空间微重力条件下偏晶合金凝固研究进展  

Progress in the solidification of monotectic alloys under the microgravity condition of space

作　　者：江鸿翔[1] 黎旺[1] 张丽丽[1] 何杰[1] 赵九洲[1] JIANG HongXiang;LI Wang;ZHANG LiLi;HE Jie;ZHAO JiuZhou(Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]中国科学院金属研究所,沈阳110016

出　　处：《中国科学：物理学、力学、天文学》2020年第4期83-90,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:51771210,51471173,51501207);中国载人空间站项目(编号:TGJZ800-2-RW024)资助。

摘　　要：偏晶合金种类很多,若能将其制成具有理想组织结构的原位复合材料,则它们之中许多均具有优异的性能和重要的工业应用前景.然而,当均匀、单相的偏晶合金熔体冷却进入液态组元不混溶区间时会发生液-液相变,生成互不混溶的两个液相.在地面常规重力条件下冷却凝固时,熔体内往往存在较强的对流且两个液相间通常具有较大的密度差,这使得该类合金非常容易形成相偏析严重、甚至两相分层的组织.在微重力条件下冷却凝固时,由重力对流和组元间密度差引起的两相分离现象得到明显减弱,有利于该类合金凝固理论的研究和弥散型偏晶基复合材料的制备.近年来,有关微重力条件下偏晶合金凝固理论及组织控制的研究受到了材料科学领域的高度关注,人们在空间微重力条件下和地面模拟微重力条件下开展了大量的研究工作.本文综述了近年来微重力条件下偏晶合金凝固研究的进展.Monotectic alloys or alloys with a miscibility gap in the liquid state are a broad kind of materials. They are especially suitable for the manufacturing of either the in-situ particle composite materials or the composite materials with a core/shell structure and, thus, have a strong industry application background. These alloys, however, have an essential drawback that just the miscibility gap poses problems during solidification. When a single-phase melt of these alloys is cooled into the miscibility gap, it decomposes into two liquids enriched with different components. Generally, the convection flow caused by the gravity and the liquid-liquid phase transformation cause the formation of a phase segregated microstructure when these alloys are solidified under the normal gravitational conditions. Under microgravity condition, the convection flow caused by the gravity and the sediment or floating of the second phase due to the density difference between the components are obviously weakened, it is beneficial for the study of solidification theory of monotectic alloy and the preparation of monotectic alloys composited with a well dispersed microstructure. In recent decades, plenty of efforts have been made to investigate the solidification of monotectic alloys under microgravity conditions, this article will review the research work in this field during the last few decades.

关 键 词：偏晶合金 组织 微重力 凝固 

分 类 号：TG111.4[金属学及工艺—物理冶金]