Fe-Cu two-phase nanocomposites: application of a modified rule of mixtures

2019-11-09 02:57:15

phase Cu Fe grain boundaries

责任者: He, L.;Allard, L.F.;Ma, E. 单位: Dept. of Mech. Eng., Louisiana State Univ., Baton Rouge, LA, USA 来源出处: Scripta Materialia(Scr. Mater. (USA)),2000/02/14,42(5):517-23 摘要: Full-density Fe-Cu two-phase nanocomposites show microhardness considerably higher than the ROM averages of constituent metals with the same nanophase grain size. This observation indicates that other than grain sizes and nominal phase volume fractions (used in ROM), microstructural arrangements of the two phases and phase boundary strengthening are additional factors that need to be considered. These factors are particularly important for nanocomposites because of the unusually high fraction of interphase boundaries (Fs) compared with grain boundaries due to the ultrafine phase domain sizes. We constructed a modified rule of mixtures which, although obviously simplistic, provides an approximate picture and a useful perspective for understanding how a nanocomposite would behave. In Fe/Cu, BCC/FCC interphase boundaries appear to be more effective barriers to the transmission of deformation than grain boundaries in elemental Cu and Fe 关键词: composite material interfaces;copper alloys;field emission electron microscopy;grain boundaries;grain size;iron alloys;mechanical alloying;microhardness;mixing;nanostructured materials;phase equilibrium;powder metallurgy;solid solubility;transmission electron microscopy;full-density Fe-Cu two-phase nanocomposites;microhardness;nanophase grain size;nominal phase volume fractions;microstructural arrangements;phase boundary strengthening;body centred cubic/face centred cubic interphase boundaries;ultrafine phase domain sizes;modified rule of mixtures;grain boundaries;Fe-Cu