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Seminar Notice for Anneliese Brenner's Ph.D. Final Exam Friday, April 12, at 8:30 a.m., in HAMP 2118. "Microstructural Investigations of Sm-Doped ZrB2 for Hypersonic Applications"
by Son, Rosemary E 05 Apr '19

05 Apr '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Microstructural Investigations of Sm-Doped ZrB2 for Hypersonic Applications" By Anneliese E. Brenner Purdue MSE Ph.D. Final Exam Advisor: Professor Rodney W. Trice ABSTRACT Sharp leading edges required for hypersonic vehicles improve the maneuverability as well as reduce aerodynamic drag. However, due to the sharp design, increased surface temperatures require materials that can withstand these extreme conditions. Ultra-high temperature ceramics are a material group being considered for the leading-edge material, specifically ZrB2/SiC (ZBS) which has a high thermal shock resistance, melting temperature, and thermal conductivity. Studies done by Tan et. al. has shown that adding samarium (Sm) as a dopant to ZBS has an emittance of 0.9 at 1600oC and develop oxide scales that have excellent ablation performance. However, it remained unknown how the Sm doped oxide scale formed as well as how the emittance and ablation performance are affected by the microstructure. This study investigates the oxide scale development of 3 mol% doped Sm-ZBS billets as well as how differences in microstructure affect the emittance and ablation performance. Samples were prepared via chemical infiltration of samarium nitrate into spray-dried powders of 80 vol.% ZrB2/20 vol.% SiC; powders were then pressed into billets and pressureless sintered. Samples cut and polished from these billets were then oxidized for 10, 60, or 300 s, respectively, using an oxyacetylene torch. X-ray diffraction was used to determine the sequence of oxidation of Sm-ZBS, beginning with the formation of ZrO2 and Sm2O3. The final oxide scale was determined to be c1-Sm0.2Zr0.8O1.9, with a melting temperature exceeding 2500oC. SEM and EDS were also used to investigate the microstructural formation that occurs from the bursting of convection cells. Samples with different microstructures revealed similar topographical microstructures post-ablation due to the sequence of the oxide formation. However, samples with rougher surfaces and higher porosities had a higher concentration of trapped glass in the cross-sectional oxide scale. It was also found that due to differences in heating the sample during emittance testing, the oxide developed was the same for all the samples. It was also found that differences in microstructure had no effect on the spectral emittance of Sm-ZBS at ultra-high temperatures. The fabrication of c1-Sm0.2Zr0.8O1.9 (SZO) as a bulk billet was also investigated to use as a thermal barrier coating (TBC) in replacement of Sm-ZBS. Date: Friday, April 12, 2019 Time: 8:30 A.M. Place: HAMP 2118

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Seminar Reminder for Angel Pena's Ph.D. Final. Thursday, April 4, at 9:00 a.m., in ARMS 3115. "Evaluation of Rare-Earth Element Dopants (Sm and Er) Effect on the Ablation Resistance and Emittance Tailoring of ZrB2/SiC Sintered Billets"
by Son, Rosemary E 03 Apr '19

