Controlled mechanical response in glasses via designed spatial inhomogeneity

Statphys Meeting ICTS; February 1-3, 2023
https://www.icts.res.in/discussion-meeting/ispcm
Associated video link from YouTube: https://youtu.be/aiObCrUpLK4?si=fl7J5WK3wS5WDHDh

Also another version of the talk delivered at IMSc: Frontiers in Non-equilibrium Physics (17-20/01/2023)
Associated video link from YouTube: https://youtu.be/_Plj4nvjfBA?si=6MGU6ML_SOvS0_Ma

Related publication:
https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.7.095601

Transcript

1. Controlled mechanical response in glasses via designed spatial inhomogeneity VINAY VAIBHAV The Institute of Mathematical Sciences, Chennai University of Milan, Italy Statphys Meeting ICTS February 1-3, 2023 Pinaki Chaudhuri, IMSc Chennai Jürgen Horbach, HHU Düsseldorf
2. Deformed amorphous solids: inhomogeneous patterns Computer Simulations Experiments J. J. Lewandowski et al. Nat. Mat. 5, 15 (2006) Metallic glass Y. Cao et al. Nat. Comm. 9, 2911 (2018) Granular material V. Chikkadi et al. PRL 107, 198303 (2011) Colloidal glass MD simulation: LJ system DEM simulation: granular powder MD simulation: soft repulsive suspension M. Ozawa et al. PNAS 115, 26 (2018) A. Singh et al. PRE 90, 22202 (2014) V. Vasisht et al. PRE 102, 12603 (2020)
3. Deformed amorphous solids: inhomogeneous patterns Computer Simulations Experiments J. J. Lewandowski et al. Nat. Mat. 5, 15 (2006) Metallic glass Y. Cao et al. Nat. Comm. 9, 2911 (2018) Granular material V. Chikkadi et al. PRL 107, 198303 (2011) Colloidal glass MD simulation: LJ system DEM simulation: granular powder MD simulation: soft repulsive suspension M. Ozawa et al. PNAS 115, 26 (2018) A. Singh et al. PRE 90, 22202 (2014) V. Vasisht et al. PRE 102, 12603 (2020) Shear band nucleation is stochastic? How to control the nucleation and growth?
4. Controlling the shear band nucleation and growth Ozawa, Berthier, Biroli, and Tarjus, PRR, 4, 23227602 (2022) Deformation of Porous glass Control over: yield strength, elastic modulus, direction band propagation Early nucleation; near voids Synthetic soft region in well-annealed glass Shear band nucleation in soft regions
5. Designing Spatially Inhomogeneous Glasses T = 0.2 TCOLD = 0.2 THOT = 0.5 T = 0.2 Before switching on the gradient During gradient is on After switching off the gradient THOT = 0.5 Inhomogeneous structures are stable over a longer period of time V. Vaibhav, J. Horbach and P. Chaudhuri; Phys. Rev. E 101, 022605 (2020) MD simulation of model binary LJ glass-former: TMCT ~ 0.435, Tg ~ 0.3 Apply a temperature gradient pulse
6. Designing Spatially Inhomogeneous Glasses T = 0.2 TCOLD = 0.2 THOT = 0.5 T = 0.2 Before switching on the gradient During gradient is on After switching off the gradient THOT = 0.5 Inhomogeneous structures are stable over a longer period of time V. Vaibhav, J. Horbach and P. Chaudhuri; Phys. Rev. E 101, 022605 (2020) MD simulation of model binary LJ glass-former: TMCT ~ 0.435, Tg ~ 0.3 Apply a temperature gradient pulse https://www.trumpf.com/en_US/applications/laser-welding/ Laser welding
7. Profiles after switching off the gradient # Order of heterogeneity depends on — size of thermal gradient — exposure time of thermal gradient # Nature of heterogeneity depends on TH — Rejuvenation vs melting Designing Spatially Inhomogeneous Glasses Density Potential energy 0.95 1.00 1.05 ˜ r(z) (a) 10 30 50 70 90 z °6.7 °6.5 °6.3 U(z) (b) No gradient TH = 0.30 TH = 0.40 TH = 0.50 TC = 0.2 Varying gradient strength, fixed exposure time TMCT ~ 0.435, Tg ~ 0.3
8. Profiles after switching off the gradient # Order of heterogeneity depends on — size of thermal gradient — exposure time of thermal gradient # Nature of heterogeneity depends on TH — Rejuvenation vs melting Designing Spatially Inhomogeneous Glasses Density Potential energy 0.95 1.00 1.05 ˜ r(z) (a) 10 30 50 70 90 z °6.7 °6.5 °6.3 U(z) (b) No gradient TH = 0.30 TH = 0.40 TH = 0.50 TC = 0.2 Varying gradient strength, fixed exposure time TMCT ~ 0.435, Tg ~ 0.3 Spatially inhomogeneous glass at T = 0.2 Goal: pathway to mechanical failure
