November 2017 - Msepostdoc-list

Fwd: Condensed Matter Seminar
by Donna Bystrom 30 Nov '17

30 Nov '17

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Seminar Notice for Chia-Hsiu (Hugh) Chang's Preliminary exam. Seminar, Thursday, Dec. 7, at 12:00, in HAMP 2107; Exam is at 1:30, in ARMS 2009. "Solid-Solution Strengthening in FCC Complex, Concentrated Alloys"
by Son, Rosemary E 30 Nov '17

30 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Solid-Solution Strengthening in FCC Concentrated Complex Alloys" By Chia-Hsiu Chang Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Michael S. Titus ABSTRACT Concentrated complex alloys (CCAs) were recently proposed as a novel class of new alloys, and they are defined as alloys composed of four or more alloying elements without a majority concentration or "base" element, for example Co1Fe1Mn1Ni1. Oftentimes, researchers aim to synthesize CCAs exhibiting a single solid-solution phase (e.g. fcc or bcc) because of the significant solid-solution strengthening provided by the high concentration of many solute elements. Early research revealed that, in some case, these alloys exhibit comparable yield strength to precipitation-strengthened alloys over a large temperature range. However, the strengthening mechanisms of CCAs are not clear at present. Despite the significant historical effort to understand solid-solution strengthening in random alloys, conventional theory is unable to quantitatively predict yield strength as a function of temperature and strain rate in multi-solute, non-dilute solid-solution alloys. A new theory for predicting the yield strength of fcc CCAs has recently developed, and comparisons between predicted and experimental results based on the new model will be discussed. Because the model requires complete knowledge of the material properties for each alloying element, we seek to simplify the model in order to understand additions of a single solute to a given CCA composition. The study hypothesizes that CCAs could be treated as pseudo-binary alloys, in which the "solvent" is a given CCA and the solute is the final alloying element. A brief outline of the proposed research plan to validate and improve on the current model for predicting CCA strength will be presented Date: Thursday, December 7, 2017 Time: 12:00 P.M. Place: HAMP 2107

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Final Agenda: MSE 690 Seminar Speaker Dr. Ellen Cerreta, Friday, December 1, 2017 ARMS 1010 3:30 pm
by Coar, Stacey L 30 Nov '17

30 Nov '17

Good morning, Attached is the agenda and abstract for Dr. Ellen Cerreta. If you have any questions, please feel free to contact me. If you would like to be added to an already scheduled meeting just send me an email. Thank you, [cid:image002.png@01D369C0.36F2B770] [cid:image001.png@01D369BF.E9A8F330] Stacey Stacey Coar Secretary/Development Assistant School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2300 West Lafayette, IN 47907 765-494-4100 scoar(a)purdue.edu<mailto:scoar@purdue.edu>

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Reminder for Seminar for Jorge A. Ramirez's Preliminary Exam on Dec. 1, at 8:00 a.m., in IMI 127; Exam at 10:00 a.m., in IMI 127 "Voids and Continuous Fibers in Extrusion Deposition Additive Manufacturing of composite Materials"
by Son, Rosemary E 30 Nov '17

30 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Voids and Continuous Fibers in Extrusion Deposition Additive Manufacturing of Composite Materials" By Jorge A. Ramirez Purdue MSE Ph.D. Preliminary Exam Advisor: Professor R. Byron Pipes ABSTRACT Extrusion Deposition Additive Manufacturing (EDAM) is a layer-by-layer three-dimensional manufacturing process. This process consists of the liquefaction and pressurization of pelletized material inside an extruder, the material melt is then deposited onto a build platform to create a physical object. The incorporation of an extruder allows EDAM to process a wide range of materials. The Composites Manufacturing and Simulation Center (CMSC) at Purdue has explored the use of this technology with highly filled polyphenylene sulfide (PPS) with carbon fibers (50 wt%) for composites tooling applications. Advantages of EDAM in tooling manufacturing include reductions in lead time and cost. In addition, EDAM allows for a high degree of customization and optimization. Properties of EDAM parts are directly dependent on their final microstructure. In this work, I discuss two key microstructural features, voids and fiber orientation state, and how they are dictated by different processing parameters. Lastly, I discuss the implementation of reinforcing continuous fibers with EDAM for rapid fabrication of structural components. Date: Friday, December 1, 2017 Time: 8:00 A.M. Place: IMI 127 School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2200 West Lafayette, IN 47907 765-494-4105