03 Apr '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Evaluation of Rare-Earth Element Dopants (Sm and Er) Effect on the Ablation Resistance and Emittance Tailoring of ZrB2/SiC Sintered Billets" By Angel Antonio Pena Purdue MSE Ph.D. Final Exam Advisor: Professor Rodney W. Trice ABSTRACT Hypersonic flight causes ultra-high surface temperatures which are most intense on sharp leading edges. One way of reducing the surface temperature is to apply a high emittance ceramic on the leading edge, increasing the radiation component of heat transfer. An ideal HEC must have a high emittance, while also possess a strong ablation resistance. From a scientific standpoint, it would be helpful if emittance could be tailored at different wavelengths. The approach used to create a ceramic with tailorable emittance was the use two different rare-earth elements, adding them to a ultra-high temperature ceramic (UHTC) in small quantities. The samarium element was added to increase the emittance of the UHTC over a large wavelength range, and the erbium element was added to decrease the emittance at specific wavelength ranges. The goal of this study was to create an UHTC with tailorable emittance while maintaining the required ablation resistance. Therefore, ZBS billets with five different Sm to Er ratios and with a nominal total amount of 3 mol.% dopant incorporated were prepared by sintering in vacuum to 2000 °C. The ablation resistance was evaluated by using an oxyacetylene torch and observing at exposure times of 60s and 300s, whereas the emittance was evaluated at the Air Force Research Lab facilities via a laser heating testing. The results for the ablation testing showed that ZBS billets co-doped with Sm and Er formed a beneficial c1-(Sm/Er)0.2Zr0.8O1.9 oxide scale as the majority phase, which is more thermally stable than the m-ZrO2 oxide scale typically formed in oxidized ZBS systems. The crystalline and the amorphous phases were formed by a convection cell mechanism. Differences in surface temperatures between ZBS samples with different dopant ratios suggest differences in spectral absorptance/emittance between each of the five compositions evaluated. Despite the emittance profiles by varying the Sm:Er molar ratios were similar because m-ZrO2 was formed as the major oxide phase, the emittance study showed that the erbium oxide influences the emittance profile, as can be noted by the maximum and minimum emittance peaks. Results showed that the emittance changes as a function of the Sm:Er molar ratios and temperature at shorter wavelength ranges. These changes in the emittance are caused by the different Sm and Er concentrations on the surface. Future work should be focused on producing the beneficial c1-(Sm/Er)0.2Zr0.9O1.8 phase directly from the manufacturing process, and therefore, maximize the effect of varying the Sm:Er molar ratios to tailor the emittance. This study represents the first generation and reported emittance data of UHTC doping ZBS systems with both Sm and Er elements. Date: Thursday, April 4, 2019 Time: 9:00 A.M. Place: ARMS 3115

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MSE Seminars on 4/26/19
by Coar, Stacey L 03 Apr '19

03 Apr '19

Good morning, We have two seminars coming up on April 26th. I just want to give everyone a heads up since it is going to be a busy month. Please put these on your calendar. [cid:image003.png@01D4EA06.51DD54B0][cid:image004.jpg@01D4EA06.51DD54B0] 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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MSE Student Night April 25, 2019, Please Respond
by Coar, Stacey L 02 Apr '19

02 Apr '19

Good afternoon, There is still plenty of time to sign up for this year’s MSE Student Night on April 25th from 6:30 – 8pm. This event is a great opportunity to network with your peers, industry professionals, faculty and staff, and food will be provided. This is also a great opportunity to see this year’s senior design posters and the press boxes at Ross-Ade! RSVP at MSE student night 2019 survey<https://purdue.ca1.qualtrics.com/jfe/form/SV_bHkvgdmw35UcSI5> by April 11th if you have not taken the survey. Important Info: · RSVPS are required (even for seniors) · Business attire, photos will be taken with Sponsors · Student and Faculty award presentations will be presented during the program [cid:image001.jpg@01D4D8B0.7F452A70] 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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FW: CCO professional development offerings
by Son, Rosemary E 01 Apr '19