9. Shear response of thermally processed states # Deforming the heterogeneous samples at fixed shear-rates # XZ-plane is sheared along X-direction # T = 0.2 maintained using DPD thermostat Z X Y Spatial inhomogeneity along Z-direction Shear direction Z 20 X 20 X 100 X
10. 0.0 0.5 1.0 1.5 0.2 0.6 1.0 sxz (a) 0 6 12 18 g °6.54 °6.50 °6.46 hUi (b) No gradient TH = 0.30 TH = 0.40 TH = 0.50 0.0 0.1 0.2 0.5 1.0 # Modified yielding response #Timescale for emergence of non-equilibrium steady-state depends on history Deforming the heterogeneous samples at fixed shear-rates at fixed temperature (T = 0.2) Shear-rate = 10-3 Stress vs strain Potential energy vs strain TC = 0.2 TH = 0.30, 0.40, 0.50 Shear response of thermally processed states
11. # Shear band: region of high mobility # Mobility: squared displacement of particle # Control over the formation of shear-bands? Tc = 0.2, Th = 0.50 Tc = 0.2, Th = 0.40 No gradient 0.1 0.5 1.0 2.0 5.0 Strain 1.0 0.0 Mobility Local mobility (strain = 0.1) vs fluctuation in local potential energy (strain = 0) 0.0 0.1 0.2 0.3 Mobility °0.2 °0.1 0.0 0.1 0.2 DU 0.0 0.1 0.2 0.3 Mobility °0.2 °0.1 0.0 0.1 0.2 DU No gradient TC = 0.2 TH = 0.3 TC = 0.2 TH = 0.4 TC = 0.2 TH = 0.5 Deforming the heterogeneous samples at fixed shear-rates 10-4 Shear bands in heterogenous samples: position of nucleation
12. Unprocessed sample T = 0.2 Processed sample Tc = 0.2 and TH = 0.5 Shear bands in heterogenous samples
13. # Deforming the heterogeneous samples at fixed shear-rate 10-4 # Temperature control using DPD thermostat # Checking stochasticity: — same initial undeformed sample — change the DPD seed # Shear band nucleation is not stochastic if there is sufficient inhomogeneity Shear bands in heterogenous samples: stochastic or deterministic? TC = 0.2, TH = 0.5 TC = 0.2, TH = 0.4 TC = 0.2, TH = 0.3 No gradient 4.0 0.1 0.5 1.0 2.0 5.0 0.0 1.0 Mobility: (a) (b) (c) (d) Strain 10 samples with same initial configuration but different noise of thermostat
14. Designing Spatially Inhomogeneous Glasses 0.26 0.28 0.30 U(z) 10 30 50 70 z 0.97 1.00 1.03 r(z) Well annealed w = 40 w = 20 w = 10 Poorly annealed PA Mobility: 0.0 1.0 WA w = 10 w = 20 w = 40 1.0 0.0 Mobility PA w= 20 w= 10 w= 40 WA Protocol 2: spatially inhomogeneous annealing — Hybrid swap Monte-Carlo and MD — swap MC is applied only in central region of width w # Inhomogeneity is dominated by potential energy # Inhomogeneous structures are stable for a long time # Shear band nucleates in the high energy regions; lifetime is longer For hybrid swap MC-MD: V. Vaibhav, J. Horbach and P. Chaudhuri; JCP 156, 244501 (2022)
15. 0.95 1.00 1.05 ˜ r(z) (a) 10 30 50 70 90 z °6.7 °6.5 °6.3 U(z) (b) No gradient TH = 0.30 TH = 0.40 TH = 0.50 Tuning the spatial inhomogeneity in glasses — Temperature gradient pulse — Inhomogeneous annealing Summary Controlled mechanical failure in glasses via designed spatial inhomogeneity V. Vaibhav, J. Horbach and P. Chaudhuri; submitted (2023) Response of glassy liquids to thermal gradients V. Vaibhav, J. Horbach and P. Chaudhuri; Phys. Rev. E 101, 022605 (2020) 0.26 0.28 0.30 U(z) 10 30 50 70 z 0.97 1.00 1.03 r(z) Well annealed w = 40 w = 20 w = 10 Poorly annealed THot TCold Controlled pathway to failure
16. 0.95 1.00 1.05 ˜ r(z) (a) 10 30 50 70 90 z °6.7 °6.5 °6.3 U(z) (b) No gradient TH = 0.30 TH = 0.40 TH = 0.50 Tuning the spatial inhomogeneity in glasses — Temperature gradient pulse — Inhomogeneous annealing Summary Controlled mechanical failure in glasses via designed spatial inhomogeneity V. Vaibhav, J. Horbach and P. Chaudhuri; submitted (2023) Response of glassy liquids to thermal gradients V. Vaibhav, J. Horbach and P. Chaudhuri; Phys. Rev. E 101, 022605 (2020) 0.26 0.28 0.30 U(z) 10 30 50 70 z 0.97 1.00 1.03 r(z) Well annealed w = 40 w = 20 w = 10 Poorly annealed THot TCold Controlled pathway to failure Thank you