超重力下的沉降过程与固态相变

Sedimentation Process and Phase Transition of Solids Under High Gravity

摘要:

介绍了超离心状态下固体中沉降过程的最新进展以及未来应用前景，主要涉及高温超速离心设备、互溶体系以及化合物材料中的超重力固态相变。近90%的固态超速离心实验是在世界第一台（熊本大学）与第二台（日本原子能研究所）高温超速离心机上，以500 ℃以下的温度与10⁶ g的最大离心加速度条件运行。强大的超重力场和温度场诱导材料中出现原子级梯度结构、晶粒生长与细化以及空位聚集等现象，并产生了新的物相结构与特性。浙江大学建造了一种实验温度高达1200 ℃的新型悬臂式高温超速离心机，为模拟高温合金在航空发动机运行环境中的合金成分、微观结构和性能演变提供了设备基础。

Abstract:

The recent progress and future prospects for ultra-centrifugal sedimentation in solids are described, mainly involving equipment, miscible systems and compounds. Almost 90% ultracentrifugation experiments were performed on the 1st and 2nd high-temperature ultracentrifuge which is typically operated at temperatures below 500 °C under the maximum centrifugal acceleration up to 10⁶ g. The strong gravitational and temperature fields induce atomic-scale graded structure, grain growth and refinement, and voids accumulation caused by the atomic sedimentation in miscible systems. New structures, properties and substances are produced in some compounds. A new cantilever high-temperature ultracentrifuge with a test temperature up to 1200 °C is under construction at Zhejiang University, making it possible to simulate the composition, microstructure and property evolution of superalloys in the operating environment of aircraft engines.