November 2018 - Msepostdoc-list

Seminar Reminder for Vignesh Vivekanandan's Preliminary Exam. Monday Nov. 26, at 10:30 a.m., in ARMS 1109
by Son, Rosemary E 26 Nov '18

26 Nov '18

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Review of dislocation junctions in FCC Metals" By Vignesh Vivekanandan Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Anter El-Azab ABSTRACT Plastic deformation of metals occurs by dislocation motion. The density of dislocations increase during plastic deformation giving rise to hardening. This process is controlled by dislocation-dislocation interaction, especially the so-called forest cutting and junction formation. In this review, the different types of junctions and their contribution to hardening in FCC metals are discussed. First, the junction formation process is explained based on linear elastic models of dislocations. Then the shortcomings of such models are discussed and the need for dislocation dynamics simulations is emphasized. Following that, different algorithms used to model and characterize junctions in dislocation dynamics are summarized. Based on the characterization, different ways of incorporating these effects into dislocation-based crystal plasticity models and continuum dislocation dynamics models are discussed. Date: Monday, November 26, 2018 Time: 10:30 A.M. Place: ARMS 1109

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Seminar Reminder for Vignesh Vivekanandan's Preliminary Exam. Monday Nov. 26, at 10:30 a.m., in ARMS 1109
by Son, Rosemary E 21 Nov '18

21 Nov '18

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Review of Junctions in FCC Metals" By Vignesh Vivekanandan Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Anter El-Azab ABSTRACT Plastic deformation of metals occurs by dislocation motion. The density of dislocations increase during plastic deformation giving rise to hardening. This process is controlled by dislocation-dislocation interaction, especially the so-called forest cutting and junction formation. In this review, the different types of junctions and their contribution to hardening in FCC metals are discussed. First, the junction formation process is explained based on linear elastic models of dislocations. Then the shortcomings of such models are discussed and the need for dislocation dynamics simulations is emphasized. Following that, different algorithms used to model and characterize junctions in dislocation dynamics are summarized. Based on this characterization, a methodology to incorporate the information in continuum models is explored. Date: Monday, November 26, 2018 Time: 10:30 A.M. Place: ARMS 1109

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Seminar Notice for Eduardo Barocio's Ph.D. Final Exam. Thursday, November 29, at 2:00 p.m., in IMI 130
by Son, Rosemary E 20 Nov '18

20 Nov '18

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Fusion Bonding of Fiber Reinforced Semi-Crystalline Polymers in Extrusion Deposition Additive Manufacturing" By Eduardo Barocio Purdue MSE Ph.D. Final Exam Advisor: Professor R. Byron Pipes ABSTRACT Extrusion Deposition Additive Manufacturing (EDAM) is a large-scale Additive Manufacturing (AM) technology able to fabricate parts from the desktop scale to the size of a full vehicle. Fiber reinforced polymers have been the primary enabler for this steep transition by reducing the thermal expansion and increasing the stiffness of printing materials. The EDAM process consists of depositing beads of molten material in a layer-by-layer manner, thus large temperature gradients develop during part manufacturing. Further, shear flow introduced during material extrusion and deposition orients fibers dominantly along the print direction. In the absence of fibers reinforcing the interface between adjacent layers, the bond developed by the polymer matrix is the primary mechanism governing the interlayer mechanical properties. The combination of residual stresses due to anisotropy and temperature gradients with weak interlayer bonding can lead to delamination of parts during manufacturing. Hence, there is a need for predictive simulation tools to mitigate the empirical process of determining printing strategies that lead to crack free parts. Significant contributions were made towards this objective by developing simulation tools for predicting the evolution of temperature and interlayer strength during part manufacturing. The continuous deposition of material is replicated virtually utilizing a framework developed previously for EDAM process simulation. A suite of user-defined subroutines in Abaqus(c) was utilized for implementing different mechanisms of heat transfer as well as a model for fusion bonding. Methods for characterizing not only the properties of printing materials for EDAM process simulations but also the processing conditions used in the EDAM process are presented. Additionally, the Composites Additive Manufacturing Research Instrument (CAMRI) was developed to investigate the physical phenomena dominating the EDAM process. Printed composite tooling for high-temperature autoclave and compression molding composites manufacturing has been the primary demonstrator for this technology. Date: Thursday, November 29, 2018 Time: 2:00 P.M. Place: IMI 130

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Seminar Notice for Francisco Montes' Ph.D. Final Exam. Tuesday, November 27, at 1:30 p.m., in the Graduate Student Center PGSC-105AB
by Son, Rosemary E 20 Nov '18

