Gradient structure produced by three roll planetary milling: numerical simulation and microstructural observations

Ya Li Wang, Andrey Molotnikov, Mathilde Diez, Rimma Lapovok, Hyoun-Ee Kim, Jing Tao Wang, Yuri Estrin

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38 Citations (Scopus)


In this study a gradient grain structure was produced by processing rod billets through three roll planetary milling (also known as PSW process). This kind of gradient structure is reported to provide an excellent combination of strength and ductility owing to an ultrafinegrained surface layer and a coarsegrained interior of the billet. Specifically, copper rod samples were subjected to up to six passes of PSW at room temperature. To study the evolution of the microstructure during the deformation, microhardness measurements and Electron Backscatter Diffraction (EBSD) analysis were performed after one, three and six passes. Additionally, the distributions of the equivalent stress during PSW and the equivalent strain after processing were studied by finite element analysis using the commercial software QFORM. The results showed the efficacy of PSW as a means of imparting a gradient ultrafinegrained structure to copper rods. A good correlation between the simulated equivalent strain distribution and the measured microhardness distribution was demonstrated.
Original languageEnglish
Pages (from-to)165 - 172
Number of pages8
JournalMaterials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing
Publication statusPublished - 2015

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