论文部分内容阅读
研究了780℃下静置不同时间,Mg-Nb-Zn-Zr合金中Zr含量、形态和分布的变化以及Zr衰退对晶粒粗化的影响。用电感耦合等离子体(ICP)质谱仪检测Zr含量的变化,用金相显微镜观察合金微观组织,用带能谱的扫描电镜分析Zr核形态及分布。结果表明:Zr含量在静置2 h内迅速下降到一定值,继续静置对Zr含量的影响不大;静置时间延长晶粒逐渐长大,由原来的等轴状细小晶粒发展成胞状晶甚至树枝晶;随静置时间延长,富Zr核心减少,Zr核由不规则形状逐渐转变为球状。静置过程对Mg-Nb-Zn-Zr合金的硬度影响不大。
The effects of Zr content, morphology and distribution in the Mg-Nb-Zn-Zr alloy and the decline of Zr on grain coarsening at 780 ℃ for different time were studied. The changes of Zr content were measured by Inductively Coupled Plasma (ICP) mass spectrometer. The microstructure of the alloy was observed with a metallurgical microscope. The morphology and distribution of Zr nucleus were analyzed by scanning electron microscope with energy dispersive spectroscopy. The results show that the content of Zr rapidly drops to a certain value within 2 h after it is left standing, and the effect of standing still has little effect on the Zr content. The grain grows gradually when it is allowed to stand for a long time and grows from the original equiaxed small grains into cells Crystal or even dendrite. With the prolongation of standing time, the Zr-rich core decreases and the Zr nucleus gradually changes from an irregular shape to a spherical shape. The static process has little effect on the hardness of Mg-Nb-Zn-Zr alloy.