TY - EJOU AU - Nakagaki, Michihiko AU - Takashima, Shuji AU - Matsumoto, Ryosuke AU - Miyazaki, Noriyuki TI - An Aspect of Hall-Petch Effect in Metallograin Structure T2 - Computer Modeling in Engineering \& Sciences PY - 2005 VL - 10 IS - 3 SN - 1526-1506 AB - The present paper focuses on the micromechanical phenomena occurring in the polycrystalline metal materials. Correlations between the material hardening and the plastic lattice dislocation were discussed with the presence of the grain boundary. The characteristic distribution of the plastic strain gradient is numerically recognized, and hence the validity of incorporating the strain gradient term in the constitutive law is demonstrated. Also, the modeling of the inclusion interface sliding and debonding was performed on the equivalent inclusion theory to develop the constitutive law for the composite. The sliding model is considered to be effective to model the superplastic behavior of highly ductile metals. The superplastic phenomenon was recognized in the numerical test with the use of the presently suggested particle dispersed model, and its mechanism was attempted to be explained. KW - Polycrystal KW - Hall-Petch effect KW - Strain gradient KW - Size effect KW - Super plasticity KW - Grain sliding KW - Equivalent inclusion model KW - Self-consistency DO - 10.3970/cmes.2005.010.199