Simulation of Microstructure Evolution during Shape Rolling with the Use of Frontal Cellular Automata

Abstract

The objective of the paper is an application of the model of the microstructure evolution based on three-dimensional cellular automata (CA) for hot shape rolling simulation. A short description of frontal cellular automata (FCA) is presented. The model contains two parts: the deformation and the microstructure evolution. The CA cells do not remain as undistorted cubes, but they are deformed according to the strain tensor. The independence of the grain growing from the shape and the sizes of the cell is ensured by the so-called "virtual front tracking". The microstructural part of the model simulates two phenomena: the nucleation and the growth of nuclei. There are three issues considered in the paper: the creation of the initial microstructure, the recrystallization and the phase transformation. When recrystallization is simulated, the nucleation and the grain boundary migration depend on the deformation parameters such as: the temperature, the strain, the strain rate, the dislocation density and the crystallographic orientation. The nucleation during the phase transformation is a function of the cooling rate and the final microstructure. These phenomena along with the deformation can be modeled over a wide range of multi-stage deformation processes. The process of shape rolling is chosen as an example. The data needed for the FCA calculations is received from the modeling by the finite element method. The results of the simulation of the microstructure evolution, during the last three passes of the round bars rolling with the consequent phase transformation, are presented in the paper.

Powder bed generation in integrated modelling of additive layer manufacturing of orthopaedic implants

“…The methodology is already used for modelling of solidification, dynamic and static recrystallisation [47], crack propagation, grain refinement and phase transformation [48,49]. This new CA-based model of powder bed generation provides an effective method of generating desirable digital particle Fig.…”

Flow stress models for deformation under varying condition—finite element method simulation

“…Model proposed by Sellars [18] or cellular automata [19][20][21][22] could be used for calculation of the fraction of recrystallization χ. But it is calculated in the way proposed by Svyetlichnyy [14].…”

Modeling with FCA-Based Model of Microstructure Evolution of MgCa08 Alloy During Drawing of Thin Wire in Heated Die / Modelowanie Za Pomocą FCA Rozwoju Mikrostruktury Stopu MgCa08 Podczas Ciągnienia Cienkiego Drutu W Podgrzewanym Ciagadle

“…Description of some modules of the system can be found in previous publication: initial microstructure [31], crystallization [14], recrystallization [19,21], phase transformation [23] and grain refinement [27]. Results of modelling and simulation with this FCA-based system are presented elsewhere: solidification in continuous casting [14], hot flat and shape rolling [21,30], the roll-bonding process and MAXStrain technology [27,32], powder bed generation [33], etc.…”

“…The database of materials completes the system. FCA and their computational advantages are described in detail elsewhere [19,21,23,27]. Consideration of the deformation in FCA is described as well [21,30].…”

“…The CA applications for simulations of different phenomena are very important in the materials science, and their role is increasing. CA are used for modelling of crystallization (solidification) [9][10][11][12][13][14], dynamic and static recrystallization [15][16][17][18][19], phase transformation [17,[20][21][22][23], cracks propagation, grain refinement [24][25][26], etc. Complex microstructural phenomena and technological processes are modelled on the base of CA.…”