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Fwd: Condensed Matter Seminar
by Donna Bystrom 30 Nov '17

30 Nov '17

Please join us in welcoming Condensed Matter seminar speaker Professor Alex Norquist. The seminar will be held on: Friday, December 1, 2017 3:30 PM – 4:30 PM PHYS Room 203 Please see attached for more information. Thank you.

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Seminar Notice for Yen-Yu (Winston) Chen's Preliminary Exam. Seminar, Tuesday, Dec. 5, at 1:30 p.m., in ARMS 1109; Exam same day at 3:00 in ARMS 2237. "Flexible Gas Sensors for Monitoring Volatile Organic Compounds"
by Son, Rosemary E 29 Nov '17

29 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Flexible Gas Sensors for Monitoring Volatile Organic Compounds" By Yen-Yu Chen Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Lia A. Stanciu ABSTRACT Two-dimensional (2D) transition metal dichalcogenides (TMDCs) are considered as a new class of sensing materials because of their flexible layered structure, high specific surface area, and good semiconducting properties. A gas sensor capable of operating at room temperature is appealing because it requires a simple fabrication process and low power consumption. Herein, a review of various sensing materials, metal-oxide semiconductors, carbon-based materials, and TMDCs, for the detecting features of different life-affecting and environment-impacting gases, including volatile organic compounds (VOCs), inorganic gases (NH3 and NO2), and ethylene, will be presented. Then, the fabrication methods of TMDCs, particularly 2D MoS2 (layered nanoflake), will be introduced. These reviews suggest that (a) LPE is one of most promising cost-effective methods to synthesize 2D TMDC gas-sensing materials in a mass-production manner and (b) surface modification is required for TMDCs to detect gases effectively at room temperature. Indeed, preliminary research results indicate that the gas sensors made of Au-decorated LPE-MoS2 exhibit superior ability to sense extremely low concentrations of VOCs at room temperature. A series of LPE-TMDCs will be further studied for the development of high-performance, room-temperature gas sensors. Date: Tuesday, December 5, 2017 Time: 1:30 P.M. Place: ARMS 1109

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Seminar Notice for Sathish Kumar Ranganathan's Prelim. Seminar, Tuesday, Dec. 5, at 9:30 in HAMP 1266; Exam same day, at 1:30, in ARMS 3001 "Durable Icephobic Coatings for Aluminum Substrates"
by Son, Rosemary E 29 Nov '17

29 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Durable Icephobic Coatings for Aluminum Substrates" By Sathish Kumar Ranganathan Purdue MSE Ph.D. Preliminary Exam Advisors: Professors Jeffery P. Youngblood and John A. Howarter ABSTRACT Development of durable ice-phobic coatings and mitigation of ice accumulation on solid surfaces has proven to be a challenging task in the past decade. Considering the current limitations to the state of the art, development of durable superhydrophobic surfaces which could deliver less ice accretion and low ice adhesion strength is an important research milestone. Improving experimental understating of ice phobic performance, such as the correlation between ice adhesion strength and ice removal conditions, as well as the role of surface wetting properties to the rate of ice accumulation would be quite valuable. Therefore, highly durable Fluoro-Ethylene-Alkyl-Vinyl-Ether (FEVE) based slippery and superhydrophobic coating will be developed to study its durability at extreme ageing conditions and retention of icephobic performance will be validated to understand potential benefits for industrial applications. Date: Tuesday, December 05, 2017 Time: 9.30 A.M. Place: HAMP 1266

