静高压对Mn_4Si合金液－固转变中间相形成的影响及准晶相的截获

INFLUENCE OF HIGH PRESSURE ON FORMATION OF INTERMEDIATE PHASES OF Mn_4Si AND FORMATION OF DODACAGONALQUASICRYSTAL IN Mn_4Si ALLOY UNDER HIGH STATIC PRESSURE

利用静高压熔态淬火方法对Ｍｎ＿４Ｓｉ合金液－固非平衡转变过程进行了研究。发现真空熔炼的合金中常见的（Ｍｎ＿４Ｓｉ）ξ相在高压下是不稳定的。而真空熔炼合金中没有的（Ｍｎ＿６Ｓｉ）Ｒ相在高压液－固转变过程中出现了。首次在４．５ＧＰａ压力下通过熔态淬火截获到了十二次准晶相。使用透射电子衍射技术对其进行了鉴别；使用Ｘ射线衍射对各晶体相和准晶相的结构和稳定性进行了研究。

The formation and stability of the intermediate phases of Mn_4Si have been investi-gated by the method of quenching in fusing state under high static pressure(MQFSHP). The re-sults show that (Mn_4S)ξphase , which is the main part in the Mn_4Si alloy smelted in vacuumfurnace is unstable;(Mn_4Si)R phase, which is not in the Mn_4Si alloy smelted in vacuum , is ob-served by quenching from fusing state under high pressure. The dedecagonal quasicrystal hasbeen found in Mn_4Si system by MQFSHP for the first time. The structure and stability of inter-mediate phases and dedecagonal quasicrystal were analyzed by using X-ray diffraction , electrondiffraction and DTA techniques.