Yan LIU
,
Zhilin LIU
,
Chengwei ZHANG
,
Yingguang ZHU
材料科学技术（英文）
By calculating the electron structures of the phases that phosphor, sulfur and alloying elements dissolving in γ-Fe, the reason why alloying elements can bring centerline segregation in continuous casting slab (CCS) with nA, the number of electrons on the strongest covalent bonds, and the structure formation factor S were investigated, and an electron structural criterion to control and to eliminate the centerline segregation was advanced. Basing on this, the electron structures of a part of rare earth phosphides and sulfides are calculated, the physical mechanism that rare earth elements can control the segregation of phosphor and sulfur is analyzed, and the criterion is well verified.
关键词:
Valence electron structure
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Fantao KONG
,
Ziyong CHEN
,
Yuyong CHEN
,
Jing TIAN
,
Yufeng SI
材料科学技术（英文）
The valence electron structure ofγ/α2 phase boundaries in lamellar colonies in Ti-47Al-2M (M=Nb, Cr, V) (at. pct) was investigated by empirical electron theory of solid and molecules (EET) and its bond-length-difference (BLD) method. On this basis, the boundary condition of electron movement was employed in the improved Thomas-Fermi-Dirac (TFD) theory to decide the continuity of the electron density of the lamellar colonies interface and it is found that ofγ/α2 interface is continuous. Furthermore, it is found that adding alloying elements (including Nb, Cr, and V) can improve the electron density ( ρ ) ofγ/α2 interface, decrease △ρ ofγ/α2 interface. With the electron structure analysis together with properties analysis, the effect mechanism of alloying elements (Nb, Cr, V) improving mechanical properties was explained.
关键词:
TiAl based alloy
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