BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
X-WR-CALNAME:Saeed Ataollahi to Present Dissertation Research
X-WR-TIMEZONE:Eastern Time (US & Canada)
BEGIN:VEVENT
DTSTAMP:20261014T202419Z
UID:tag:localist.com\,2008:EventInstance_44127449414241
DTSTART:20230911T133000Z
DTEND:20230911T143000Z
DESCRIPTION:The UTC Graduate School is pleased to announce that Saeed Ataol
 lahi will present Doctoral research titled\, DEVELOPING A NEW INTERATOMIC 
 POTENTIAL AND ATOMISTIC STUDY OF NiTiHf on 09/11/2023 at 9:30 am in Maytag
  Room (426) or via Zoom: https://tennessee.zoom.us/j/89863653002. Everyone
  is invited to attend. \n\nComputational Science\n\nChair: Dr. Mohammad Ma
 htabi\n\nAbstract:\nWith the growing demand for high-temperature shape mem
 ory alloys (HTSMAs)\, NiTi-based HTSMAs have gained more attention for imp
 lementation in applications at elevated temperatures. Among NiTi-based all
 oys\, NiTiHf has shown to have great potential\, by having high transforma
 tion temperatures\, lower preparation cost and good thermal stability. How
 ever\, until today\, most studies conducted on NiTiHf have focused on a li
 mited range of compositions due to the difficulties and high cost of the e
 xperimental studies. Therefore\, there exists a lack of comprehensive rese
 arch on the thermo-mechanical behavior of these HTSMAs. Computational simu
 lations are a very cost-effective and feasible approach for addressing thi
 s shortcoming. Among computational methods\, molecular dynamics (MD) simul
 ation as an atomistic method offers comprehensive means to explore microst
 ructural phenomena that govern the behavior of material. An essential requ
 irement for performing MD simulations is interatomic potential which serve
 s as the constitutive equations of MD and determine the forces and interac
 tions between atoms. Since no applicable interatomic potential has been de
 veloped for NiTiHf\, there has not been any progress in MD studies on NiTi
 Hf alloys. Therefore\, in this study\, a Second Nearest-Neighbor Modified 
 Embedded Atom Method (2NN MEAM) interatomic potential has been developed t
 o accurately represent the NiTiHf ternary system. Initially\, the paramete
 rs of constituent unary and binary potentials were calibrated by fitting t
 heir reproduced results of physical properties to DFT results. Then\, the 
 final ternary MEAM potential was checked for reliability and transferabili
 ty be performing MD simulations. The results showed that the developed pot
 ential can accurately capture temperature-induced and stress-induced marte
 nsitic phase transformation in NiTiHf. In addition\, the lattice parameter
 s and formation energy of different compositions of NiTiHf were obtained a
 nd compared with experimental and DFT results showing a good agreement. Fu
 rthermore\, using the developed MEAM potential\, MD simulations were condu
 cted to analyze the influence of precipitates on the superelasticity and s
 hape memory effect of NiTiHf alloy. The results showed that in the presenc
 e of H-phase precipitates\, the transformation temperatures increase. In a
 ddition\, the thermal cycling of NiTiHf under constant stress was simulate
 d and it was found that reducing the temperature rate results in a narrowe
 r thermal hysteresis.
LOCATION:Engineering and Computer Science Building\, Maytag Conference Room
  (426)
SUMMARY:Saeed Ataollahi to Present Dissertation Research
URL;VALUE=URI:https://calendar.utc.edu/event/saeed_ataollahi_to_present_dis
 sertation_research
CATEGORIES:Lectures & Presentations
END:VEVENT
END:VCALENDAR