20 Nov '18

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Effects on Rheology and Hydration of the Addition of Cellulose Nanocrystals (CNC) in Portland Cement Pastes" By Francisco J. Montes Purdue MSE Ph.D. Final Exam Advisor: Professor Jeffery P. Youngblood ABSTRACT Cellulose Nanocrystals have been used in a wide range of applications including cement composites as a strength enhancer. This work analyses the use of CNC from several sources and production methods, and their effects on rheology and hydration of pastes made using different cement types with different compositions. Cement Types I/II and V were used to prepare pastes with different water to cement ratios (w/c) and measure the changes in rheology upon CNC addition. The presence of Tricalcium Aluminate (cement chemistry denotes as C3A) played an important role in the magnitude of CNC effects. At dosages under 0.5vol% relative to dry cement, CNC reduced the yield stress up to 50% the control value. Pastes with more C3A reduced yield stress over a wider range of CNC dosages. CNC also increased yield stress of pastes with dosages above 0.5%, twice the control value for pastes with high C¡A content at 1.5% CNC and up to 20 times for pastes without C¡A at the same dosage. All the CNCs used were characterized in length, aspect ratio, zeta potential to identify a definitive factor that governs the effect in the rheology of cement pastes. However, no definitive evidence was found that any of these characteristics dominated the measured effects. The CNC dosage at which the maximum yield stress reduction occurred increased with the amount of water used in the paste preparation, which evidences the dominance of the water to cement ratio in the rheological impact of CNC. Isothermal calorimetry showed that CNC cause concerning retardation effects in cement hydration. CNC slurries were then tested for sugars and other carbohydrates that could cause the aforementioned effect, then slurries were filtered, and impurities were detected in the filtrate, these impurities were quantified and characterized, however, the retardation appeared to be unaffected by the amount of the species detected, suggesting that the crystal chemistry, consequence of the CNC processing method, is responsible of this retardation. This work explores the benefits and drawbacks of the use of CNC in cement composites by individually approaching rheology and hydration on a range of physical and chemical conditions to build a better understanding of the observed effects can be achieved. Understanding the effect of CNCs on cement paste rheology can provide insights for future work of CNCs applications in cement composites. Date: Tuesday, November 27, 2018 Time: 1:30 P.M. Place: ARMS PGSC-105AB

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Seminar Notice for Sami El Awad Azrak's Preliminary Exam. Friday, Nov. 30, at 1:30 p.m., in ARMS 1028
by Son, Rosemary E 19 Nov '18

19 Nov '18

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Large Scale Processing of Mechanically Fibrillated Cellulose Nanofiber (CNF) Films" By Sami M. El Awad Azrak Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Jeffrey P. Youngblood ABSTRACT Driven by the invention of the first semi- and fully- synthetic polymers by John Wesley (1869) and Leo Baekeland (1907), and the need to preserve precious natural resources during World War II (1935), man-made polymer products have become vital components of our daily lives. Out of the many possible end products; polymeric films, sheets, and porous fabrics have seen large use in the packaging industry ($198 billion globally) and textile industry ($17 billion in the USA). In order to meet the current demand for synthetic polymer products (335 million metric tons of raw polymers produced in 2016) innovative large scale processing techniques have been developed. Some of the popular techniques used to process common engineering polymers (PE, PP, PET, etc.) into films and sheets include; extrusion, film blowing, melt/sheet casting, and calendaring. All of which take advantage of the formability and flowability of these polymers when heated above their glass and melting temperatures as well as the shear thickening or thinning behavior of the melt. Other techniques like carding, spunbonding, and the papermaking process are used to create bonded porous fabrics, also known as nonwovens, from man-made polymer fibers (Tencel, PP, PE, PET, PTT, Nylon 6,6) or naturally made fibers like cellulose. Yet, with an ever increasing need to replace and reduce the dependency on oil sourced polymers, degradable and sustainable polymers will need to be processed into similar useable forms. Additionally, these bio-friendly products will need to perform equally well or outperform common engineering polymers. Fibrillated cellulose, also known as microfibrillated cellulose (MFC) or cellulose nanofibers (CNF), is a perfect candidate to be processed into films due to its abundancy and sustainability. Furthermore, it has been shown that films produced from differently treated versions of MFC material have exceptional mechanical and optical properties which rival and surpass those found in common engineering polymers and even some metals like steel when considering its low density (~1.6 g/cm). Though extremely promising, the processing of CNF into films has lagged behind other polymers in industry. Techniques found in literature that can directly process this material remain largely semiautomatic and have very long lead times (from an hour to a couple of weeks). In order to further the efforts and help elucidate the processing of this novel material, common polymer processing techniques will be reviewed, as well as those used for nonwoven fabrics and the papermaking process. A comparison will be made between these techniques and those used to process pure CNF films. The challenges of processing CNF with current industrial techniques will be brought up and possible solutions will be proposed. Pilot scale plants that have successfully produced self-standing films will also be mentioned. Additionally, important parameters that affect the overall mechanical performance of CNF films will be discussed. Date: Friday, Nov. 30, 2018 Time: 1:30 P.M. Place: ARMS 1028

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Seminar Notice for Greg Scofield's Preliminary Exam. Wednesday, November 28, at 2:00, in HAMP 1252
by Son, Rosemary E 19 Nov '18

