundaries, etc) and enhanced high temperature creep properties - known colloquially as phase transformation strengthening. Experimentally, regardless of alloy composition, strong Co segregation at planar defects along with Cr has been observed. In addition, it has been suggested by density functional theory work that Co would promote Cr concentration at stacking faults by forming strong Cr-Co bonds. Based on these findings, it was hypothesized the presence of Co provides a significant thermodynamic driving force for segregation to planar defects. In order to further investigate the correlation between solute segregation and deformation mechanisms the fabrication of a planar front single crystal Ni-based superalloy and its microstructure, alloy composition, and microhardness properties of the as-zone melted and solution heat treated states were investigated and compared to the directionally-solidified state to study the effect of microsegregation on these alloy characteristics. Next, new Co-containing, Cr-free alloys are designed to optimize gamma-gamma' volume fraction, size, and morphology to mimick microstructures observed in single crystal superalloys. The general alloy design strategy and approach are outlined, and the composition, microstructure, phase transformation temperatures, and mechanical properties of new Cr-free and Co-containing alloys are reported. A new set of Cr-free alloys have thus been designed, with modifications of Nb, Ta, and Ti additions ranging from 3 to 7 at.% to investigate the role of these elements on the phase transformation strengthening mechanism at elevated temperatures. Date: Monday, November 22, 2021 Time: 1:30 P.M. Place: HAMP 1266 or Join from the meeting link https://purdue.webex.com/purdue/j.php?MTID=mf23fce9475ea4d01fefa71ab1edf8013 PURDUE MSE [cid:image002.png@01D7D4C0.5C6CEA10]

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Preliminary Exam Seminar, Monday, Nov 22 at 9 AM by Webex
by Morgan, Yuan-Yu Karen 08 Nov '21

08 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Role of Surface Energy on the Growth of Vertically Aligned Nanocomposite Thin Films" By Jiawei Song Purdue MSE Preliminary Exam Advisor: Professor Haiyan Wang ABSTRACT Vertically aligned nanocomposite (VAN) thin films are widely explored due to their ability to couple different functionalities and induce three-dimensional strain. Several material systems have been studied include oxide-oxide, oxide-metal, and nitride-metal systems. Thermodynamic analysis of the nucleation and growth process is needed to understand the growth mechanism of self-assembled VAN structure. Thin film growth is affected by multiple factors, such as surface energy, lattice strain, crystal structure, and composition ratio. This review discusses how surface energy affects the growth of VAN thin films and proposes a design guideline for exploring new material systems. Date: Nov 22, 2021 Time: 9:00 AM WebEx: https://purdue.webex.com/purdue/j.php?MTID=m212b44464e40df23ee6c87a4c9fe62eb

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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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