01 Apr '19

(A) AAUW StartSmart Salary Negotiation Workshop for graduate women Scheduled on April 2, 2019 from 5 - 7 PM in KRAN G013. Read details and register here<https://gspd.gosignmeup.com/public/Course/browse?courseid=2716>. (B) CCO Job Search Series for Grad Students This 4-part "Job Search Series" will walk you through most of the job or internship search process: personal branding, document development, networking & interviewing. You can stay back after the 45-min. small-group workshops for one-on-one feedback.* Apr. 3: Personal brand: what are you known for? For an effective job search, candidates should have a coherent personal brand. Learn key components of a successful brand, how to develop your own, & learn how to manage & communicate it in different contexts (in person, online). Apr. 10: Resumes & cover letters Learn what makes a resume compelling, & how to write impactful cover letters. Bring a resume & job posting to work on. Apr. 17: Networking (online & in person) Learn effective strategies, including informational interviews, social media usage, & follow-up. Apr. 24: Interviewing Learn how to accomplish both goals of an interview: marketing yourself effectively, & learning as much as you can about the company. We will also discuss how to answer visa-related, salary-related, & inappropriate/illegal questions. All 'Job Search Series' workshops: RAWLS 2097 from 4:15 to 5 PM NO RSVP needed; arrive early to get a seat! Room seats 30. Questions? askCCO(a)purdue.edu<mailto:askCCO@purdue.edu> * 5 to 6 PM: CCO drop-in hour. You can stay back for one-on-one feedback after the workshop is completed. Sign up when you arrive; limited spots available. If requesting a document review (CV, resume, cover letter), please bring a print out. Only one document per student. Please direct all questions about these events to me. Thank you for your help in advertising these opportunities. Amruta Amruta Inamdar, Ph.D. Career Services Consultant - Graduate Students Purdue University Center for Career Opportunities; YONG 245 amruta(a)purdue.edu<mailto:amruta@purdue.edu>; 765-494-1409 LinkedIn<https://www.linkedin.com/in/amruta-inamdar/>, Twitter<https://twitter.com/GradProfCareers> & Facebook<https://www.facebook.com/PurdueGradCareers/> My Office is a Safe Space [PU150CO_YRS_H_BG_RGB]<https://takegiantleaps.com/>

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Seminar Notice for Angel Pena's Ph.D. Final. Thursday, April 4, at 9:00 a.m., in ARMS 3115. "Evaluation of Rare-Earth Element Dopants (Sm and Er) Effect on the Ablation Resistance and Emittance Tailoring of ZrB2/SiC Sintered Billets"
by Son, Rosemary E 25 Mar '19

25 Mar '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Evaluation of Rare-Earth Element Dopants (Sm and Er) Effect on the Ablation Resistance and Emittance Tailoring of ZrB2/SiC Sintered Billets" By Angel Antonio Pena Purdue MSE Ph.D. Final Exam Advisor: Professor Rodney W. Trice ABSTRACT Hypersonic flight causes ultra-high surface temperatures which are most intense on sharp leading edges. One way of reducing the surface temperature is to apply a high emittance ceramic on the leading edge, increasing the radiation component of heat transfer. An ideal HEC must have a high emittance, while also possess a strong ablation resistance. From a scientific standpoint, it would be helpful if emittance could be tailored at different wavelengths. The approach used to create a ceramic with tailorable emittance was the use two different rare-earth elements, adding them to a ultra-high temperature ceramic (UHTC) in small quantities. The samarium element was added to increase the emittance of the UHTC over a large wavelength range, and the erbium element was added to decrease the emittance at specific wavelength ranges. The goal of this study was to create an UHTC with tailorable emittance while maintaining the required ablation resistance. Therefore, ZBS billets with five different Sm to Er ratios and with a nominal total amount of 3 mol.% dopant incorporated were prepared by sintering in vacuum to 2000 °C. The ablation resistance was evaluated by using an oxyacetylene torch and observing at exposure times of 60s and 300s, whereas the emittance was evaluated at the Air Force Research Lab facilities via a laser heating testing. The results for the ablation testing showed that ZBS billets co-doped with Sm and Er formed a beneficial c1-(Sm/Er)0.2Zr0.8O1.9 oxide scale as the majority phase, which is more thermally stable than the m-ZrO2 oxide scale typically formed in oxidized ZBS systems. The crystalline and the amorphous phases were formed by a convection cell mechanism. Differences in surface temperatures between ZBS samples with different dopant ratios suggest differences in spectral absorptance/emittance between each of the five compositions evaluated. Despite the emittance profiles by varying the Sm:Er molar ratios were similar because m-ZrO2 was formed as the major oxide phase, the emittance study showed that the erbium oxide influences the emittance profile, as can be noted by the maximum and minimum emittance peaks. Results showed that the emittance changes as a function of the Sm:Er molar ratios and temperature at shorter wavelength ranges. These changes in the emittance are caused by the different Sm and Er concentrations on the surface. Future work should be focused on producing the beneficial c1-(Sm/Er)0.2Zr0.9O1.8 phase directly from the manufacturing process, and therefore, maximize the effect of varying the Sm:Er molar ratios to tailor the emittance. This study represents the first generation and reported emittance data of UHTC doping ZBS systems with both Sm and Er elements. Date: Thursday, April 4, 2019 Time: 9:00 A.M. Place: ARMS 3115

