材料期刊网

铪元素对铸造铝合金晶粒细化的机制

李红英 , 李德望 , 祝志祥 , 陈保安 , 陈新 , 杨长龙 , 张宏宇 , 康巍

中国有色金属学报(英文版) doi:10.1016/S1003-6326(16)64438-2

通过金相显微镜观察、电子显微观察和 X 射线衍射分析研究了铪元素的加入对铸造铝合金晶粒细化的影响。研究结果表明，铪元素的加入可以有效地细化合金晶粒，在凝固过程中铪元素可与铝反应形成 Al3Hf 粒子，初生的 Al3Hf 粒子可以作为基体有效的形核质点，与基体共格、纳米级别的 Al3Hf 粒子可以通过钉扎效应抑制晶粒的长大。由溶质原子理论和晶体学研究确定了实验合金的晶粒细化机制，具有两种不同的类型：低铪含量的细化效应主要是由 Hf 原子引发的成分过冷所致，中铪和高铪含量的细化效应为溶质原子与 Al3Hf 粒子共同作用所致。

关键词: 晶粒细化机制 , 铝合金 , 铸造 , 铪 , Al3Hf

Hafnium in Aluminum Alloys: A Review

Zhi-Hong Jia , Hui-Lan Huang , Xue-Li Wang , Yuan Xing , Qing Liu

金属学报(英文版) doi:10.1007/s40195-016-0379-0

Lots of the available literatures on hafnium in aluminum alloys are reviewed. The new binary Al-Hf phase diagram is simply assessed. Two ternary phase diagrams including Al-Hf-Zr and Al-Hf-Sc are accounted for, with emphasis on the aluminum rich part of the diagrams. The relationship between different structure Al₃Hf and several different formation mechanisms including the probable phase transformation mechanisms is described. The continuous Al₃Hf phase particles can serve as a grain refiner in the Al melt and a precipitate for controlling the grain structure of the alloy and a strengthening precipitate. A series of effects of Fe, Si, Zr, Sc and Li addition on the behavior of Al₃Hf and Al alloys are given. Moreover, the effects of Hf on the microstructure and properties of Al alloys, such as hardness and creep, are reviewed. Finally, some views of Hf-containing Al alloys are summarized.

关键词:

Al-Hf , Phase , diagram , Al3Hf , precipitate , Microstructure , Properties