Ignition-proof performance and mechanism of AZ91D-3Nd-xDy magnesium alloys at high temperatures

China Foundry

Yong-yan Li¹  Jian Ding¹  Wei-min Zhao¹ 

[1] School of Materials Science & Engineering, Hebei University of Technology, Tianjin 300132, China;

关键词: AZ91D;    Nd;    Dy;    ignition-proof;    high temperature;   

DOI  :  10.1007/s41230-018-7104-8

来源: DOAJ

【 摘 要 】

This study focused on the synergistic effect of alloying elements neodymium (Nd) and dysprosium (Dy) on the ignition-proof performance of AZ91D alloy. The ignition-proof mechanism of AZ91D-3Nd-xDy (x = 0.5, 1.0,1.5, 2.0 and 2.5wt.%) alloy was discussed in depth through ignition-proof testing and microstructure observation. The results showed that the AZ91D-3Nd-2Dy alloy exhibited the highest ignition-point of 893 K, increased by 69 K as compared to the AZ91D alloy. The ignition-proof mechanism of Nd and Dy additions lay in three aspects: (1) the formation of denser oxide film consisting of Dy2O3 and MgO improves the oxidation resistance of the alloy, (2) the great reduction of the low melting-point phase β-Mg17Al12, which leads to the decrease in the oxygen diffusion channels, and (3) the newly formed high melting-point phases (Al2Nd and Al2Dy), which block the oxygen diffusion channels and prevent the chemical reaction of Mg and oxygen.

【 授权许可】

Unknown