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REMINDER Today: MSE 690 Seminar Speaker - Sunghwan Lee, Ph.D., Monday, March 25, 2019/ARMS 1010 - 3:45
by Coar, Stacey L 25 Mar '19

25 Mar '19

[cid:image001.jpg@01D4E2EA.70F7CE20] 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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Keys found
by Coar, Stacey L 22 Mar '19

22 Mar '19

Good afternoon, There was a set of keys found and turned into the Main MSE desk, if they are yours please come and get them :) 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: MSE 690 Seminar Speaker - Sunghwan Lee, Ph.D., Monday, March 25, 2019/ARMS 1010 - 3:45
by Coar, Stacey L 22 Mar '19

22 Mar '19

Good morning, Dr. Sunghwan Lee will be here on Monday, March 25 to give a seminar for MSE 690 at 3:45 in ARMS 1010. Please join us. [cid:image001.jpg@01D4E09C.4BCF16D0] 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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Safety Update: Lab coats, Self-Audit Checklists, LOTO training
by MSE Safety 21 Mar '19

21 Mar '19

Dear Graduate Students and Postdoctoral Researchers, I have a few safety items to update you all about... Item 1: Lab Coats Thank you all for complying with our new policy of wearing lab coats in CHP lab spaces. I know many of the lab supervisors have also installed garment racks for you to use for storing your coats (since your coats should NOT be stored in your offices) and this is great. To help those of you who use the ARMS second-floor polishing lab (ARMS 2132), there is now a garment rack next-door in the optical lab (ARMS 2130) for you to store your lab coat. Additionally, there is a new supply of shared-use lab coats on the rack which you may choose to use when you are working in the polishing lab. Current lab coat sizes are M-XXL but I have also ordered X and XS which should arrive shortly. Item 2: Self-Audit Checklists Thanks to everyone who helped with our annual safety inspection process by completing a Self-Audit Checklist for your lab spaces within ARMS and MSEE. I wanted to let you know that you are encouraged (but not required) to complete one of these checklists, at any time, for any lab space that you work in that is affiliated with Purdue - including shared-use labs in Birck, Bindley, IMI, Zucrow, Physics, FLEX, etc. Once completed, you should scan and email the checklist to mse-safety(a)purdue.edu and I will pass it on to REM. This is a particularly useful way to communicate any concerns you have about a given space to the MSE Safety Committee as well as REM. Attached is a blank self-audit checklist for your use . Item 3: Lockout/Tagout Training (LOTO) Extra caution and special procedures must be followed when performing any service or maintenance on electrical equipment within our lab spaces, including furnaces, mills, and mechanical equipment. To perform these tasks in a safe manner, Purdue employees must undergo LOTO Training and become authorized by REM to perform these kinds of tasks. If you currently do any significant maintenance or service on equipment within your lab space, you should talk to your research advisor (and/or lab supervisor) to determine if you should undergo LOTO Training. For example, you do NOT need LOTO Training to perform basic installations on a computer (e.g., installing more RAM, new videocard etc) but you DO need LOTO Training to install a new heating element within a furnace or perform any service on equipment that is high-voltage. To request LOTO Training, you should email Kristi Evans (REM) at klevans(a)purdue.edu, and CC mse-safety(a)purdue.edu. Please let me know if you have any questions. Thanks, Prof. Erk and the MSE Safety Committee

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