In this paper we examine the effect on the determination of boundary length per unit area of the stepped nature of boundaries in orientation maps derived from electron back-scatter diffraction data.A correction factor...In this paper we examine the effect on the determination of boundary length per unit area of the stepped nature of boundaries in orientation maps derived from electron back-scatter diffraction data.A correction factor is derived for isotropic microstructures.Two measures based on length per unit area for the determination of the cross-link boundary spacing in high strain deformation microstructures are then compared.A geometric method based on subtraction of the contribution to the length per area of the lamellar boundaries gives the best results,though in some cases a method based on boundary misorientation angles may be preferred.展开更多
From the points of both molten cast iron structure and the appearing ratio of electrons in outer-layer of different atoms, analysis on enhancement mechanism of graphitization ability after processing of the iron by pu...From the points of both molten cast iron structure and the appearing ratio of electrons in outer-layer of different atoms, analysis on enhancement mechanism of graphitization ability after processing of the iron by pulse electric discharge has been made, and the theory has been proofed by corresponding experiments. The results show that when the molten cast iron is being processed by pulse electric discharge, both the size of crystal embryos that composed by Fe and C atoms as well as the number of clusters can be reduced, even be separated by such discharging; consequently results in the segre- gation of C atoms in the molten cast iron near the cathode of discharging. The nucleation of graphite in these areas of the iron has been promoted at the discharging temperature; even though such degree has not been reached, the most favorable nucleation conditions of graphite can be at least created. Under the preconditions of not breaking up the graphite crystal embryos, with proper adjustment of discharging frequency, the stronger of the electric field and the longer of the pulsation treatment time are, the more graphitization ability of the molten cast iron is. The theoretical analysis on the above rules consists well with experimental results.展开更多
基金Supported by the National Natural Science Foundation of China(No.50371041 and No.50571049)
文摘In this paper we examine the effect on the determination of boundary length per unit area of the stepped nature of boundaries in orientation maps derived from electron back-scatter diffraction data.A correction factor is derived for isotropic microstructures.Two measures based on length per unit area for the determination of the cross-link boundary spacing in high strain deformation microstructures are then compared.A geometric method based on subtraction of the contribution to the length per area of the lamellar boundaries gives the best results,though in some cases a method based on boundary misorientation angles may be preferred.
文摘From the points of both molten cast iron structure and the appearing ratio of electrons in outer-layer of different atoms, analysis on enhancement mechanism of graphitization ability after processing of the iron by pulse electric discharge has been made, and the theory has been proofed by corresponding experiments. The results show that when the molten cast iron is being processed by pulse electric discharge, both the size of crystal embryos that composed by Fe and C atoms as well as the number of clusters can be reduced, even be separated by such discharging; consequently results in the segre- gation of C atoms in the molten cast iron near the cathode of discharging. The nucleation of graphite in these areas of the iron has been promoted at the discharging temperature; even though such degree has not been reached, the most favorable nucleation conditions of graphite can be at least created. Under the preconditions of not breaking up the graphite crystal embryos, with proper adjustment of discharging frequency, the stronger of the electric field and the longer of the pulsation treatment time are, the more graphitization ability of the molten cast iron is. The theoretical analysis on the above rules consists well with experimental results.
