Modeling peak-aged precipitate strengthening in Al-Mg-Si alloys


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{
  "metadata": {
    "is_last": true, 
    "publication_date": "Jan 21, 2022, 17:10:08", 
    "edited_by": 576, 
    "version": 1, 
    "license": "Creative Commons Attribution 4.0 International", 
    "license_addendum": null, 
    "_files": [
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        "size": 88208, 
        "description": "precipitate positions and dimensions for each pseudo-random microsture"
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        "description": "the set of simulation results using finite temperature dislocation core energy"
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    ], 
    "mcid": "2022.10", 
    "keywords": [
      "Aluminum", 
      "Metallurgy", 
      "Discrete Dislocation Dynamics", 
      "Precipitation strengthening", 
      "Orowan Mechanism", 
      "MARVEL/DD2"
    ], 
    "contributors": [
      {
        "givennames": "Yi", 
        "email": "yi.hu@epfl.ch", 
        "familyname": "Hu", 
        "affiliations": [
          "LAMMM Laboratory for Multiscale Mechanics Modeling, \u00c9cole Polytechnique F\u00e9d\u00e9rale de Lausanne, CH-1015, Vaud, Switzerland"
        ]
      }, 
      {
        "givennames": "William", 
        "email": "william.curtin@epfl.ch", 
        "familyname": "Curtin", 
        "affiliations": [
          "LAMMM Laboratory for Multiscale Mechanics Modeling, \u00c9cole Polytechnique F\u00e9d\u00e9rale de Lausanne, CH-1015, Vaud, Switzerland"
        ]
      }
    ], 
    "status": "published", 
    "doi": "10.24435/materialscloud:2c-7c", 
    "title": "Modeling peak-aged precipitate strengthening in Al-Mg-Si alloys", 
    "id": "1200", 
    "description": "Strengthening by needle-shaped \u03b2\u2032\u2032 precipitates is critical in Al\u2013Mg\u2013Si alloys. Here, the strengthening is studied computationally at the peak-aged condition where precipitate shearing and Orowan looping are usually considered to have equal strengths. Pseudo-random precipitate microstructures are constructed based on experimental precipitate dimensions and volume fractions at peak aging. A Discrete Dislocation Dynamics method is then adapted to compute the Critical Resolved Shear Stress (CRSS) for Orowan looping of dislocations moving through the non-shearable precipitate field. The CRSS for Orowan looping is determined by a typical in-situ precipitate spacing that is smaller than the average spacing and by the dislocation core energy within a radius of \u22485b, a factor rarely considered. The matrix misfit stresses, volume fraction, and precipitate shape have small effects on the CRSS. With microstructure and property details introduced as faithfully as possible, the CRSS for Orowan looping using atomistically-calibrated core energies at room temperature is nonetheless \u224833% higher than experiments. This suggests that precipitate shearing controls strength, and analyses of (i) forces acting on the precipitates, (ii) misfit stresses inside the precipitates, (iii) first-principles results for the relevant precipitate fault energies, and (iv) simulations that mimic precipitate shearing indicate a shearing CRSS closer to experiments. Thus, Orowan looping only sets an upper bound for the CRSS even at peak aging, and further quantitative progress requires detailed modeling of precipitate shearing.", 
    "owner": 636, 
    "_oai": {
      "id": "oai:materialscloud.org:1200"
    }, 
    "conceptrecid": "1199", 
    "references": [
      {
        "doi": "10.1016/j.jmps.2021.104378", 
        "url": "https://www.sciencedirect.com/science/article/pii/S002250962100065X?via%3Dihub", 
        "citation": "Hu, Yi, and W. A. Curtin, Journal of the Mechanics and Physics of Solids 151 (June 1, 2021): 104378.", 
        "type": "Journal reference"
      }
    ]
  }, 
  "updated": "2022-01-21T16:10:08.431705+00:00", 
  "revision": 10, 
  "id": "1200", 
  "created": "2022-01-04T16:17:31.393131+00:00"
}