摘要
采用中子衍射法测定了Ｃｒ，Ｍｏ，Ｔｉ，Ｎｉ，Ｍｎ，Ｓｉ等代位原子在ＤＯ３结构Ｆｅ３Ａｌ亚点阵中的原子占位，并从解离能角度探讨了原子对之间的相互作用及对合金室温塑性的影响、结果表明：Ｃｒ，Ｍｏ，Ｔｉ都占据Ａｌ原子的次近邻位置，替代Ｆｅ原子；Ｎｉ，Ｍｎ占据Ａｌ原子的最近邻位置；（Ｓｉ＋Ａｌ）当量成分以内的Ｓｉ原子替代占据Ａｌ原子的位置．由于Ａｌ—Ｃｒ原子对的结合能低于Ｆｅ—Ａｌ，Ａｌ—Ｍｏ及Ａｌ—Ｔｉ对，降低次近邻反相畴界能，因此。
The site occupation of substitutional atoms Cr, Mo, Ti, Ni, Mn, Si at sublattice in DO3 type stoichiometric Fe3Al intermetallics has been determined by means of neutron difractometry. On the basis of dissociation energy, the effect of atom interaction on the room temperature ductility is discussed. The experimental results indicate that Cr. Mo and Ti atoms all occupy the next nearest neighbour of Al atom, Ni and Mn atoms the nearest neighbour, while Si atom substitutes for the position of Al atom. Since the interaction energy of Al-Cr pair is lower than that of Fe-Al. Al-Mo and Al-Ti pair, the corresponding APB energy decreases and this explains why the addition of Cr improves the room temperature ductility of DO3 type Fe3Al intermetallics.
出处
《材料研究学报》
EI
CAS
CSCD
1996年第4期351-362,共12页
Chinese Journal of Materials Research
基金
国家自然科学基金
冶金工业部科技司及中国核工业总公司对本课题
关键词
中子衍射
原子占位
金属间化合物
Fe_3Al, neutron diffraction, site occupation, intermetallics, ductility
