A dislocation density-based meshfree computational framework for solid phase processing

• Published in: International journal of mechanical sciences Vol. 267; no. C; p. 108962
• Main Authors: Li, Lei, Escobar, Julian D., Das, Hrishikesh, Shukla, Shivakant, Schuessler, Benjamin J., Overman, Nicole R., Grant, Glenn J., Mathaudhu, Suveen N., Dos Santos, Jorge F., Powell, Cynthia A., Soulami, Ayoub
• Format: Journal Article
• Language: English
• Published: United Kingdom Elsevier Ltd 01.04.2024; Elsevier
• Subjects: Dislocation density; Friction extrusion; Friction stir processing; Process modeling; Smoothed particle hydrodynamics; Stick-slip contact condition; Dislocation density; Smoothed particle hydrodynamics; Stick-slip contact condition; Process modeling; Friction stir processing; Friction extrusion
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/j.ijmecsci.2024.108962

•A dislocation density-based meshfree model is proposed for solid phase processing.•Friction stir processing and extrusion are modeled and validated by experiments.•Model helps reveal unique contact and heat generation features in both processes.•The predicted high-dislocation regions agree with observed grain refinement zones. This work proposes a computational modeling framework capable of predicting the behavior of materials when subject to solid phase processing (SPP). A macroscopic dislocation density based constitutive model with internal state variables correlated to microscopic dislocation densities is incorporated into a meshfree smoothed particle hydrodynamics (SPH) framework able to handle large deformations and high temperatures typical of what a material undergoes during SPP. Unlike phenomenological constitutive models that typically neglect material microstructural contributions to macroscale response, the dislocation density based constitutive model improves significantly the predictivity of our modeling framework in a wider range of conditions and allows the multiscale material responses to be simulated simultaneously. With dislocation density based model parameters calibrated to AA1100-O aluminum test data, the generality of the proposed framework is tested on two SPP techniques, namely friction extrusion (FE) and friction stir processing (FSP). Simulation results with different process parameters are systematically validated by experimental data for both cases. The validated models are then used to elucidate the inherent physics associated with SPP by revealing the distributions of temperature, strain, strain rate, and dislocation density, stick-slip contact conditions, and heat generation rates. Model-predicted high dislocation density regions in the processed AA1100-O also agree well with the dynamically recrystallized grain refinement zones observed from experiments. [Display omitted]