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SUMMARY:MEchanics GAthering -MEGA- Seminar: Precipitation strengthening of
  Al-Mg-Si alloys from mesoscale to atomistics
DTSTART:20211007T161500
DTEND:20211007T173000
DTSTAMP:20260610T121830Z
UID:ad5d4d4a658875f17ca2682a783851ef263446b9bcd7570d62723fd2
CATEGORIES:Conferences - Seminars
DESCRIPTION:Yi Hu (LAMMM\, EPFL)\nAbstract Aluminum alloys are important 
 light alloys that find a lot of applications in industry and with precipit
 ation the yield strength of the material can be improved greatly. In the c
 urrent study\, we first use mesoscale simulations\, i.e. Discrete Dislocat
 ion Dynamics (DDD)\, to study peak-aged Al–Mg–Si alloys strengthened b
 y β'' precipitates. In the process of dislocation-precipitate interaction
 \, dislocation can either shear the precipitates (Shearing mechanism) or l
 oop around them (Orowan mechanism)\, and for peak-aged material\, two mech
 anisms are thought to give the same result\, hence we only model the loopi
 ng mechanism in strength prediction. Careful simulations using experimenta
 l characterizations and proper material parameters show an overestimate of
  uniaxial tensile yield strength. And the detailed force analysis on indiv
 idual precipitates indicates that shearing happens in the strengthening pr
 ocess. To further understand the strengthening process\, we carry out atom
 istic simulations using a curated Al–Mg–Si Neural Network Potential (N
 NP)\, and the result shows that both shearing and looping can take place a
 tomistically depending on the shearing energy and precipitate internal mis
 fit stress. Theoretical shearing models and Discrete Dislocation Dynamics 
 are used for critical resolved shear stress prediction and agree well with
  the atomistic results. A yield strength prediction based on the atomistic
  knowledge and several corrections gives a much reasonable result to the s
 trength of real material.\n\nBio Yi Hu did his bachelor study in Shanghai
  at Tongji University in the field of Civil Engineering. Then he moved to 
 Stuttgart\, Germany for his master study focusing on Computational Mechani
 cs but mainly on continuum scale. At EPFL\, he works in the lab of Multisc
 ale Mechanics Modeling and has learned dislocation theory and atomistic de
 tail of crystal plasticity. He is going to finish his PhD soon in November
 .
LOCATION:MED 0 1418 https://plan.epfl.ch/?room==MED%200%201418 https://epf
 l.zoom.us/j/67873367071?pwd=b0NEeWY2MFJqNGUzUitJV256YSt6QT09
STATUS:CONFIRMED
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