19 Nov '18

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Investigation into the Role of Oxidation on Static Fatigue Behavior of Siliconized Silicon Carbide" By Gregory C. Scofield Purdue MSE Ph.D. Preliminary Exam Advisors: Professor Kenneth Sandhage and Professor Michael Sangid ABSTRACT Silicon carbide based ceramics matrix composites (CMCs) seek to replace nickel superalloys in gas turbine components due to their comparatively low density and high strength at elevated temperatures, however, the introduction of these new composite materials can only be achieved after failure mechanisms are properly understood. Harsh combustion environments are known to decrease fatigue life of these composite materials, though the effect of oxidation on mechanical properties is still not fully understood, leading to unpredictable failure of components. A review of the current literature relating to static fatigue of siliconized silicon carbide is presented with emphasis given to oxidation mechanisms within the composite system. Gaps within literature are addressed and a plan for continued research into the effects of oxidation on static fatigue behavior in siliconized silicon carbide is proposed. Date: Wednesday, November 28, 2018 Time: 2:00 P.M. Place: HAMP 1252 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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Seminar Notice for Vignesh Vivekanandan's Preliminary Exam. Monday Nov. 26, at 10:30 a.m., in ARMS 1109
by Son, Rosemary E 19 Nov '18

19 Nov '18

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Review of Junctions in FCC Metals" By Vignesh Vivekanandan Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Anter El-Azab ABSTRACT Junctions are known to be responsible for the hardening behavior observed during plastic deformation in crystalline materials. In this review paper, the different types of junctions and their contribution to hardening is discussed. First, the junction formation process is explained based on linear elastic theories available in literature. Then their short comings and the need for DDD (Discrete dislocation dynamics) simulations is emphasized. Following that, different algorithms used to model junctions in DDD and the ways to characterize the junction formation process in DDD are summarized. Based on the characterization, the right way to incorporate the information in continuum models is explored. Date: Monday, November 26, 2018 Time: 10:30 A.M. Place: ARMS 1109

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REMINDER Today: Monday, November 19, at 3:30, in ARMS 1010 / MSE 690 Speaker Glenn S. Daehn, Ph.D. - Impulse Manufacturing: Why and How
by Coar, Stacey L 19 Nov '18

19 Nov '18

Please join us Monday, November 19th, to see Dr. Glenn Daehn speak in MSE 690 at 3:45. Thank you, Stacey [cid:image001.png@01D47FE3.8A2E4960]

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Seminar Reminder for Lucas Robinson's Preliminary Exam. Seminar Friday, Nov. 16, at 11:30 a.m., in ARMS 3115; Review from 12:30 - 1:00, in ARMS 2326; Exam at 1:00, in ARMS 2326
by Son, Rosemary E 15 Nov '18

15 Nov '18

Please consider attending the following: Please also see correction-the seminar is Nov. 16, at 11:30 a.m., in ARMS 3115 MATERIALS ENGINEERING SEMINAR "Field Microstructure Evolution of Solid-Solid Interfaces in Ionic Ceramics for Energy Applications" By Lucas D. Robinson Purdue MSE Ph.D. Preliminary Exam Advisor: Professor Edwin García ABSTRACT Interfaces (grain boundaries, phase boundaries, surfaces, etc.) can greatly influence the performance of energy-related materials. Applications where interfaces play a critical role include solid state batteries and solid oxide fuel cells, electronic materials, metallic vias, and solder bumps that connect different components. These bonded material systems possess equilibrium and kinetic properties that can be attributed to the underlying interfaces due to the interactions between abutting phases, with dissimilar properties. In this context, understanding the evolution of the heterostructural phases that develop is a key step for the development of advanced devices. In this work, phase field models for the microstructure evolution of homo- and heterointerfaces are reviewed. Current models in literature are found to be insufficient for modeling phase boundaries in battery materials, and do not fully describe a multiphase, multicomponent system with charge and polarization effects. A generalized multiphase field theoretical framework is being developed to predict the effects of interfacial space charge, composition, and lattice mismatch on through-thickness transport properties for ceramic systems. Application of the model for microstructure evolution in metallic systems is discussed as a stepping stone for its use in battery materials. Date: Friday, November 16, 2018 Time: 11:30 A.M. Place: ARMS 3115

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Install filtered water bottle-filling stations in ARMS - petitioning Dean Chiang
by Coar, Stacey L 14 Nov '18

14 Nov '18

All, My name is Andrew Binder and I am a College of Engineering Ambassador. The College of Engineering Ambassadors have recognized that there is a need for filtered water bottle-filling stations in Armstrong Hall. This survey intends to gauge support from students to get water bottle-filling stations installed in Armstrong Hall and, ultimately, to produce a list of student and faculty signatories to the petition that is written. The College of Engineering's Dean, Dr. Mung Chiang, has initiated a number of projects to improve student quality-of-life. Hopefully, with your support, we can also highlight the merits of this quality-of-life improvement. Your signatures, among other data, will be used to build a case for this suggestion to ultimately be implemented. Please note that you can take this survey anonymously if you choose, but there is an option to list your email as a signer to this petition within the survey. Please fill out this option if you would like to be listed on the list of signatories presented to Dean Chiang. https://purdue.ca1.qualtrics.com/jfe/form/SV_9tXaar67mhQYk4J Please direct any questions to my e-mail, binder1(a)purdue.edu<mailto:binder1@purdue.edu>. Thank you for your consideration and support! Andrew Binder AAE, Class of 2019 CoE Ambassadors

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