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MSE 690 Seminar Speaker Dr. Brian Bennett, Monday, December 4, 2017 ARMS 1010 3:30 pm
by Coar, Stacey L 28 Nov '17

28 Nov '17

Good afternoon, We have another MSE 690 guest speaker visiting on Monday, December 4. Dr. Brian Bennett, Program Officer for Electromagnetic Materials Office of Naval Research. Please see his attached abstract, I hope to see you all there. [cid:image001.png@01D3685D.43D6E380] Stacey Stacey Coar Secretary/Development Assistant School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2300 West Lafayette, IN 47907 765-494-4100 scoar(a)purdue.edu<mailto:scoar@purdue.edu>

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Seminar Notice for Indrani Biswas's Preliminary Exam, Monday, Dec. 4, at 12:30 p.m., in ARMS 3115, Exam Dec 4, at 2:00, in ARMS 2009. " Analysis of Sample Size Effects on Strength of Metals and Alloys Through Micropillar Compression Testing"
by Son, Rosemary E 28 Nov '17

28 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Analysis of Sample Size Effects on Strength of Metals and Alloys Through Micropillar Compression Testing" By Indrani Biswas Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Kevin P. Trumble ABSTRACT Yield strength of metals and alloys has long been known as a material property with little or no dependence on specimen size. However, through micropillar compression testing (MCT) it was revealed that, strength of micron-sized single crystal pillars was much larger than of bulk specimens and scaled with the pillar diameter. The paper analyses the theory of dislocation starvation; which assumes increased dislocation annihilation from sample surface as the reason for such high strengths. It was found that the model predicts near zero dislocation densities shortly after the onset of plasticity which is unrealistic. Polycrystals under MCT showed unexpected weakening when the sample size was few times the grain diameter. Two competing theories for weakening have been compared. The first attributes it to occurrence of grain boundary sliding and the second assumes that surface grains provide lower resistance to dislocation motion than those in the interior. Higher fraction of surface to bulk grains in smaller samples is probably responsible for the loss in strength. The analysis presented was that since surface grains are under less constraint, they are also more prone to sliding. So, the weakening can be a combined effect of the two mechanisms. Simulation of polycrystal deformation with different surface to volume ratio was suggested to validate the hypothesis. Date: Monday, December 4, 2017 Time: 12:30 P.M. Place: ARMS 3115

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Seminar Notice for Pilsun Yoo's Preliminary Exam, Seminar, Dec. 4, at 9:30 a.m., in HAMP 2123, and Exam, 11:00 a.m., in ARMS 2007. " First Principle Study for NO Oxidation in Perovskite Oxide"
by Son, Rosemary E 28 Nov '17

28 Nov '17

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "First Principle Study for NO Oxidation in Perovskite Oxide" By Pilsun Yoo Purdue MSE Ph.D. Preliminary Exam Advisor: Peilin Liao ABSTRACT Among composition of emission gas, NOx (x = 1, 2) is abundant and environmentally damaging molecule with operation of diesel engines which is associated with acid rain, smog, and ozone depletion. To decompose NOx (x = 1, 2), Pt-based catalyst demonstrated highest conversion rate for NOx decomposition in NOx storage and reduction (NSR) process. Recently, La based perovskite comes into the spotlight for an alternative catalyst due to several disadvantages of Pt-based catalyst such as high cost, thermal instability, aging effect and surface oxidation under operation condition. The NO oxidation property of La based perovskite catalysts was observed to be highly dependent on different transition metals in B site and substitution of La in LaBO3. In particular, it was noted that the oxygen vacancies driven by substitution and doping of other elements were related to the conversion rate. However, the role of oxygen vacancies on NO oxidation process was not explicitly known in previous studies. In this regard, understanding the reaction mechanism should precede to further suggest promoted and optimized alternative catalysts. This study will make it possible to suggest optimized compositions based on the understanding on the mechanism related to lattice oxygen vacancies. Date: Monday, December 4, 2017 Time: 9:30 A.M. Place: HAMP 2123

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