scholarly journals Prediction of Transient Hardening after Strain Path Change by a Multi-scale Crystal Plasticity Model with Anisotropic Grain Substructure

2014 ◽  
Vol 81 ◽  
pp. 1318-1323 ◽  
Author(s):  
Philip Eyckens ◽  
Albert Van Bael ◽  
Jaap Moerman ◽  
Henk Vegter ◽  
Paul Van Houtte
2014 ◽  
Vol 783-786 ◽  
pp. 2567-2572
Author(s):  
Mattias Gärdsback ◽  
Guo Cai Chai ◽  
David Hedström ◽  
Katarina Persson

The effect of strain path on work hardening and texture for a super austenitic stainless steel was investigated using both experiments and modeling. Compression deformation tests by stepwise changing loading direction in two and three dimensions were performed on cubic specimens at room temperature. The results were compared to uniaxial compression with equal accumulative strain, up to 20%, and uniaxial tension with equal final strain, up to 10% elongation of the longest side. The textures in all samples were analyzed using pole figures from EBSD analysis. Because of the high stacking fault energy of this super austenitic stainless steel, the texture was dominated by <110>-fiber texture in the compressive direction for the uniaxial compression, <111>- and <100>-fiber texture in the tensile direction for the uniaxial tensile test, and a combination of all these for the cube deformation. The density of the texture was much weaker for samples where the loading direction altered, if samples with equal accumulated strain were compared. The cube deformation was also modeled using a crystal plasticity model. The crystal plasticity model consists of a representative volume element (RVE) containing crystal grains with random orientations. The Taylor assumption was used for homogenization between the macro-and subscale. The material parameters in the crystal plasticity model were determined by calibration of its macroscopic response to experimental data. The simulated textures correspond rather well to the experimental results, but the work hardening should be completed to take into account kinematic hardening.


2008 ◽  
Vol 24 (8) ◽  
pp. 1360-1379 ◽  
Author(s):  
Bjørn Holmedal ◽  
Paul Van Houtte ◽  
Yuguo An

2012 ◽  
Vol 201-202 ◽  
pp. 1110-1116
Author(s):  
Mei Yang ◽  
Xiao Yan Zhang ◽  
Hao Wang

In this paper, the forming limit of a body-centered cubic (BCC) sheet metal under non-proportional strain-path is investigated by using the Marciniak and Kuczynski approach integrated with a rate-dependent crystal plasticity model. The prediction model has been proved to be effective in predicting Forming Limit Diagram (FLD) of anisotropic sheet metal with FCC type of slip systems[1]. The same model has been used to study the FLD under non-proportional strain-path of BCC slip systems numerically and experimentally. The agreement between the experiments and simulations is good. With crystal plasticity model well describing the crystal microstructure effect, our model can be used to predict the FLD of BCC sheet metal under complicated strain path in plastic forming process with good accuracy.


Author(s):  
MK Samal

Development of reliable computational models to predict the high temperature deformation behavior of nickel-based superalloys is in the forefront of materials research. These alloys find wide applications in manufacturing of turbine blades and discs of aircraft engines. The microstructure of these alloys consists of the primary γ′-phase, and the secondary and tertiary precipitates (of Ni3Al type) are dispersed as γ′-phases in the gamma matrix. It is computationally expensive to incorporate the explicit finite element model of the γ-γ′ microstructure in a crystal plasticity-based constitutive framework to simulate the response of the polycrystalline microstructure. Existing models in literature do not account for these underlying micro-structural features which are important for simulation of polycrystalline response. The aim of this work is to develop a physically motivated multi-scale approach for simulation of high temperature response of nickel-based superalloys. At the lower length scale, a dislocation density-based crystal plasticity model is developed which simulates the response of various types of microstructures. The microstructures are designed with various shapes and volume fractions of γ′-precipitates. A new model for simulation of the mechanism of anti-phase boundary shearing of the γ′-precipitates, by the matrix dislocations, is developed in this work. The lower scale model is homogenized as a function of various micro-structural parameters, and the homogenized model is used in the next scale of multi-scale simulation. In addition, a new criterion for initiation of micro-twin and a constitutive model for twin strain accumulation are developed. This new micro-twin model along with the homogenized crystal plasticity model has been used to simulate the creep response of a single crystal nickel-based superalloy, and the results have been compared with those of experiment from literature. It was observed that the new model has been able to model the tension–compression asymmetry as observed in single crystal experiments.


2021 ◽  
Author(s):  
Artyom A. Tokarev ◽  
Anton Yu. Yants ◽  
Alexey I. Shveykin ◽  
Nikita S. Kondratiev

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