DEVELOPMENT OF MICROSTRUCTURE-AND MECHANISM-BASED MODELING TOOLS FOR PLASTIC DEFORMATION IN MULTIPHASE ALLOYS
(0) The key to predicting,and therefore optimizing,properties of materials is the knowledge of the state of microstructure and its evolution.Recent investigations of creep deformation of Ni-base superalloys and alpha/beta Ti-alloys 1 demonstrate clearly the importance of detailed microstructural features in determining dislocation-precipitate interactions and the corresponding kinetic pathways of the deformation process.Many new dislocation processes beyond the conventional bypass and cutting mechanisms have been observed.Obviously without capturing the spatial variation,correlation and anisotropy of the multiphase microstructttres and the intimate coupling between precipitate microstructure and dislocation activities,any modeling attempt to describe the microstructure-property relationship will remain phenomenological and of limited predictive power. In this presentation we show the synergy of coupling experimental characterization to multi-scale computer simulations in developing fundamental understanding of micromechanisms that govern plastic deformation in multiphase materials,which is critical in formulating microstructure-and mechanism-based modeling tools to assist in alloy design and optimization.In particular we demonstrate the unique opportunities offered by the microscopic phase field (MPF) model to treat complex dislocation-microstructure interactions in multi-phase alloys without any a priori assumptions about dislocation geometry,core srtucture,and formation of various stacking faults.In combination with ab initio calculations of generalized stacking fault energy and the nudged elastic band method,we show the ability of MPF in quantitative characterization of the minimum energy paths and activation energies of various dislocation -precipitate interactions processes.
N.Zhou C.Shen J.Li M.J.Mills Y.Wang
Department of Materials Science and Engineering,The Ohio State University,2041 College Road,Columbus GE Global Research,1 Research Circle,Niskayuna,New York 12309,USA Department of Materials Science and Engineering,University of Pennsylvania,3231Walnut Street,Philade
国际会议
第二届国际非均质材料力学会议(The Second International Conference on Heterogeneous Material Mechanics)
安徽黄山
英文
432
2008-06-03（万方平台首次上网日期，不代表论文的发表时间）