Matter and Radiation at Extremes, Volume. 9, Issue 2, 027802(2024)

On the thermodynamics of plasticity during quasi-isentropic compression of metallic glass

Kaiguo Chen1,2、*, Bo Chen1,2, Yinan Cui3, Yuying Yu4, Jidong Yu4, Huayun Geng4, Dongdong Kang1,2, Jianhua Wu1,2, Yao Shen5, and Jiayu Dai1,2
Author Affiliations
  • 1College of Science, National University of Defense Technology, Changsha 410073, People’s Republic of China
  • 2Hunan Key Laboratory of Extreme Matter and Applications, National University of Defense Technology, Changsha 410073, People’s Republic of China
  • 3Applied Mechanics Laboratory, Department of Engineering Mechanics, School of Aerospace, Tsinghua University, Beijing 100084, People’s Republic of China
  • 4Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, People’s Republic of China
  • 5Department of Material Science and Technology, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
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    Figures & Tables(11)
    (a) Illustrations of three different compression simulations: pISE, UC-QIC, and NEMD-QIC. (b) and (c) Thermodynamic paths undergone by Cu50Zr50 metallic glass subjected to pISE, UC-QIC, and NEMD-QIC at an equivalent strain rate of ∼7.5×108/s.
    Illustration of the reference isentrope, instant isentrope, and quasi-isentrope without phase transition. States A and C have the same density, and states B, D, and E have the same density.
    Illustration of the framework integrating thermodynamics, mechanics, and microstructural analysis.
    (a) Shear modulus mapped into pressure and density. (b) Grüneisen parameter vs density at 300, 400, 500, and 600 K. (c) Vibrational entropy mapped into pressure and density. (d) Isochoric heat capacity vs nonaffine atomic strain at different densities and temperatures.
    (a) Isentrope recovered from P–ρ–T path. (b) Excess temperature increase ΔTexcess vs density. (c) Strength vs density during pISE, UC-QIC, and NEMD-QIC with an equivalent strain rate of ∼7.5×108/s. The light red box represents the elastic deformation regime for NEMD-QIC and roughly for UC-QIC. Gray dots indicate where ΔTexcess starts to increase.
    (a) Excess temperature ΔTexcess at ρ/ρ0 = 1.29 and scaled strength vs rise time trise. A separation between rate-insensitive and rate-sensitive regime is revealed. (b) Taylor–Quiney factor βint vs plastic strain during NEMD-QIC. (c) Replica distance and fraction of extra cage breakage at yielding vs trise. The separation between rate-insensitive and rate-sensitive regime is the same as in (a). (d) A cross-section colored by dX,Yi in a yield replica of the case trise = 67 ps.
    (a) Total entropy increase ΔStot, configurational entropy increase ΔSconf, and vibrational entropy increase ΔSvib vs relative density during NEMD-QIC. (b) Entropy increases at ρ/ρ0 = 1.29 vs rise time. The entropy increases for shock compression (trise = 0 ps) are also shown.
    (a) Local fivefold symmetry (LFFS) vs relative density under compression. (b) Shannon entropy defined on a copper-centered polyhedron distribution vs relative density. Only compressions in the rate-insensitive regime are shown.
    (a) Configurational entropy vs Shannon entropy defined on copper-centered polyhedron distribution. (b) Taylor–Quinney factor (TQF) vs configurational entropy change during plastic regime for NEMD-QIC. Only compressions in the rate-insensitive regime are shown. Black solid lines are fitting curves.
    (a) Configurational energy vs plastic strain. (b) Effective temperature and temperature vs plastic strain. Only compressions in the rate-insensitive regime are shown.
    • Table 1. Fitting parameters of thermophysical properties of the model Cu50Zr50. The equation is H(ρ,T,γa)=h0[1+h1ρ/ρ0+h2(ρ/ρ0)2](1+h3T+h4T2)(1+h5γa+h6γa2), in which ρ is in units of kg/m3, T is in units of K, and γa is dimensionless. CV is the isochoric heat capacity, γg the Grüneisen parameter, B the bulk modulus, G the shear modulus, Svib the vibrational entropy, and F the Helmholtz free energy containing only a vibrational contribution.

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      Table 1. Fitting parameters of thermophysical properties of the model Cu50Zr50. The equation is H(ρ,T,γa)=h0[1+h1ρ/ρ0+h2(ρ/ρ0)2](1+h3T+h4T2)(1+h5γa+h6γa2), in which ρ is in units of kg/m3, T is in units of K, and γa is dimensionless. CV is the isochoric heat capacity, γg the Grüneisen parameter, B the bulk modulus, G the shear modulus, Svib the vibrational entropy, and F the Helmholtz free energy containing only a vibrational contribution.

      h0h1h2h3h4h5h6
      CV (J mol−1 K−1)28.60.252−0.140−9.44 × 10−44.67 × 10−7−0.1450.847
      γg1.1664.266−3.500−7.087 × 10−42.38 × 10−7−1.0144.623
      B (GPa)300.0−1.7961.2811.029 × 10−4−1.35 × 10−7−0.1295.77 × 10−2
      G (GPa)10.41.47 × 10−32.0458.264 × 10−44.84 × 10−7−1.635.56
      Svib (kB/atom)3.88−5.270.00173.286.24 × 10−8−0.0110.168
      F (eV/atom)−0.2472.398−1.348−2.353 × 10−58.14 × 10−8−5.18 × 10−30.0352
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    Kaiguo Chen, Bo Chen, Yinan Cui, Yuying Yu, Jidong Yu, Huayun Geng, Dongdong Kang, Jianhua Wu, Yao Shen, Jiayu Dai. On the thermodynamics of plasticity during quasi-isentropic compression of metallic glass[J]. Matter and Radiation at Extremes, 2024, 9(2): 027802

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    Paper Information

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    Received: Sep. 11, 2023

    Accepted: Jan. 10, 2024

    Published Online: Apr. 15, 2024

    The Author Email: Chen Kaiguo (chenkaiguo@nudt.edu.cn)

    DOI:10.1063/5.0176138

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