Three-dimensional study of nodule clustering and heterogeneous strain localization for tailored material properties in ductile iron

Joint 5th International Conference on Advances in Solidification Processes;5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining

土木建筑工程;计算机科学

Olofsson, Jakob^1 ; Salomonsson, Kent^1 ; Dahle, Arne K.^1 ; Mathiesen, Ragnvald H.^2

Department of Materials and Manufacturing, School of Engineering, Jönköping University, Box 1026, Jönköping

SE-551 11, Sweden^1

Department of Physics, Faculty of Natural Sciences, Norwegian University of Science and Technology, NTNU, Trondheim

NO-7491, Norway^2

关键词: Heterogeneous distributions;    Heterogeneous strain;    Material performance;    Microstructural features;    Optimized geometries;    Physiological structures;    Solidification condition;    Three-dimensional reconstruction;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/529/1/012078/pdf
DOI  :  10.1088/1757-899X/529/1/012078

来源: IOP

【 摘 要 】

Tailored heterogeneous distributions of microstructural features enable extraordinary material performance in biological and physiological structures such as trees, the aortic arch, human teeth and dinosaur skulls. In ductile iron, a heterogeneous distribution in size and morphology of graphite nodules and variations of the fractions of ferrite and pearlite are created during solidification, and varies as a function of parameters such as local cooling rate, segregation and flow. In the current work, the size distribution as well as the orientation and relation between graphite nodules is obtained by a three-dimensional reconstruction of a ductile iron microstructure from X-ray tomography. The effect of the nodule morphology and clustering on the localization of plastic strains is studied numerically using finite element analysis of the reconstructed microstructure. Real castings have a variation in geometry, solidification conditions and are subjected to variations in loads. A framework for optimized geometry and solidification conditions in order to design and deliver castings with tailored local material performance is proposed.