ISSN 2594-5327
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In this work, finite-element models and upper-bound solutions are proposed to analyze the processing of a commercial copper via equal channel angular extrusion technique (ECAE). In this way, a dislocation density constitutive formulation is adopted to account for the work-hardening and recovery phenomena which take place in this process. In relation to numerical modeling, the three-dimensional general integration procedure based upon the elastic-predictor and plastic-corrector algorithm is firstly presented within the context of the plastic flow theory along with isotropic work-hardening. Then, the implemented dislocation density model is validated for both implicit and explicit finite element integration techniques vis-à-vis to the experimental uniaxial tensile data reported in the literature for single ECAE pass of a commercial copper. Otherwise, by using the upper-bound method, the extrusion force is calculated regarding the effects of friction, tooling geometry and also material mechanical behavior with effective stress measure provided by dislocation density constitutive model. The introduction of backpressure effect showed consistent increasing of extrusion force, effective plastic strain and density dislocation in comparison with the predictions that neglected this parameter. Finally, the proposed upper-bound solutions could be validated in terms of processing load, effective plastic strain and density dislocation by equivalent obtained numerical predictions.
In this work, finite-element models and upper-bound solutions are proposed to analyze the processing of a commercial copper via equal channel angular extrusion technique (ECAE). In this way, a dislocation density constitutive formulation is adopted to account for the work-hardening and recovery phenomena which take place in this process. In relation to numerical modeling, the three-dimensional general integration procedure based upon the elastic-predictor and plastic-corrector algorithm is firstly presented within the context of the plastic flow theory along with isotropic work-hardening. Then, the implemented dislocation density model is validated for both implicit and explicit finite element integration techniques vis-à-vis to the experimental uniaxial tensile data reported in the literature for single ECAE pass of a commercial copper. Otherwise, by using the upper-bound method, the extrusion force is calculated regarding the effects of friction, tooling geometry and also material mechanical behavior with effective stress measure provided by dislocation density constitutive model. The introduction of backpressure effect showed consistent increasing of extrusion force, effective plastic strain and density dislocation in comparison with the predictions that neglected this parameter. Finally, the proposed upper-bound solutions could be validated in terms of processing load, effective plastic strain and density dislocation by equivalent obtained numerical predictions.
Palavras-chave
ECAE; Finite element; Upper-bound method; Density dislocation.
ECAE; Finite element; Upper-bound method; Density dislocation.
Como citar
Mederos, Neil de;
Moreira, Luciano Pessanha.
A DISLOCATION DENSITY-BASED ANALYSIS OF A
COMMERCIAL COPPER DEFORMED VIA ECAE
TECHNIQUE
,
p. 2120-2130.
In: 67º Congresso da ABM - Internacional / 12º ENEMET - Encontro Nacional de Estudantes de Engenharia Metalúrgica, de Materiais e de Minas,
Rio de Jabeiro,
2012.
ISSN: 2594-5327
, DOI 10.5151/2594-5327-21220
